This PDF file contains the front matter associated with SPIE Proceedings Volume 8793 including the Title Page, Copyright information, Table of Contents, Introduction, and Conference Committee listing.

Electrospun nanofibres as the potential reinforcement in manufacturing composite materials are recently attractive due to their simple fabrication process via electrospinning to produce continuous fibrous structures. This study concentrates on the development of novel epoxy composites laminated by layers of electrospun polylactic acid (PLA) nanofibre mats to evaluate their mechanical and thermal properties by means of flexural testing and differential scanning calorimetry (DSC), respectively. The moulded composite sheets were prepared at the fibre contents of 3 wt%, 5 wt% and 10 wt% using a solution casting method. The flexural moduli of composites have been shown to be increased by 50.8% and 24.0% for 5 wt% and 10 wt% fibre contents, respectively, as opposed to that of neat epoxy. This similar trend was also found for corresponding flexural strengths being increased by 31.6% and 4.8%. However, the flexural properties become worse at the fibre content of 3 wt% with decreases of flexural modulus by 36.9% and flexural strength by 22.9%. The examination of fractured surface morphology of composites using scanning electron microscopy (SEM) confirms a full penetration of cured epoxy matrix into electrospun PLA nanofibres despite some existences of typical fibrous structures/networks detected inside the large void cavities. On the other hand, the glass transition temperatures of composites have increased to 54-60°C due to the addition of electrospun fibres as compared to 50°C for that of epoxy, indicating that those fibrous networks may further restrict the intermolecular mobility of matrix for thermal effects.

Polylactic acid (PLA)/coir fibre biocomposites were fabricated using a compression moulding technique. The effects of fibre content (5-30 wt%) and fibre treatment on mechanical, thermal and biodegradable properties of biocomposites were holistically investigated via mechanical testing, scanning electron microscopy (SEM), differential scanning calorimetry (DSC) and soil burial method to understand the applicability of manufacturing eco-efficient and sustainable “green composites”.

This study developed a novel drug carrier based on functional modified bacterial cellulose(BC) which was conjugated with Ibuprofen(IBU) by esterification. BC-Ibuprofen as the macro- molecular prodrugs and drug carrier used to improve the short half-life of the drug, and was able to control release through the hydrolysis of ester bond between the hydroxyl groups of BC with Ibuprofen under different condition. Fourier transform infrared analysis revealed that Ibuprofen had been successfully grafted onto the bacterial cellulose (BC). Thermal and morphological characterization indicated the formation of the BC-Ibuprofen system incompletely reacted maintained the bulk structure of the pristine material such as crystallinity, 3-dimentional network and so on. The drug release behaviours were affected by the ester bond hydrolysis as well as the microstructure characteristics of the modified nanofiber. The release of BC-IBU showed an apparent pH-dependent, fast in alkaline and acid solution but slow relatively in neutral. Such pH-responsiveness, in addition to its morphological characteristics, in this paper suggested a great potential of BC-IBU as a more effective, safe, and stable prodrug candidate.

In this study, cotton fabric and coconut shell were integrated in particleboard to reduce the use of wood. Particleboards containing mixed rubberwood and coconut shell with an equal weight ratio have been integrated with various layers of cotton fabric. These materials were bonded by urea formaldehyde with a content level of 12% by weight. Flexural and water absorption tests were conducted to analyze its mechanical properties and dimensional stability. Results of flexural test showed an increment at least double strength values in fabricated materials as compared to control sample. The existence of fabric in the particleboard system also improved the dimensional stability of the produced material. Enhancement of at least 39% of water absorption could help the dimensional stability of the produced material. Overall, these new particleboards showed better results with the incorporation of cotton fabric layers and this study provided better understanding on mechanical and physical properties of the fabricated particleboard.

Chemical sensors made of tailored nanoparticles offer excellent miniaturization capability and are able to rapidly and continuously detect trace amounts of important analytes down to trace concentrations. Application of these sensing materials to non-invasive medical diagnostics by breath analysis has the potential to drastically reduce diagnostics costs while offering better service quality to the patients and enabling very early-stage detection of severe illnesses such as lung cancer. Here, we present a flexible approach to synthesize advanced solid-state gas sensor materials that have demonstrated reliable detection of important breath markers. In particular, the feasibility of capturing highly performing, meta-stable sensing nanoparticles by flame-synthesis of multi component metal-oxides is critically discussed.

Vacuum frying with pre-treatment of potato crisps are potentially effective processes on the improving the crispness of potato crisps. Pre-drying and subsequent sugar dipping are considered as an advantageous process as the pre-treatment of potato crisps to reduce considerable amount of oil uptake. In this study, potato crisps were blanched, pre-dried, and dipped in the solution of sugar (23.07%, in 2 seconds) before vacuum frying at 120 °C, 110 °C with vacuum pressures, which is 150 mbars. The results were collected by testing the crispiness of the potato crisps with the three-point-support method and using an Instron Universal Testing Machine through the texture parameters: Maximum Peak Force; Slope of Initial Tangent, Hardness, Stiffness, Firmness, Modulus of Elasticity and Maximum Tensile Stress. There was a significant improving in physical properties of crisps observed. Crisps that had been pre- treatment and vacuum- fried at 110 °C (150 mbars) had much improving in crispness (50%) including the hardness (170%), stiffness (140%), firmness (50%) and modulus of elasticity (60%) compared with normal frying at 180 °C without pretreatment and vacuum frying. The effect of vacuum frying and the pre-treatment technique on the improving the physical properties of crisps was evaluated. The shrinkage of potato crisps after frying was also considered in this research. The color and microstructure of potato crisps with pre-treatments and vacuum frying have also been obtained.

Over the last few years a number of sensing platforms are being investigated for their use in drug development, microanalysis or medical diagnosis. Lab-on-a-chip (LOC) are devices integrating more than one laboratory functions on a single device chip of a very small size, and typically consist of two main components: microfluidic handling systems and sensors. The physical mechanisms that are generally used for microfluidics and sensors are different, hence making the integration of these components difficult and costly. In this work we present a lab-on-a-chip system based on surface acoustic waves (for fluid manipulation) and film bulk acoustic resonators (for sensing). Coupling surface acoustic waves into liquids induces acoustic streaming and motion of micro-droplets, whilst it is well-known that bulk acoustic waves can be used to fabricate microgravimetric sensors. Both technologies offer exceptional sensitivity and can be fabricated from piezoelectric thin films deposited on Si substrates, reducing the fabrication time/cost of the LOC devices.

Piezoelectric composite sensors which consist of a ferroelectric ceramic phase and a polymer binder have been the center of interest for offering a distributed sensing mechanism in many industrial applications. This study investigates the effect of PZT surface modification on the mechanical and piezoelectric properties of PZT/epoxy composite sensors. Lead zirconate titanate ceramic powder (PZT-5H) was surface modified to prepare a high PZT content (0-3) piezoelectric composite sensor. Functional groups of the modifiers grafted onto the PZT particle surface served as a bridge into the epoxy matrix, thus creating strong bonds between the matrix and PZT particles. This noticeably improved the dispersion of the PZT phase, allowing the use of large fractions of piezoactive component in the composite. It is demonstrated that the produced piezo-film shows an enhanced poling behavior in that it can be poled with lower voltages under reduced poling times. This is caused by greater levels of microstructural homogeneity in the modified films as well as alteration of interfacial charge characteristics using modifiers’ functional groups.

When faced with the task of monitoring the indoor environment of a coal mine shaft, obtaining air velocity measurements is beneficial in considerations such as environmental impact, energy consumption and safety. To fulfill this demand, our research focuses on the design, construction and characterization of an economical three-dimensional ultrasonic anemometer, as well as the evaluation of its performance in combination with a Kalman filter algorithm. Our instrument was characterized using a wind tunnel in a process that included sixteen runs to both examine the distortion of the measurements caused by the sensor structure, and then to calibrate its response to changes in speed and direction of the incoming airflow, and three runs to assess the performance of the calibrated instrument. The results showed the instrument capable of obtaining wind velocity at a maximum frequency of 20Hz, with measurement accuracy of ±(5° ± 1% FS) in orientation and ±(0.8 m/s ± 4% FS) in wind speed, under reference conditions of 9 m/s wind speed and up to 15° from the horizontal wind incidence. The implementation of the Kalman filter resulted in improved accuracy of the wind direction measurement and enabled the anemometer to recursively extract the average velocity of highly-turbulent air currents.

During the past decade, many successful studies have evidently shown remarkable capability of Fiber Bragg Gratings (FBG) sensor for dynamic sensing. Most of the research works utilized the 1550 nm wavelength range of FBG sensors. However near infra-red (NIR) FBG sensors can offer the lower cost of Structural health Monitoring (SHM) systems which uses cheaper silicon sources and detectors. Unfortunately, the excessive noise levels that experienced in NIR wavelengths have caused the rejection of sensor that operating in this range of wavelengths for SHM systems. However, with the appropriate use of signal processing tools, these noisy signals can be easily ‘cleaned’. Wavelet analysis is one of the powerful signal processing tools nowadays, not only for time-frequency analysis but also for signal denoising. This present study revealed that the NIR FBG range gave good response to impact signals. Furthermore, these ‘noisy’ signals’ response were successfully filtered using one dimensional wavelet analysis.

Shape memory polymer composites (SMPC) release device can be fabricated to solve the disadvantages of traditional explosive release device, such as large weight, bad stability, and strong impact force and damage due to explosion. The release device is made up of two thin-walled tubes, the first one is responsible for the torsion, and the second is used to fit the first tube. The tubes are made from carbon fiber reinforced styrene-based shape memory polymer (SMP). Resistor heater is applied to heat the device and actuate the shape recovery process. This SMPC release device can connect the main device and the device which need released. When the instruction comes, it can separate the two devices immediately. Firstly, the first tube is heated by the resistor heater, then the twisting and stretching force is exited on the heating part of the tube, unloading after cooling, the two thin-walled tubes of release device is connected. Secondly, the twisted part of the first tube is heated, it twisted to the original angle, and then the stretched part drew back to the original shape after heating. So the working part pulled the claws of it out of the second tube automatically, and separated the release device to two parts, thus the release is completed. Optimal solutions are designed to achieve high driving efficiency. This paper has evaluated the strength and verified the feasibility of the SMPC release device, measured the tensile strength and the reverse effect, compared with the theoretical and experimental results. Finite element analysis is used to simulate the deformation.

Porphyrin is a type of polymer which can combine with multiple heavy metal ions.Some structures and properties of porphyrin will get changed with this combination.We can detect these changes of structures or properties of porphyrin to know how the combination between them goes on.In this paper,we get the giant porphyrin capsule in two consecutive micro-fluidic junctions.We can observe strong red fluorescence under green laser excitation.Then we use Mn²⁺ to react with this capsule.Mn²⁺ can combine with porphyrin and influence the intensity of the red fluorescence.Different concentration of Mn²⁺ solution has different effects on the intensity of fluorescence.So we can make sense of how the combination is between the two substance.

A robotic surgical device, actuated by Ionic Polymer-metal Composite (IPMC), integrated with a strain gauge to achieve force control is proposed. Test results have proved the capabilities of this device to conduct surgical procedures. The recent growth of patient acceptance and demand for robotic aided surgery has stimulated the progress of research where in many applications the performance has been proven to surpass human surgeons. A new area which uses the inherently force compliant and back-drivable properties of polymers, IPMC in this case, has shown its potential to undertake precise surgical procedures in delicate environments of medical practice. This is because IPMCs have similar actuation characteristics to real biological systems ensuring the safety of the practice. Nevertheless, little has been done in developing IPMCs as a rotary joint actuators used as functional surgical devices. This research demonstrates the design of a single degree of freedom (1DOF) robotic surgical instrument with one joint mechanism actuated by IPMC with an embedded strain gauge as a feedback unit, and controlled by a scheduled gain PI controller. With the simplicity of the system it was proven to be able to cut to the desired controlled force and hence depth.

Wind energy is seen as a viable alternative energy option for future energy demand. The blades of wind turbines are generally regarded as the most critical component of the wind turbine system. Ultimately, the blades act as the prime mover of the whole system which interacts with the wind flow during the production of energy. During wind turbine operation the wind loading cause the deflection of the wind turbine blade which can be significant and affect the turbine efficiency. Such a deflection in wind blade not only will result in lower performance in electrical power generation but also increase of material degradation due high fatigue life and can significantly shorten the longevity for the wind turbine material. In harnessing stiffness of the blade will contribute massive weight factor and consequently excessive bending moment. To overcome this excessive deflection due to wind loading on the blade, it is feasible to use shape memory alloy (SMA) wires which has ability take the blade back to its optimal operational shape. This paper details analytical and experimental work being carried out to minimize blade flapping deflection using SMA.

Fiber Optics Polarimetric Sensors (FOPS), utilizing first fundamental frequency mode and its harmonics, have already been used as damage detection tool. The FOPS technology is attractive in damage detection as it facilitates us with real time non-destructive health monitoring of different mechanical and civil structures. In this paper, the effects of the size and the location of a single crack on the frequency of first fundamental mode of a cantilever beam have been studied. A relation between the relative size of a crack and relative change in the first fundamental frequency has been established theoretically and then verified experimentally. Further, it has been shown that the cracks, close to the fixed end of the cantilever beam, have significant effect on the frequency of first fundamental mode and as the crack moves away from the fixed end, the effect on the frequency starts becoming diminished. Also the sensitivity of Fiber Bragg Grating (FBG) sensor against a single crack has been studied along both the directions; parallel to the axis of FBG sensor and perpendicular to the axis of FBG sensor. Experimental results show that the range of sensitivity in both the directions is almost the same bur FBG is more efficient along its axis.

Sulfate attack is one of the most frequent environmental attacks affecting concrete structures, which is manifested by expansive disruption and deterioration of cement paste. However, it is difficult to monitor the deterioration induced by sulfate attack as these attacks mainly occur in sulfate-bearing soils or ground waters. In this paper, the tentative experimental investigation on sulfate attack monitoring was carried out by using smart aggregate transducers and an active sensing method is proposed. A number of plain concrete columns with embedded smart aggregates were fabricated and then suffered to salt-fog exposure for several months. Active monitoring methods were performed to detect the deterioration of the specimens using smart aggregates. In addition, testing of the mechanical properties and water absorption ability of concrete specimens at different deterioration times was performed as well. Then the transmission mechanism of stress wave in concrete was discussed. The experimental results show that, with the growth of attacking time, the amplitude of the received signal decreased, and by calculating the damage index, the deterioration degree of concrete specimens was estimated. It is indicated that the proposed piezoceramic based SA monitoring method is valid in sulfate attack monitoring.

Chemical vapor deposition (CVD) diamond film has broad application prospect as heat sink in microelectronic field for its excellent thermal conductivity. The micro CVD diamond heat sinks with the size of 50μm×100μm×2000μm were prepared using mould copy technique. The micro silicon moulds for deposition of micro CVD diamond heat sinks were fabricated using inductivity coupling plasma (ICP) etching process. Micro CVD diamond heat sinks were synthesized under 2% methane and 98% hydrogen by hot filament CVD (HFCVD) method. The micro CVD diamond heat sinks were investigated by SEM, Raman and photo thermal deflection. The results show that favorable micro CVD heat sinks having a thermal conductivity of 960W·m^-1·K^-1 can be prepared by mould copy technique.

The room temperature deposition of self-assembling silica nanoparticles onto D-shaped optical fibres (“D-fibre”), drawn from milled preforms fabricated by modified chemical vapor deposition, is studied and preliminary results reported here. Of various techniques explored, an automated “dip-and-withdraw” approach is found to give the most reproducible layers. Vertical dip-and-withdraw produces tapered layers with one end thicker (surface coverage < 0.85) than the other whilst horizontal dip-and-withdraw produces much more uniform layers over the core region. The problem of induced fracturing is shown to originate from the sides of the D-fibre flat, attributed to an extended, linear “coffee stain effect”, and is greatest for horizontal dip-and-withdraw. Under optimal preparation conditions they can be minimised and prevented from extending over the core region. Alternatively, these structures can be made periodic potentially enabling some unique structures to be fabricated since post-deposition of functional species will be highest in these cracks.

Structural Health Monitoring Systems based on embedded FBG sensors, to identify damage conditions, are largely dependent on the spectral distortion of the sensors. The uneven stress gradient occurring along the grating of FBG sensors, due to damage inside composite structures can be estimated by analysing significant changes that appear in the FBG response spectra. However, the stochastic nature of the distorted shape of the FBG spectra makes it difficult to interpret and quantify the existing damage at the location of the FBG sensors. There are several indexing methods proposed by researchers. We have previously presented a novel concept of the “Distortion Index (DI)” which is defined using distorted spectra of FBG sensors. It was observed that the DI increases with the increase in damage size. The Distortion Index (DI) is introduced to create a correlation between the damage and the distortion of the response spectra of a FBG sensor. This index provides the ability to generalise the distortion of FBG spectra for a particular structure. The index can be used to quantify the damage in the structure relative to its original condition, which can be the condition of structure during a regulated time, i.e. a month uninterrupted operation or first hours in operation, of a structure can be used as no damage condition. In this paper we discuss the application of distortion index and comparison with available several other indexes.

Fibre optic sensors where embedded in an FRP panel during manufacture. Strain data was collected under uniform distributed loading and used to inversely predict distributed loads. A square FRP panel was manufactured while embedding an FBG sensor network. The panel was tested under various uniform distributed loads. Sensor data was collected and a strain signature was developed for each load case. A Finite Element Analysis was used to predict strain data at sensor locations and these were found to correlate well with the experimental values. Software was used to inversely predict distributed loading from the strain data with good accuracy. It was found with FEA and experimentally that the number of sensors could be reduced for this type of loading.

There is an urgent need to improve the fire performance of fibre composites so that they can be used in infrastructure applications. Nanoparticles from clay has been well known as a potential precursor of nanocomposites because of the significant improvement in mechanical properties and their availability. Nanoclay contains very thin layers of silicates, in which the octahedral sheet of alumina is sandwiched between two tetrahedral sheets of silica. Montmorillonite (MMT) nanoclay, the most widely used type, is often treated with cation-organic surfactants to render it organophilic. The addition of 3-5% organophilic clay into polymeric matrix can enhance the mechanical and thermal performance of the nanocomposite. Most research projects on clay nanocomposites were carried out with more focus on their improvement of mechanical properties. However, the effect of nanoclay on the fire performance of hybrid composites has not been covered comprehensively. In this study, the effect of organoclay on the fire performance of the hybrid nanocomposite was investigated. Epoxy and glass fibre reinforcement were chosen as they have been proven to be more suitable and feasible for civil infrastructure applications. The fire characteristics of the hybrid nanocomposite were evaluated using cone calorimeter tests conducted according to ISO 5660-1.

Electrically induced flapping motion of aluminum foil with a high frequency is demonstrated. The flapping motion was recorded by using a high speed camera and characterized by analyzing the tip displacement of the foil. It is found that a critical voltage presents to induce the flapping motion and the vibration frequency depends on the dimensions of the foils as well as the dielectric properties of the supporters for the foil. Induced directional airflow by the flapping motion was also demonstrated here. This study may provide a simple way to realize the two-dimensional flying vehicle in the future.

This paper mainly studies the response of high-temperature optical fiber sensor applied to different hot structural materials. Strain and temperature sensitivities of the optical fiber are discussed. The heat test on the bare FBG shows that wavelength and temperature are not of a simple linear relationship, and that using a quadratic function description is more reasonable at high temperature. A type of silica optical fiber sensor is attached to different structures using a special high-temperature adhesive. Two kinds of high-temperature materials, high-temperature alloy and ultra-high temperature ceramic, are used as the base materials. Experiments are carried out to break through the connection technology at high temperature. The response of temperature and strain are measured simultaneously from room temperature to maximum 750°C. The response differences are compared by using the signal decoupling method. The relationship between wavelength change and structural thermal strain is studied; the first-order and the second-order temperature sensitivities coefficients are given for different materials. Through the experiment, the different strain transfer coefficients are given in the two cases. This study realized the concurrent monitoring of structural temperature and strain at high-temperature situation using only one sensor, and thus provides a new way for hot structure health monitoring in high-temperature environment.

In this work, we have firstly electrodeposited small gold seeds (average diameter of ~40 nm) onto transparent indium tin oxide (ITO) thin film coated glass. Then silver triangular nanoplates with edge lengths of ~200 nm were fabricated using seed-mediated growth method. The localized surface plasmon resonance (LSPR) peak was located at ~700 nm. Finally, a label-free plasmon immunosensor was prepared by directly immobilizing goat anti-mouse IgG onto silver surface. The performance of the LSPR immunosensor was investigated. The red-shift of the biosensor was linearly proportional to mouse IgG concentration ranged from 5 ng/mL to 500 ng/mL, with a detection limit of 2 ng/mL. The label-free immunosensor was simple, sensitive and selective.

Asymmetric carbon fibre reinforced aluminum alloy laminates was manufactured for the purpose with repeat tensile test, which will be applied in composite pressure vessel. Ultrasonic C scan and A scan approach are used to evaluate the damage of the asymmetric CFRP-Al (carbon fibre reinforced aluminum alloy) laminates. Nondestructive detection is carried out for the CFRP-Al laminates before and after tensile test. Comparison results and pulse echo analysis show that when subjected to repeat tensile test with 70% elastic limit strain load of the CFRP laminates, the interface debonding between CFRP and Al will not occur but the delamination within CFRP laminates becomes the main damage of the asymmetric CFRP-Al laminates. This investigation indicated that combined ultrasonic C scan and A scan is available for damage evaluation of fibre metal laminates.

Moxa Moxibustion is a common traditional Chinese therapy in which burning Moxa is applied to affected body areas. This method has been employed for thousands of years to achieve certain medical objectives, such as pain relief or antibacterial and anti-inflammatory effects. Its therapeutic effectiveness has been demonstrated successfully both in research and clinical studies. However, this traditional approach may cause undesirable side effects, for example: 1) burning of Moxa produces by-products such as smoke and ash; 2) patients are at risk of being burnt; 3) the active ingredients of the Moxa leaf oil are volatile, odorous, unstable in air and easy to dissipate, and difficult to store and transport; 4) it is inconvenient to operate. These side effects limit its further high-potential and high-value applications. This study is aimed at developing a multi-functional smart textile system that will adopt smart fabrics containing encapsulated Moxa oil integrated with thermally conductive materials to replace the conventional Moxa products. This will efficiently deliver the active ingredients of Moxa to a human body at optimum conditions, i.e., in a precise and controllable way, with maximum convenience and a high level of comfort. Doing so would solve the existing problems mentioned above. Both garment design skill and textile technology will be applied to Moxa Moxibustion textile to enhance the aesthetics and functionality. The smart garment performance will be assessed subjectively in a clinical trial and objectively by a number of instrumental methods.

Graphene platelets (GnP) are new class of fillers in nanosize with high aspect ratio, high absolute strength with good compatibility to reinforce most polymers. In this study, we produce GnPs with a scalable and cost effective method using thermal shock followed by ultrasonication. AFM analysis shows that our GnPs consists of 3 – 4 layers since it has a thickness of 3.55 ± 0.32 nm. Thermally and electrically conductive elastomer/GnPs nanocomposites have been developed using melt compounding technique. The fabricated nanocomposites show high mechanical performance combined with good functional properties. At 24 vol% of GnP, tensile strength, Young’s modulus, and tear strength improved by 230%, 506% and 445%, respectively with an increase of thermal conductivity by 240%. The percolation threshold of electrical conductivity was reported at 16.5 vol%.

Hybrid thin films of multi-walled carbon nanotube (MWCNT) and titania were fabricated on quartz slides by alternatively depositing MWCNT and titanium(IV) bis(ammonium lactato) dihydroxide (TALH) via a solution based layer-by-layer (LbL) self-assembly method followed by calcination to convert TALH to crystalline titania. The multilayer film build-up was monitored by UV-vis spectroscopy which indicated the linear growth of the film with the bilayer number. XRD confirmed the formation of anantase titania after heat treatment. The photocatalytic property of the hybrid thin film was evaluated by its capacity to degrade rhodamine B under the UV illumination. Compared with pure TiO₂ film, experiments showed that the MWCNT/TiO₂ hybrid film had a much higher photocatalytic activity under the same conditions. The first order rate constant of photocatalysis of 30 bilayers of hybrid film was approximately 8-fold higher than that of 30 bilayers of pure TiO₂ film. In addition, the degradation efficiency of MWCNT/TiO₂ hybrid thin film increased with its thickness while pure titania film remained unchanged. A 30 bilayers hybrid thin film that contains about 0.2 mg MWCNT/TiO₂ catalyst was capable of completely degrading 10 mL of 2 mg/L Rh B solution within 5 hours. The results also indicated that the hybrid catalyst could be reused for several cycles.

Adequate amount of graphene oxide (GO) was firstly prepared by oxidation of graphite and GO/epoxy nanocomposites were subsequently prepared by typical solution mixing technique. X-ray diffraction (XRD) pattern, X-ray photoelectron (XPS), Raman and Fourier transform infrared (FTIR) spectroscopy indicated the successful preparation of GO. Scanning electron microscopy (SEM) and Transmission electron microscopy (TEM) images of the graphite oxide showed that they consist of a large amount of graphene oxide platelets with a curled morphology containing of a thin wrinkled sheet like structure. AFM image of the exfoliated GO signified that the average thickness of GO sheets is ~1.0 nm which is very similar to GO monolayer. Mechanical properties of as prepared GO/epoxy nanocomposites were investigated. Significant improvements in both Young’s modulus and tensile strength were observed for the nanocomposites at very low level of GO loading. The Young’s modulus of the nanocomposites containing 0.5 wt% GO was 1.72 GPa, which was 35 % higher than that of the pure epoxy resin (1.28 GPa). The effective reinforcement of the GO based epoxy nanocomposites can be attributed to the good dispersion and the strong interfacial interactions between the GO sheets and the epoxy resin matrices.

Degradation phenomena can affect civil structures over their lifespan. The recent advances in nanotechnology and sensing allow to monitor the behaviour of a structure, assess its performance and identify damage at an early stage. Thus, maintenance actions can be carried out in a timely manner, improving structural reliability and safety. Structural Health Monitoring (SHM) is traditionally performed at a global level, with a limited number of sensors distributed over a relatively large area of a structure. Thus, only major damage conditions are detectable. Dense sensor networks and innovative structural neural systems, reproducing the structure and the function of the human nervous system, may overcome this drawback of current SHM systems. Miniaturization and embedment are key requirements for successful implementation of structural neural systems. Carbon nanotubes (CNTs) can play an attractive role in the development of embedded sensors and smart structural materials, since they can provide to traditional cement based materials both structural capability and measurable response to applied stresses, strains, cracks and other flaws. In this paper investigations about CNT/cement composites and their self-sensing capabilities are summarized and critically revised. The analysis of available experimental results and theoretical developments provides useful design criteria for the fabrication of CNT/cement composites optimized for SHM applications in civil engineering. Specific attention is paid to the opportunities provided by new RF plasma technologies for the functionalization of CNTs in view of sensor development and SHM applications.

Single-walled carbon nanotubes (SWNTs) possess outstanding electrical properties, which make them attractive building blocks for future electronics. The electrical properties of SWNTs are intimately related to their structural uniformity. Here, we reported well-aligned SWNTs, up to centimeter long, synthesized in an ultralow gas flow chemical vapor deposition (CVD) system using ethanol as the carbon source. The as-grown SWNTs were characterized using Raman spectroscopy and confocal Raman imaging. The low intensity ratio of D band and G band (ID/IG), together with the constant G band position over several millimeter length of an isolated SWNT, indicates that the structures of the individual SWNTs are uniform with exceedingly low density of defects. Excellent electrical performances were also observed by fabricating the as-grown SWNTs into FETs. The superior length and the well-ordered orientation, allow large scale fabrication of individual CNT-based electronic devices, and also show a promising prospect of creating integrated circuits on an individual SWNT.

Carbon Nanotube (CNT), for its excellent mechanical, electrical properties and nano size, large special surface physical property, become the most promising material. But carbon nanotube can still fabricated in micro dimension, and can’t be made into macro size, so to the carbon nanotube filled composite can’t explore the properties of the CNT. Carbon nano-paper is made of pure CNT, with micro pore, and it turn micro sized CNT into macro shaped membrane. Based on the piezo-resistivity and electrical conductivity of the carbon nano-paper, we used the carbon nano-paper as functional layers fabricate functional composite, and studies its strain sensing, composite material deicing and shape memory polymer (SMP) material electric actuation performance. The results shown that the resin can pregnant the nano paper, and there was good bond for nano paper and composite. The functional composite can monitoring the strain with high sensitivity comparing to foil strain gauge. The functional composite can be heated via the carbon nano paper with low power supply and high heating rate. The composite has good deicing and heat actuation performance to composite material. For the good strain sensing, electric conductivity and self-heating character of the carbon nano-paper composite, it can be used for self sensing, anti lightning strike and deicing of composite materials in aircrafts and wind turbine blades.

Anelastic spectroscopy and rheometrics were used to study the viscoelastic properties of polystyrene/C₆₀ nanocomposites. 0.1 wt%, 0.5 wt%, 1 wt% and 2 wt% C₆₀ were added to pure polystyrene via melt compounding. Both storage modulus and viscosity decreased obviously when 0.1 wt% C₆₀ was added and it was ascribed to the increase of free volume around C₆₀ nanoparticles. Both glass transition and liquid-liquid transition moved to high temperature, which was associated with the confinement effect of the nanoparticles. The addition of C₆₀ influenced chain packing of polymer melts. The increase of free volume loosened the interaction between chain segments and nanoparticles on small size scale. So, the change of segment dynamics was not very obvious. On the contrary, the change of whole chain dynamics was very obvious. This can be explained by the fact that the influence coming from the increase of free volume was neglectable and the filler confinement of nanoparticles played an important role. The C₆₀ nanoparticles were looked as attractors of the polymer chains, which divided the long chains into several segments leading to decrease the fragility of the nanocomposites.

Due to their high light absorption, size dependent bandgap and low material usage and low cost of fabrication, quantum dots (QDs) are a close second to the conventionally used dyes for the dye-sensitised solar cells (DSCs). TiCl₄ treatment is one of the typical methods used to treat the anode or the working electrode of DSCs for performance improvement. In this work, the effect of TiCl₄ treatment on the performance of CdSe/CdS-sensitised solar cells was studied. The devices made without TiCl₄ treatment, perform with a moderate 1.83% efficiency under AM1.5, 1 sun illumination conditions. In contrast, TiCl₄ treated working electrodes helps to enhance the cell efficiency to 3.98%, mainly from a higher photocurrent density (15.4 mAcm^-2) and fill factor (0.51). Higher loading of the quantum dots in the working electrode and passivation effect due to TiCl₄ treatment are believed to be responsible performance improvement.

An inorganic polymer is formed by dissolution of aluminosilicate solid materials in a strong alkaline activator solution, polymerization, gelation and/or crystallization. This material possesses many superior properties to normal organic polymers, such as high temperature resistant and non-flammable. This study aims to explore the possiblity of using inorganic polymers as a fire resistant building material. Inorganic polymer foams containing ~8% of Na₂O (mass ratio to solid materials) and 45-50% porosity (in volume) are synthesised from fly ash and slag and with sodium silicate solution as activator. The compressive strength, volumetric stability and phase features of the porous inorganic polymers before and after exposed to 100, 400 and 800^oC temperatures are determined and analysed. After exposure to high temperature, the inorganic polymer foam without slag addition maintains the compressive strength at 100^oC and 400^oC and increases by 40% at 800^oC. In contrast, the foam that contains 20% slag, although which has a much higher initial strength than the non-slag foam, can only maintain the strength at 100^oC but lose strength dramatically at 400 and 800^oC. The measurement of volumetric stability and XRD analysis indicate that the larger shrinkage of slag-containing foam and the decomposition of calcium silicate phases under high temperatures is accounting for the large strength loss. The current study shows a possibility to develop a kind of new building material with the function of transforming from nonstructural to structural upon fire.

This paper focuses on the comparison of various types of matrix materials and their mechanical properties for development of syntactic foams for marine applications. Generally, syntactic foams are close pore foams fabricated by the mechanical mixing of hollow microsphere particles in a polymeric matrix resin. From the literature review, it was found that there are several polymeric resins that have been used for development of syntactic foams such as epoxy, cyanate ester, polypropylene, polysialate and vinyl ester. In this paper, a comparative discussion is presented on the mechanical properties of hollow glass particles mixing with polymeric resins for development of syntactic foams for the use of these composites in bulk applications such as marine structures.

Experimental investigation and efficient control of magnetorheological (MR) damper towards smart energy absorption of composite structures are presented in this paper. The evaluation of an existing MR damper based on the damping force presented in our earlier work is limited by the experiment configuration setup. Using two arms configuration, an experimental test rig is designed to overcome this limitation and enabled the MR damper to be investigated throughout its full velocity range capability. A controller is then developed based on the MR damper investigation to provide automated variable control of induced current with a set crushing force and available data of composite tube crushing force. The controller is assessed numerically and shows that MR damper is controlled to provide consistent crushing force despite oscillation from the composite tube crushing force. This, thus, shows promise of MR damper integration towards smart energy absorption of composite structures.

For exploring the behaviour of alkali-aggregate reactivity (AAR) in alkali-activated geopolymeric materials and assessing the procedures for testing AAR in geopolymers, the expansion behaviour of fly ash based geopolymer mortars with pure silica glass and typical carbonate rocks were studied respectively by curing at various conditions, i.e. 23°C and 38°C with relative humidity over 95%, immersed in 1M NaOH solution at 80°C. Results show that, at various curing conditions, neither harmful ASR nor harmful ACR was observed in geopolymers with the criteria specified for OPC system. However, with the change of curing conditions, the geopolymer binder and reactive aggregates may experience different reaction processes leading to quite different dimensional changes, especially with additional alkalis and elevated temperatures. It suggests that high temperature with additional alkali for accelerating AAR in traditional OPC system may not appropriate for assessing the alkali-aggregate reactivity behaviour in geopolymers designed for normal conditions. On the other hand, it is hopeful to control the dimensional change of geopolymer mortar or concrete by selecting the type of aggregates and the appropriate curing conditions, thus changing the harmful AAR in OPC into beneficial AAR in geopolymers and other alkali-activated cementitious systems.

A highly sensitive flexible piezoelectric material is developed by using a composite nanofibers web of polymer and metal. The nanofibers webs are made by electrospinning a mixed solution of poly(vinylidene fluoride) (PVDF) and silver nanowires (AgNWs) in the co-solvent of dimethyl formamide and acetone. SEM images show that the obtained webs are composed of AgNWs doped PVDF fibers with diameters ranging from 200nm to 500nm. Our FTIR and XRD results indicate that doping AgNWs into PVDF fiber can enhance the contents of beta phase of the PVDF. UV-Vis spectrum shows a slightly red shift at 324 nm and 341 nm after the AgNWs doping into PVDF, proving the presence of interaction between AgNWs and the PVDF polymer chain. The piezoelectric constant d33 of the nanofibers webs tested with a homemade system, reveals a good agreement with FTIR and XRD characteristic, and the highest one is up to 29.8 pC/N for the nanofibers webs containing 1.5% AgNWs, which is close to that of poly(vinylidene fluoride-trifluoroethylene) (P(VDF-TrFE), 77/23). This study may provide a way to develop high-performance flexible sensors.

To date, majority shape adaptations of shape memory polymer (SMP) are thermo responsive. A desire for isothermal, remotely controlled shape adaptations of SMP has motivated examinations of other stimulus. We successfully construct novel TiO₂-polystyrene shape memory nanocomposites and investigate influence of the ultraviolet irradiation on the shape memory effect. This material is facilely fabricated by introducing TiO₂ into polystyrene SMP. The properties of TiO₂-polystyrene shape memory nanocomposites are characterized by X-ray powder diffraction (XRD), Fourier transform infrared spectra (FT-IR), dynamic mechanical analysis (DMA), and diffused reflectance spectrum (DRS). Deriving from photoelectric foundational properties of TiO₂, the TiO₂-polystyrene shape memory nanocomposites can absorb light energy and undergo intra-molecular or inter-molecular physical or chemical transformations. Furthermore, the results of this work provide a useful baseline upon which researchers could explore more interesting behaviors of photosensitive SMP composite and investigate other more challenging actuation problems.

Considerable efforts have been spent in the development of magnetic nanoparticles (MNPs) in the last decade to understand their behaviour, and the improvement of their applicability in many different areas. Precise control over the synthesis conditions and surface functionalization of MNPs is crucial because it governs their physical properties and their colloidal stability. The magnetic platforms possess very small size and narrow size distribution together with high magnetization values. These nanoparticles (NPs) must combine high magnetic susceptibility for an optimum magnetic enrichment and loss of magnetization after removal of the magnetic field. Computational Fluid Dynamics (CFD) approach has been used to investigate the impact of a magnetic field in ferrofluid flow through a T-microchannel. The microchannel consists of one 400μm wide main branch and two 200μm wide sidebranches. Available experimental data is used to validate the Eulerian-Eulerian approach in simulating the nanoparticles in flow flow under the influence of magnetic field. In general, magnetic nanoparticles are deflected across the suspending ferrofluid by negative magnetophoresis and confined by a water flow to the center of the micro-channel. The effect of ferrofluid flow rate on the particle focusing performance has been examined. It is found that the particle focusing effectiveness increases with decreasing flow rate.

Dielectrics with great electrocaloric effect (ECE) have great potential to be applied in modern refrigeration industry. Compared with the traditional refrigeration technology, it is environmentally friendly and has a higher efficiency. Researchers have found that compared with ECE occurring in ferroelectric phase, ECE in paraelectric state is giant. This paper is determined on calculating the ECE of several kinds of polar dielectric material so as to find some materials with giant ECE. First, we investigate the theoretical framework of ECE near the Ferroelectric-Paraelectric phase transformation, and we show the formula derivation of ECE near the Ferroelectric-Paraelectric phase transformation in the analytical method of the calculus derivation. Then we deduce the expression of phenomenological study parameters. Finally, we calculate the maximum temperature change, entropy change and the mechanical work of several kinds of dielectrics based on the expression deduced. We successfully find some dielectrics with giant ECE. The paper should offer great help in finding the dielectrics with giant ECE, which is of great value in application.

Stable and re-usable thermo-responsive hydrogel nanofibres were produced by electrospinning poly(Nisopropylacrylamide) (PNIPAM) in presence of a polyhedral oligomeric silsesquioxane (POSS) possessing eight epoxide groups, and of a 2-ethyl-4-methylimidazole (EMI) as a catalyst, followed by a heat curing treatment. The roles of the organic-base catalyst in the formation of crosslinked polymer network, fibre morphologies, and hydrogel properties were examined in this paper.

The effect of tool design on microstructure and properties of friction stir processed study aluminium alloy AA 5005-H34 (Al-Mg) was investigated using three different FSP tools with different pin designs. The application of FSP resulted in fine, fully recrystallised microstructures and the processed zone was defect-free for some of the pin designs. Significant grain refinement from an initial pancake-like microstructure with a grain size of about 192 μm in the base material to 10- 20 μm in the processed regions was achieved.

The strong light absorbing Cu₂ZnSnS₄ (CZTS) nanocrystals are interesting material in photovoltaic applications owing to the abundance and non-toxicity of the material. The optoelectronic property of CZTS light absorber depends on the size of nanocrystals which confines the electronic states within it. In the complex colloidal medium it is very difficult to predict the size of the particles by only theoretical calculations. However, suitable chemical approach is able to tune the size of the particles by adjusting the chemical potential of the medium for different sizes of CZTS nanocrystal formation. Here, we reported the size control of CZTS nanocrystals which were made by a hot-injection method using organic ligands based colloidal medium. The influence of solvent systems, within following five pure and mixing solvent systems: Oleylamine, 1-Octadecene + TOPO, mixture of Oleylamine:Oleicacid (1:1,v/v%), Oleicacid + TOPO and Oleylamine:Oleicacid (1:1,v/v%) + TOPO , and composition of metal precursors were studied. The final CZTS nanoparticles showed wurtzite crystal structures, and size of the particles can be tuned through different combination ratio of metal precursors. Our results indicate that metal precursor composition ratio has a pivotal role to tune the optoelectronic properties of CZTS nanocrystals for the photovoltaic applications.

Kinetic epoxy resin was filled with nanoclay to increase tensile properties of the composite for civil and structural. This project manufactured samples with different percentages by weight of nanoclay in the composites in steps of 1 wt %, which were then post-cured in an oven. The samples were then subjected to tensile tests. The results showed that the composite with 3 wt % of nanoclay produced the highest yield and tensile strengths. However, the Young’s modulus increased with increasing nanoparticulate loading. It is hoped that the discussion and results in this work would not only contribute towards the further development of nanoclay reinforced epoxy composites with enhanced material properties, but also provide useful information for the studies of fracture toughness, tensile properties and flexural properties of other composites.

The aim of this study is to investigate thermo-mechanical response of ZrO₂/Ti functionally graded materials (FGMs) fabricated by spark plasma sintering (SPS) based on a mean-field micromechanics model, which takes account of micro-scale stress relaxation due to interfacial diffusion between ceramic and metal phases as well as creep of both phases. A resistance to cyclic thermal shock loadings of FGMs with different compositional gradation patterns including Ti-rich, linear and ZrO₂-rich gradation patterns has been investigated. The results demonstrate that Ti-rich FGMs show superior properties among the tested FGM samples. Mean-field micromechanics-based examinations reveal that the range and ratio of thermal stresses in ZrO₂ surface layers in FGMs can affect cyclic thermal shock fracture behaviour but not mean thermal stresses.

Composites are materials made by combining two individual materials where one material forms the matrix while the other provides the reinforcement. A novel composite sandwich made up of glass fibre reinforced polymer (GFRP) face sheets and modified phenolic core has been developed recently. Although perfect bond between the skin and the core is a common assumption, an important issue that needs to be considered in using a composite beam is the development of debonding between the skin and the core. Debonding may arise during fabrication or under service conditions, which causes changes to the dynamic behaviour in addition to the strength degradation. This paper focuses on the effect of debonding on dynamic characteristics of sandwich beams of different debonding sizes and end conditions. Strand7 software is used for 3D finite element simulation. Free vibration behaviour reported in the literature for composite beams will first be used to compare the analytical results with the fully bonded and debonded beams. Study is extended to depict the effect of debonding on free vibration behaviour of novel composite beams. It is revealed that the decrease in natural frequency with the increase in the extent of debonding is more dependent on the width of debonding across the beam than the length along the beam. It is also perceived that full width debonding leads to increased participation of twisting modes in comparison to half-width debonding in clamped-clamped end condition. End conditions of the beam are a governing factor dictating which modes are more affected.

This study investigates the microstructure, optical absorption and photoelectric properties of nanostructured composites of TiO₂ nanotube arrays and SrTiO₃ or CeO₂ nanoparticles. The composites were fabricated by anodization and hydrothermal methods and their UV-visible and ultraviolet photoelectron spectra (UV-Vis and UPS) were measured to determine the band structures of the TiO₂-SrTiO₃ and TiO₂-CeO₂ heterojunctions. The heterojunctions are designed to promote the separation of photo-induced electron and hole (e-/h+) pairs when the nanostructured composites are adopted in photocatalytic or photoelectrode applications. Approximately 1.0 and 0.8 eV shifts in conduction band position were determined for the TiO₂-SrTiO₃ and TiO₂-CeO₂ heterojunctions, respectively. The photocurrent densities of the TiO₂- SrTiO₃ and TiO₂-CeO₂ composites were about 20 to 40% larger than that of the TiO₂ nanotube arrays under identical irradiation conditions. The size of the SrTiO₃ and CeO₂ nanoparticles, which could be controlled by the hydrothermal temperature and time, and the concentration of oxygen vacancies within the TiO₂ nanotubes were identified to be the key factors governing the photocurrent densities of the nanostructured composites.

Hybrid laminates consisting of woven glass fabric/epoxy composite plies and woven carbon fabric/epoxy composite plies are studied for fatigue damage and residual strength. A theoretical framework based on the systems approach is proposed as a guide to deal with the complexity involving uncertainties and a large number of variables in the hybrid composite system. A relative damage sensitivity factor expression was developed for quantitative comparisons between non-hybrid and hybrid composites. Hypotheses derived from the theoretical framework were tested and verified. The first hypothesis was that the difference between two different sets of properties produces shear stress in interface between carbon fibre reinforced plastics (CRP) and glass fibre reinforced plastics (GRP), and eventually become a source for CRP/GRP interfacial delamination or longitudinal cracking. The second hypothesis was that inter-fibre bundle delamination occurs more severely to CRP sub-system than GRP sub-system.

Engineered porous materials, which have fast absorption of liquids under global constraints (e.g. volume, surface area, or cost of the materials), are useful in many applications including moisture management fabrics, medical wound dressings, paper-based analytical devices, liquid molding composites, etc.. The absorption in capillary tubes and porous media is driven by the surface tension of liquid, which is inversely proportional to the pore size. On the contrary, the ability of conduction (or permeability) of liquid in porous materials is linear with the square of pore size. Both mechanisms superimpose with each other leading to a possibility of the fastest absorption for a porous structure. In this work, we explore the flow behaviors for the fastest absorption using heterogeneous porous architectures, from two-portion tubes to two-layer porous media. The absorption time for filling up the voids in these porous materials is expressed in terms of pore size, height and porosity. It is shown that under the given height and void volume, these two-component porous structures with a negative gradient of pore size/porosity against the imbibition direction, have a faster absorption rate than controlled samples with uniform pore size/porosity. Particularly, optimal structural parameters including pore size, height and porosity are found for the minimum absorption time. The obtained results will be used as a priori for the design of porous structures with excellent water absorption and moisture management property in various fields.

Production of activated carbons are a growing industry, and understanding to the processes involved in their synthesis is key to developing a better product. Generally the first step in the synthesis of activated carbon is the carbonisation of a material. During carbonisation the material undergoes aromatisation, and heteroatoms are removed, resulting in a highly aromatic carbon material. The physical and chemical properties are dependent on the degree of carbonisation and elemental makeup, which may be determined by the carbonisation conditions. In this study, properties of carbon chars derived from poly(divinylbenzene) are examined. Carbonisation conditions including, temperature, hold time, and atmosphere are studied to determine how these influence the thermal stability, elemental composition, and surface area and pore volumes of the final material. Surface areas were dependent on reactor gas, for nitrogen the surface area decreased from 665 m²/g to <1 m2/g as did pore volumes from 0.553 cm³/g to <0.01 cm³/g at 500°C; however, when the char was produced under an argon atmosphere, surface area and pore volume increased to 119 m²/g and 0.179 cm³/g. It was hypothesised that the difference between chars were due to a reaction of the char with nitrogen, which hindered the development of pores. Nitrogen reaction products were detected via elemental analysis and gas chromatography-mass spectrometry. This study shows the importance of the atmosphere and other parameters on the chars derived from poly(divinylbenzene).

The size effect of SiC particles on microstructures and mechanical properties of SiCp/Al composites produced by spontaneous infiltration technology was investigated. In this study, samples of SiCp/Al composites were fabricated using aluminum alloy ZL101 as the matrix material, and SiC particles with different sizes as reinforcement particles. The microstructures and micro-deformation of the samples were analyzed using optical micrograph, scanning electron microscope, energy dispersive spectrometer and WDW-50 respectively. The results show that the SiC particles can distribute uniformly in the aluminum matrix using the proposed method. Examing samples with different SiC particle sizes, the sample with the largest size of particle can significantly decrease the mechanical properties of the composites. Tensile strength of SiCp/Al composite increases along with a decrease in the size of SiC particles, but the ductility of the composites decreases. It was found that an obviously toughness fossa appeared in the fracture surfaces of composites, which indicated it behaviors tearing and plastic deformation characteristics.

Structures can go through harsh environmental adversity and can experience material loss and cracks during their service lives. Infill material is used to ensure a supporting bed for a grouted repair. Epoxy grouts are used for repairing and rehabilitating structures, such as foundations, bridges, piers, transportation pipelines, etc., because they are resistant to typical chemicals and possess superior mechanical properties than other grouts. The resin based infill used inside the void or cracked space of the repair is vulnerable to shrinkage. When these filled grouts have high resin content, cracks can develop from residual stresses, which can affect the load transfer performance. It follows that interlayer separation and cracking of infill layer can occur in a grouted repair. In this study, volumetric shrinkage of two epoxy grouts was measured over 28 days using a Pycnometer. The highest volumetric shrinkage measured after 7 days was found to be 2.72%. The results suggest that the volumetric shrinkage can be reduced to 1.1% after 7 days, through the introduction of a coarse aggregate filler; a 2.5 times reduction in shrinkage. About 98% and 92% of the total shrinkage over the 28 day period, of the unfilled and filled grouts respectively, was found to occur within 7 days of mixing. The gel-time shrinkages were also calculated, to determine the “postgel” part of the curing contraction which subsequently produces residual stresses in the hardened grout systems.

There is an increasing demand for powering on-person-devices (for communications, health-care purposes, and soldier protection) without the burden of the parasitic weight and toxicity of conventional batteries. This demand calls for an alternative power source from fibre-sized piezoelectric generators that can be integrated into garments. These piezopatches convert human movement induced mechanical strain on the fabric into electrical energy. In this paper, a dualfield computational analysis, combining harmonic and piezoelectric models, has been undertaken using the ANSYS Finite Element package. A Polyvinylidene Fluoride (PVDF) patch bonded to a material representative of a flexible fabric has been modeled in ANSYS. The electrodes are connected to a resistor that is matched to the piezo properties and loading conditions. The parametric variables used in this study include: surface area of the piezo-patches, aspect ratio, input force amplitude and the operational frequency. The complex interaction of these variables to the power output is explored and discussed in the context of the intended application. It is observed that the maximum output occurs at 5Hz for an optimal dimension of 400mm2 which makes it feasible as an energy harvesting system for low energy selfpowered electronics such as portable and wearable medical and communication devices.

The evolution and control of porosity in nanoporous platinum thin films have been studied both experimentally and by means of Kinetic Monte Carlo simulations. Experimentally, the sizes of the pores were controlled by a method of coarsening at different temperatures after dealloying. The KMC simulations also showed similar results which was governed by the temperature dependence of surface diffusion of the platinum atoms in the thin film. Good agreement is found between experimentally observed and simulated results.

Enhanced optical transmission of metallic nanohole arrays stimulated the blooming research efforts on plasmonics and rich applications. Here we studied the dependence of enhanced optical absorption on geometric parameters by nanohole arrays on gold films in infrared wavelength (8~12μm). An empirical modeling for enhanced optical absorption is summarized (based on a great many of simulation data and deviation analysis, and its goodness-of-fit test and significance test is acceptable), which takes consideration of not only single parameters but also interaction parameters of geometries. Through t-test, the interaction parameters with high significance are chosen, which could give high optical absorption, and the interaction of different parameters was evaluated via Analysis of Variance (ANOVA). Our study represents a new guiding rule for uncooled infrared detector design.

The Chemical Vapor Deposition (CVD) process is the simplest and cheapest method among various synthesis techniques for Carbon Nanotubes (CNT). The work reported here develops a mathematical model to represent CNT synthesis through catalytic chemical vapor deposition (CCVD) with acetylene as the carbon source and iron oxide as the catalyst. The spatial concentration distribution of amorphous carbon (which produces the carbon nanotubes) is obtained by solving the system of governing equations for the momentum, energy and mass transport during CNT formation, using COMSOL Software. The temperature and velocity distributions in the reactor were also obtained from the analysis. The results obtained from the analysis are useful for the optimal design of the CVD furnace.

Graphene-polymer nanocomposites have attracted considerable attention due to their unique properties, such as high thermal conductivity (~3000 W mK^-1), mechanical stiffness (~ 1 TPa) and electronic transport properties. Relatively, the thermal performance of graphene-polymer composites has not been well investigated. The major technical challenge is to understand the interfacial thermal transport between graphene nanofiller and polymer matrix at small material length scale. To this end, we conducted molecular dynamics simulations to investigate the thermal transport in graphene-polyethylene nanocomposite. The influence of functionalization with hydrocarbon chains on the interfacial thermal conductivity was studied, taking into account of the effects of model size and thermal conductivity of graphene. The results are considered to contribute to development of new graphene-polymer nanocomposites with tailored thermal properties.

We have simulated a photovoltaic (PV) pn junction where a texturing structure from Silicon nanowires (NWs) is added. While the NWs diameter was kept constant at a value of 100 nm, their lengths were varied over the range from 1 μm to 100 μm. A noticeable enhancement in the device efficiency is found. This improvement is due to that the added texture has significantly decreased the optical reflectance and increased the optical absorption of the surface.

Nowadays, the hemodialytic treatment of patients with either acute or chronic renal failure has been improved by promoting biocompatibility in the use of new materials and improve membrane surface characteristics. Low and high flux polysulfone membranes (PM) used in dialysis and ultra filtration have been studied in order to understand the geometry and surface chemistry of the pores at inner (nanometric) and outer (micrometric) membrane parts. The surface changes of polysulfone cartridge membrane (PM) during different number of consecutive reuse trials: after 1^st, 10^th and 23^th times of use. The morphology of the hollow fibers surfaces was studied by means of the atomic force microscopy (AFM) imaging and the surface roughness analysis. The roughness of both inner and outer part of PM surface increases with numbers of reuse trails. Thus, small and medium size pores were wiped out when the number of uses changed from zero to 23 on the outer surface. The pore density decreases. The inner part of membrane shows some nanometric size deformation in forms of new openings and raptures. The AFM analysis show differences in the PM morphology at the nanometric level, not previously revealed, which could be important in the evaluation of the PM.

Recently published experimental evidence shows that nano-silica is a material that can be used to enhance the strength and durability characteristics of concrete. Engineered concrete at the nano-scale is achieved through the integration of nano-materials in suitable proportions and relevant mixing methods. Being a pozzolanic and reactive material along with nucleation effects and miniature particle size, nano-silica has been found to significantly improve the micro-structural characteristics of concrete making it denser and more uniform. The ongoing research work at the University of Melbourne is based on a novel modelling approach to further investigate the performance characteristics of nano-silica on cement paste at the micro-meter scale. The volumetric proportions of different phases present in concrete are computed considering hydration characteristics of cement and those of nanosilica. A Representative Volume Element (RVE) of the cement paste at micro scale is developed considering the hydrated gel as the matrix material while other phases present are integrated as randomly distributed spherical particles. Constitutive material models for these phases are assumed. The stress-strain relationship for the RVE is then generated using COMSOL Multiphysics software. The approach proposed in this paper is an initiation towards developing an acute and compressive model to predict the performance characteristics of nano-engineered concrete.

In order to eliminate limitations of existing experimental or computational methods (such as patch-clamp technique or molecular dynamic analysis) a finite element (FE) model for multi length-scale and time-scale investigation on the gating mechanism of mechanosensitive (MS) ion channels has been established. Gating force value (from typical patch clamping values) needed to activate Prokaryotic MS ion channels was applied as tensional force to the FE model of the lipid bilayer. Making use of the FE results, we have discussed the effects of the geometrical and the material properties of the Escherichia coli MscL mechanosensitive ion channel opening in relation to the membrane’s Young’s modulus (which will vary depending on the cell type or cholesterol density in an artificial membrane surrounding the MscL ion channel). The FE model has shown that when the cell membrane stiffens the required channel activation force increases considerably. This is in agreement with experimental results taken from the literature. In addition, the present study quantifies the relationship between the membrane stress distribution around a ‘hole’ for modeling purposes and the stress concentration in the place transmembrane proteins attached to the hole by applying an appropriate mesh refinement as well as well defining contact condition in these areas.

Tactic heat resistant polymer was prepared by free radical polymerization of lactic acid-based monomers, i.e. chiral 2-isopropyl-5-methylene-1,3-dioxolan-4-ones (1). The polymerization of 1 proceeded smoothly without ring-opening to give a polymer with high isotacticity (mm) of 29.7~100% and glass transition temperature (T_g) of 172~213°C. 1 also showed high reactivity in the copolymerization with styrene and methyl methacrylate, and the incorporation of 1 unit in the copolymer structure increased T_g of each polymer. In addition, hydrolysis of poly(1) produced a new type of water soluble poly(lactic acid), i.e. poly(α-hydroxy acrylate), and poly(α-hydroxy acrylate-co-divinyl benzene) hydrogel absorbed water as high as 1000 times of the original polymer weight.

We present a thick magneto-optical metal sandwiched between two dielectric magnetophotonic crystals of enhancing Faraday rotation effect. It is found that the transmission and Faraday rotation effect can simultaneously be enhanced when impedance and phase matching conditions are satisfied in the sandwiched. Moreover, the Faraday rotation of a double peak and a single peak is studied in sandwiched structure, respectively.

The mechanical properties of carbon fiber reinforced resin composites (CFRP) including the epoxy matrix, the carbon fiber and the interface of the carbon fiber/epoxy composites were investigated by means of nanoindentation technique. The hardness, Young’s modulus of the components in CFRP were obtained. The results show that the hardness and Young’s modulus have a gradient variation from the epoxy matrix to carbon fiber.

We investigated single-walled carbon nanotubes (SWNT) and DNA-SWNT hybrids by atomic force microscopy (AFM). From the AFM observation of several different types of SWNTs and DNA-SWNT hybrids in air, we found several specific differences in morphology among the samples. Longer SWNT molecules were observed when the SWNT was dispersed using a bath type sonicator. When a probe type sonicator was used, the SWNT became short obviously. The phenomenon was common in all of our experiments, thus, the phenomenon was independent on the types SWNTs. SWNT functionalized with polyethyleneglycol (PEG SWNT), amino group (NH₂ SWNT), and carboxyl group (COOH SWNT) showed individual specific features in AFM images. Although NH₂ SWNT is typically soluble in organic solvents, uniform distribution was observed when DNA molecules were mixed with NH₂ SWNT. Finally, we observed DNA-SWNT hybrids by AFM in liquids for the first time. DNA-SWNT hybrids were significantly swollen in the aqueous solution even though the sample was dried once. This is helpful information for considering biological applications of the DNA-SWNT hybrids.

In the notebook and clamshell mobile phone, data communication wire often requires repeated bending. Generally, communication wire with the actual application conditions, the test data cannot assess bending resistance performance of data communication wire is tested conventionally using wires with weights of 90 degree to test bending number, this test method and device is not fully reflect the fatigue performance in high frequency and light load application condition, at the same time it has a large difference between the test data of the long-term reliability of high frequency and low load conditions. In this paper, high frequency light load fatigue testing machine based on the giant magnetostrictive material and stroke multiplier is put forward, in which internal reflux stroke multiplier is driven by giant magnetostrictive material to realize the rapid movement of light load. This fatigue testing device has the following advantages: (1) When the load is far less than the friction, reducing friction is very effective to improve the device performance. Because the body is symmetrical, the friction loss of radial does not exist in theory, so the stress situation of mechanism is good with high transmission efficiency and long service life. (2) The installation position of the output hydraulic cylinder, can be arranged conveniently as ordinary cylinder. (3) Reciprocating frequency, displacement and speed of high frequency movement can be programmed easily to change with higher position precision. (4)Hydraulic oil in this device is closed to transmit, which does not produce any environment pollution. The device has no hydraulic pump and tank, and less energy conversion processes, so it is with the trend of green manufacturing.

Fixed abrasive polishing technology can obtain a nanoscale surface and is one of the future nano machining directions. The coefficient of friction between the pad and the wafer in the polishing process can influence on the surface quality of the wafer. The relationship between the coefficient of friction and surface roughness of the wafer was investigated to improve the efficiency and surface quality. Based on the Florida model, the adhesion, asperity plough and abrasive plough from the pad in the polishing process was analyzed. The friction force per unit area was calculated by the properties of the pad and wafer. Based on the rod model, the actual contact area was calculated by the surface roughness and the properties of the pad and wafer. The relational model between the surface roughness of the wafer and the friction coefficient was established. The model was verified by the experiments of fixed abrasive polishing of BK7 glass. When the friction coefficient is less than 1.9, the data of the experiment and theory match very well in the comparison process.

A multi-channeled filter based on the effect of light-tunneling through the coupled Fabry–Perot (FP) cavity resonators is proposed. The wall of FP cavity is composed of the single-negative metamateiral. Applying the transfer matrix method we analyze the transmission mechanism of the filter. By introducing the coupled FP cavity resonators at the optical and microwave frequency ranges respectively, the single resonant mode is split into some discrete resonant peaks, leading to the multichanneled filtering phenomenon. In comparison with the conventional multichanneled filters, the proposed structure is more compact and tunable. The microwave experiment results are found in agreement with simulation results.

In this study, aerosol deposition of nanoparticles on flat surfaces has been investigated by Langevin dynamics (LD) accounting for Brownian’s diffusion and a fix translational velocity. The particles are assumed to drop one at a time and had a monodisperse size distribution. The detailed morphology of the nanoparticle films was investigated as a function of Pe number, the ratio between Brownian and translational displacement for different structural constrains. The porosity was reduced with increasing Pe number from the diffusion to ballistic deposition limit. It was found that the simulation constrains have a substantial impact on the resulting film structural properties. This was attributed to the multi-scale porosity of these aerosol-deposited films.

In this study, a novel approach using low-load cyclic compression fatigue technique to gradually propagate cracks in a brittle porous material and enhance fluid flow in a controlled direction was investigated. The technical feasibility of using this technique to increase permeability was evaluated by conducting cyclic fatigue, hydraulic conductivity, and crack formation tests. It was shown that this technique could be used to gradually propagate crack(s) in a controlled direction, and increase permeability in a porous and brittle material. The method improves the conventional counterpart of hydraulic fracture by inducing controlled damage formations, without suddenly compromising the structural integrity of the material, thereby manipulating permeability. The highest permeability recorded is approximately 4.25 × 10^-9 m/s for 1,000 fatigue cycles. The results have implications for enhancing the capabilities of liquid CO₂ sequestration in deep sea sediments.