This PDF file contains the front matter associated with SPIE Proceedings Volume 7975, including the Title Page, Copyright information, Table of Contents, Introduction, and the Conference Committee listing.

Insects are dependant on the spatial, spectral and temporal distributions of light in the environment for flight control and navigation. This paper reports on flight trials of implementations of insect inspired behaviors on unmanned aerial vehicles. Optical flow methods for maintaining a constant height above ground and a constant course have been demonstrated to provide navigation capabilities that are impossible using conventional avionics sensors. Precision control of height above ground and ground course were achieved over long distances. Other vision based techniques demonstrated include a biomimetic stabilization sensor that uses the ultraviolet and green bands of the spectrum, and a sky polarization compass. Both of these sensors were tested over long trajectories in different directions, in each case showing performance similar to low cost inertial heading and attitude systems. The behaviors demonstrate some of the core functionality found in the lower levels of the sensorimotor system of flying insects and shows promise for more integrated solutions in the future.

The sensitivity and selectivity of insect antennae are evolutionary tuned to specific needs of the insect. The Australian pyrophilic beetle Merimna atrata needs freshly heated wood to bring up its offspring and, consequently, shows a very high sensitivity to volatiles specific for wood-fires and heated wood. Volatile organic compounds released by wood particles heated at different temperatures were collected. Parallel trace analytical examination and antennal responses of the pyrophilic beetles to volatiles released by the wood reveal a highly differentiated detection system of these insects for early and late products of wood fires. This enabled a selection of marker compounds used by insects since several million years for the discrimination of different stages of wood fires. In the industrial production of engineered wood such as particle boards, wooden particles are dried in large-scale high temperature dryers. Air temperatures between 150-600°C are essential for the required material flow in the particle board production. Despite the resulting energy-efficiency of high temperature drying, high temperatures are avoided because of the increased risk of spontaneous combustion. Losses in productivity caused by fire have a strong impact on the whole production system. In order to raise the drying temperature without risking a fire, it is important to develop a monitoring system that will reliably detect early fire stages by their characteristic volatile pattern. Thus, perception filters and evaluation algorithms of pyrophilic insects can provide blue prints for biomimetic gas sensors for large-scale drying of wood particles. Especially tungsten oxide sensor elements exhibit a high sensitivity to some of the key substances. Their high sensitivity and selectivity to terpenes and aldehydes in combination with high sensitivity and selectivity of tin oxide sensor elements to hydroxylated and phenolic compounds, both showing low cross-reactivity with water and carbon monoxide, mimic highly efficient biological fire detection systems.

Beetles of the genus Melanophila and certain flat bugs of the genus Aradus approach forest fires. For the detection of fires and of hot surfaces the pyrophilous species of both genera have developed infrared (IR) receptors, which have developed from common hair mechanoreceptors. Thus this type of insect IR receptor has been termed photomechanic and shows the following two special features: (i) the formation of a complex cuticular sphere consisting of an outer exocuticular shell as well as of a cavernous microfluidic core. (ii) The enclosure of the dendritic tip of a mechanosensitive neuron inside the core in a liquid-filled chamber. Most probably a photomechanic IR sensillum acts as a microfluidic converter of infrared radiation into an increase in internal pressure inside the sphere, which is measured by a mechanosensitive neuron. A simple model for this biological IR sensor is the Golay sensor, which is filled with a liquid instead of gas. Here the absorbed IR radiation results in a pressure increase of the liquid and the deflection of a thin membrane. For the evaluation of this model analytical formulas are presented, which permits the calculation of the pressure increase in the cavity, the deformation of the membrane and the time constant of an artificial leak to compensate ambient temperature changes. Some organic liquids with high thermal expansion coefficients may improve the deflection of the membrane compared to water.

The lateral line system of fish is important for many behaviors, including spatial orientation, prey detection, shoaling, intra specific communication and entraining. The smallest sensory unit of the lateral line is the neuromast that occurs free standing on the skin and in fluid filled canals. With aid of the lateral line fish perceive minute water motions. In their natural habitat fish are not only faced with biotic water motion but also with the abiotic fluctuations caused by various inanimate sources. The detection of meaningful signals is crucial for survival, and therefore animals should be able to separate meaningful signals from noise. Fishes live in various habitats (e.g. in still water or in running water). Therefore it is not surprising that the number and distribution of neuromasts as well as canal dimension, canal shape and canal branching patterns differ among fish species. We studied how lateral line canal parameters influence the filter properties of lateral line canals. To do so we exposed artificial lateral line canals, equipped with artificial neuromasts (sensors), to the vortex street shed by a submerged cylinder and to air bubble noise. We found that certain canal parameters significantly can enhance the signal to noise ratio.

Musca domestica, the common house fly, possesses a powerful vision system that exhibits features such as fast, analog, parallel operation and motion hyperacuity -- the ability to detect the movement of objects at far better resolution than predicted by their photoreceptor spacing. Researchers at the Wyoming Information, Signal Processing, and Robotics (WISPR) Laboratory have investigated these features for over a decade to develop an analog sensor inspired by the fly. Research efforts have been divided into electrophysiology; mathematical, optical and MATLAB based sensor modeling; physical sensor development; and applications. This paper will provide an in depth review of recent key results in some of these areas including development of a multiple, light adapting cartridge based sensor constructed on both a planar and co-planar surface using off-the-shelf components. Both a photodiode-based approach and a fiber based sensor will be discussed. Applications in UAV obstacle avoidance, long term building monitoring and autonomous robot navigation are also discussed.

A gel-supported lipid bilayer formed at the base of an artificial hair is used as the transduction element in a membrane-based artificial haircell sensor inspired by the structure and function of mammalian outer hair cells. This paper describes the initial fabrication and characterization of a bioderived, soft-material alternative to previous artificial haircells that used the transduction properties of synthetic materials for flow and touch sensing. Under an applied air flow, the artificial hair structure vibrates, triggering a picoamp-level electrical current across the bilayer. Experimental analysis of this mechanoelectrical transduction process supports the hypothesis that the oscillating current is produced by a time-varying change in the capacitance of the membrane caused by the vibration of the hair. Specifically, frequency analysis of both the motion of the hair and the measured current show that both phenomena occur at similar frequencies, which suggests that changes in capacitance occur as a result of membrane bending during excitation.

Self-oscillating hydrogels driven by the Belousov-Zhabotinsky (BZ) reaction provide a unique foundation for the mimicry of autonomic biological systems. One of the key challenges for assessing practical performance limits of these materials is detailed knowledge of the chemical and mechanical characteristics of the BZ gels at various states of autonomic behavior. Recently we developed two BZ gel systems based on gelatin and polyacrylamide. The desired chemical response for effective swelling-deswelling oscillation and mechanical force production involves a delicate balance of chemical wave period, amplitude, and gel swelling properties. The chemical performance of gelatin and polyacrylamide BZ gels according to this criteria is discussed.

Insect cuticle has a broad range of mechanical properties. As it has to provide a very efficient and lightweight skeleton, cuticle is a highly interesting composite-material and may serve as a natural model for new biomimetic materials. However, the water content of insect cuticle is of great importance for its material properties. Here, we present a new method to perform nano-indentation experiments in cuticle which has its full water content. Parts of the exoskeleton of Locusta migratoria were investigated to determine the elastic modulus (Er) and hardness (H) of the cuticle. Cuticle sections were measured in air and then submerged and measured in water. As insect cuticle is an anisotropic material, we performed nano-indentation in the normal as well as in the transverse direction and also tested different cuticle layers within each sample (exo-, meso- and endo-cuticle). It turned out that a change of the water content has a dramatic impact on the material properties of the cuticle. For example, the Er of submerged endo-cuticle turned out to be 75% lower than of endo-cuticle samples measured in air. Further, the proportion of material property values between different cuticle layers within a sample change dramatically after addition of water.

Bio-inspired assembly of platelet particles and polyelectrolytes into ordered layered nanocomposites, which mimic the brick-and-mortar nanostructure found in the nacreous layer of mollusk shells, is of great technological importance in developing light-weight reinforced materials, separation membranes, and gas-barrier coatings. Unfortunately, the widely utilized layer-by-layer self-assembly technology is tedious in creating thick multilayered coatings. Here we report a simple filtration technology that enables the scalable production of inorganic nanoplatelets-polymer nanocomposites with layered structures. Water suspended montmorillonite (MTM) nanoclay platelets are pre-mixed with polyvinyl alcohol (PVA) aqueous solution to make stable colloidal suspensions. By using a simple vacuum filtration setup, ordered layered MTM nanoclay-PVA nanocomposites with controlled thickness can be easily prepared. The resulting selfstanding films exhibit higher tensile strength and toughness than those of natural inorganic-organic nanocomposites including nacre, bone, and dentin.

This paper presents a fully coupled multi-scale finite element model for the description of the dissipative mechanical response of wood cell walls under large strains. Results show the ability of the present model to capture the main phenomenological responses found typically in wood at the microscopic scale. In addition, the structural and mechanical concepts involved in wood cells are exploited further in order to design new wood inspired composites. Numerical tests are conducted in prototypes of bio-inspired composites and demonstrate substantial gains in terms of resistance to failure and in the control of the overall flexibility/stiffness balance in the material.

Spider orb webs are known to produce colour displays in nature, both in reflection and transmission of sunlight, under certain illumination conditions. The cause of these colours has been the subject of speculation since the time of Newton. It has also been the topic of observational interpretation and some experiment which has proposed diffraction by the fine silks, scattering from rough/structured surfaces and thin film effects as the primary causes. We report systematic studies carried out using the silks of Australian orb web weaving spiders. Studies of both white light and laser light scattering/propagation by natural spider silks have definitively determined the primary cause of the colour displays is rainbows that can be understood by the application of geometric optics combined with new knowledge of the optical properties of the spider web strands, silks, and proteins as optical materials. Additionally, a range of microscopies (optical, AFM, optical surface profiling) show the silks to be optically flat. Overall, spider silks emerge as fascinating optical materials with high dispersion, high birefringence and the potential for future research to show they have high nonlinear optical coefficients. Their importance as a bioinspiration in optics is only just beginning to be realised. Their special optical properties have been achieved by ~136 million years of evolution driven by the need for the web to evade detection by insect prey.

A silicon prismatic lens, whose shape is inspired by the apposition compound eyes of some dipterans, was investigated to improve the light-harvesting capability of silicon solar cells. The bioinspired compound lens (BCL) has a fractal construction procedure in which the cross-section of the lens is a frustum of a infinitely long circular cylinder at the zeroth-stage, and is decorated with sections of smaller cylinders at higher stages of construction. We found that the light-coupling efficiency of the best performing first-stage BCL cannot be enhanced by higher-order stages and is significantly superior to other kinds of textured surfaces. By coating the lens with a double layer anti-reflection coating further enhancement of efficiency can be obtained. Our strategy can also be adopted for solar cells not made of silicon.

The study of Tobacco hawkmoths, Manduca sexta, with respect to the relationships between muscle activation and flight response has progressed to a point that closed loop heading control is possible on the live, tethered animals. We present a method of control through stimulation of the dorsoventral muscle (DVM) groups that are responsible for the upward motion of the wings. An experimental setup allowing for only yaw in flying moths was developed. A 10% duty cycle square wave input was used to stimulate the DVM on the side of the moth inboard of the desired turn. Both continuous and discontinuous signals were used and the results suggest that the moth is able to compensate for consistent input stimulation.

This paper presents the development of a bioinspired flight control system and a characterization of its performance when operating in turbulent and gusting airflow conditions. This design consists of a skeletal structure with a network of feather-like panels installed on the upper and lower surfaces, extending beyond the trailing edge. Each feather is able to deform into and out of the boundary layer, thus permitting local airflow manipulation. The gust load sensing is predominately performed near the leading edge of the airfoil, and the reaction forces are generated by the feathers located at the trailing edge. For this study, the focus presents a benchmark case of the NACA 4412 airfoil with the standard 20% trailing edge flap design operating in a gusting, turbulent airflow. COMSOL Multiphysics is used to model the flow field and the fluid-structure interactions using Direct Numerical Simulation. The dynamics of the gusting model are developed using MATLAB and LiveLink connected to COMSOL to enable unsteady, turbulent simulations to be performed. Discrete and continuous gusts are simulated at various airfoil angles of attack. Additionally, the airfoils' aerodynamic performance is comparatively analyzed between time-varying and steady-state turbulence models. This paper discusses how these two-dimensional, time-varying turbulent and gusting airflow simulation results can be developed and integrated into a LQR closed-loop feed back flight control system.

Barn owls are specialists in prey detection using acoustic information. The flight apparatus of this bird of prey is most efficiently adapted to the hunting behavior by reducing flight noise. An understanding of the underlying mechanisms owls make use of could help minimize the noise disturbances in airport or wind power plant neighborhood. Here, we characterize wings of barn owls in terms of an airfoil as a role model for studying silent flight. This characterization includes surface and edge specialization (serrations, fringes) evolved by the owl. Furthermore, we point towards possible adaptations of either noise suppression or air flow control that might be an inspiration for the construction of modern aircraft. Three-dimensional imaging techniques such as surface digitizing, computed tomography and confocal laser scanning microscopy were used to investigate the wings and feathers in high spatial resolution. We show that wings of barn owls are huge in relation to their body mass resulting in a very low wing loading which in turn enables a slow flight and an increased maneuverability. Profiles of the wing are highly cambered and anteriorly thickened, especially at the proximal wing, leading to high lift production during flight. However, wind tunnel experiments showed that the air flow tends to separate at such wing configurations, especially at low-speed flight. Barn owls compensated this problem by evolving surface and edge modifications that stabilize the air flow. A quantitative three-dimensionally characterization of some of these structures is presented.

By combining the modified conformal-evaporated-film-by-rotation (M-CEFR) technique with nickel electroforming, we have produced master negatives of nonplanar biotemplates. An approximately 250-nm-thick conformal coating of nanocrystaline nickel is deposited on a surface structure of interest found in class Insecta, and the coating is then reinforced with a roughly 60-μm-thick structural layer of nickel by electroforming. This structural layer endows the M-CEFR coating with the mechanical robustness necessary for casting or stamping multiple polymer replicas of the biotemplate. We have made master negatives of blowfly corneas, beetle elytrons, and butterfly wings.

In architecture, shell construction is used for the most efficient, large spatial structures. Until now the use of wood rather played a marginal role, implementing those examples of architecture, although this material offers manifold advantages, especially against the background of accelerating shortage of resources and increasing requirements concerning the energy balance. Regarding the implementation of shells, nature offers a wide range of suggestions. The focus of the examinations is on the shells of marine plankton, especially of diatoms, whose richness in species promises the discovery of entirely new construction principles. The project is targeting at transferring advantageous features of these organisms on industrial produced, modular wood shell structures. Currently a transfer of these structures in CAD - models is taking place, helping to perform stress analysis by computational methods. Micro as well as macro structures are the subject of diverse consideration, allowing to draw the necessary conclusions for an architectural design. The insights of these tests are the basis for the development of physical models on different scales, which are used to verify the different approaches. Another important aim which is promoted in the project is to enhance the competitiveness of timber construction. Downsizing of the prefabricated structural elements leads to considerable lower transportation costs as abnormal loads can be avoided as far as possible and means of transportation can be loaded with higher efficiency so that an important contribution to the sustainability in the field of architecture can also be made.

Ionomeric Polymer Metal Composite (IPMC) actuators generate high flexural strains at small voltage amplitudes of 2-5V. IPMCs bend toward the anode when a potential drop is applied across its thickness. The actuation mechanism is due to the motion of ions inside it; which requires a form of hydration to dissociate and mobilize the charges. In our group IPMCs are developed either water based or Ionic Liquid based which is also known as the dry IPMCs. This combination of small voltage requirement with operation in both dry and underwater conditions makes the IPMCs a viable alternative for an Autonomous Jellyfish Vehicle (AJV). In this study, we estimate the mechanical properties of IPMC actuator having curved geometry using FEM model to match the experimental deformation. We combine the results from an electric model to estimate charge accumulated on electrode surface with piezoelectric model to estimate stress due to this charge accumulation. In the last step, the results are integrated with a structural model to simulate the actuator deformation. We have designed an AJV with embedded IPMC actuators using these properties to achieve the curvature of relaxed and contracted Jellyfish (Aurelia Aurita). Bio-mimetic deformation profile was achieved by using structural mechanics of beams with large deformation with only application of +/- 0.8V to optimized beam within 8.1% error norm in relaxed state and 21.3% in contracted state, with only -0.24% to 0.26% maximum flexural strain at maximum curvature point in contracted state.

In this paper, we present a wireless powering system for Ionic Polymer Metal Composites (IPMCs). The need for technological advancements towards the realization of hovering flight and swimming in biological systems motivates the system design. We demonstrate IPMC wireless powering through radio frequency magnetically coupled coils and ad hoc power electronics for low frequency IPMC actuation. We identify the parameters of the circuit components describing the resonantly coupled coils. We analyze the power transfer from the external power source to the receiver at the IPMC and compare the actuation performance of the IPMC in the wireless and wired configurations.

As bone has piezoelectric properties, it is expected that activity of bone cells and bone formation can be accelerated by applying piezoelectric ceramics to implants. Since lead ions, included in ordinary piezoelectric ceramics, are harmful, a barium titanate (BTO) ceramic, which is a lead-free piezoelectric ceramic, was used in this study. The purpose of this study was to investigate piezoelectric effects of surface charge of BTO on cell differentiation under dynamic loading in vitro. Rat bone marrow cells seeded on surfaces of BTO ceramics were cultured in culture medium supplemented with dexamethasone, β-glycerophosphate and ascorbic acid while a dynamic load was applied to the BTO ceramics. After 10 days of cultivation, the cell layer and synthesized matrix on the BTO surfaces were scraped off, and then DNA content, alkaline phosphtase (ALP) activity and calcium content were measured, to evaluate osteogenic differentiation. ALP activity on the charged BTO surface was slightly higher than that on the non-charged BTO surface. The amount of calcium on the charged BTO surface was also higher than that on the non-charged BTO surface. These results showed that the electric charged BTO surface accelerated osteogenesis.

Bilayers are synthetically made cell membranes that are used to study cell membrane properties and make functional devices that incorporate inherent properties of the cell membranes. Lipids and proteins are two of the main components of a cell membrane. Lipids provide the structure of the membrane in the form of two leaflets or layers that are held together by the amphiphilic interaction between the lipids and water. Proteins are made from a combination of amino acids and the properties of these proteins are dependent on the amino acid sequence. Some proteins are antibiotics and can easily self insert into the membrane of a cell or into a synthetically formed bilayer. The peptide alamethicin is one such antibiotic that easily inserts into a bilayer and changes the conductance properties of the bilayer. Analytical models of the conductance change with respect to the potential and other variables across the bilayer follows the nonlinear conductance changes seen with the incorporation of the peptide in a bilayer. The individual channels formed by the peptide have been studied and the peptide has several discrete conductance levels. These discrete levels have been shown to be dependent on the potential across the bilayer and several other variables including the lipid variety. The conductance level for a single channel can change with time in a probabilistic fashion. This paper will model these discrete conductance levels of the peptide alamethicin and the model of the single channel conductance will be used to model the cumulative effect of multiple channels within a bilayer.

Some think that using derivatives of snake venom for medical purposes is the modern version of snake oil but they are seriously misjudging the research potentials of some of these toxins in medicines of the 2000's. Medical trials, using some of the compounds has proven their usefulness. Several venoms have shown the possibilities that could lead to anticoagulants, helpful in heart disease. The blood clotting protein from the taipan snake has been shown to rapidly stop excessive bleeding. The venom from the copperhead may hold an answer to breast cancer. The Malaysian pit viper shows promise in breaking blood clots. Cobra venom may hold keys to finding cures for Parkinson's disease and Alzheimer's. Rattlesnake proteins from certain species have produced blood pressure medicines. Besides snake venoms, venom from the South American dart frog, mollusks (i.e. Cone Shell Snail), lizards (i.e. Gila Monster & Komodo Dragon), some species of spiders and tarantulas, Cephalopods, mammals (i.e. Platypus & Shrews), fish (i.e. sting rays, stone fish, puffer fish, blue bottle fish & box jelly fish), intertidal marine animals (echinoderms)(i.e. Crown of Thorn Star Fish & Flower Urchin) and the Honeybee are being investigated for potential medical benefits.

The majority of double-acting hydraulic cylinders are controlled via a 4/3 spool valve, which allows for the active movement of the cylinder in two directions, as well as holding its current position. These control valves lack the ability to "dangle," or rather, the ability to permit the hydraulic cylinder to freely sway passively in response to external forces. Including the ability to dangle within a control valve is of particular interest for a number of reasons. It allows for much more naturalistic actuation of the hydraulic cylinder, making it further compatible with bio-inspired platforms, such as driving the legs of a prosthetic limb or an exoskeleton for human augmentation. Additionally, dangle offers an opportunity for considerable efficiency gains. This is possible because the momentum of the load, gravity, among other external forces, can be utilized to move the actuator instead of solely relying on an active input. A novel control valve that integrates all of the features of a 4/3 spool valve in addition to dangle is reported herein.

There have been many attempts to enhance heat transfer during the condensation (vapor to liquid) process since condensation is a critical heat transfer mechanism in many industrial processes. One conventional method of enhancing condensation heat transfer is to specially treat the condensing heat exchanger surface to adequately promote so-called "dropwise" condensation. Biomimetically constructed coating with hydrophobic materials is often employed for surface treatment. This coating on the condensing heat transfer surface effectively shifts the condensation mode from filmwise (the conventional heat transfer mode) to dropwise (similar to lotus leaves?), resulting in much higher condensation heat transfer. In this method the thickness of coatings is a key parameter governing the heat transfer rate. Thin coating benefits the heat transfer but can lead to weakening hydrophobicity and failure to have an acceptable life span. However, thick coating reduces or eliminates the merit of the dropwise condensation phenomenon because the coating introduces additional thermal resistance. Herein, we report an innovative biomimetic concept in connection with a surface treatment that potentially solves the aforementioned issues. Instead of using conventional dense coatings on the condensing surface, the concept of randomly arranged or structurally oriented nano or submicro-scale fins and/or porous surfaces similar to nature-invented hydrophobic surfaces allowing molecular clustering for effective steam condensation, is presented and experimentally verified.

The phenomenon of surface wettability has been a contested issue in phase change heat transfer applications. Its research area has previously broadened in scope from microscale into nanoscale structured surfaces with the aid of high-end techniques such as nanoelectromechanical system (NEMS) and microelectromechanical system (MEMS). However, those techniques are both expensive and time-consuming in creating practical nanoscale-structures. In this study, we propose a streamlined technique to create tunable ultrahydrophobic/philic self-assembled copper oxide nanostructures with multiple tier roughness. Using a bottom-up process, a fast fabrication time can be achieved (relative to NEMS and MEMS) through our simple, cost-effective bulk fabrication technique. As demonstrated through the present experiments, we can control the surface wettability by introducing morphological adaptivity.

During their nocturnal activity period, weakly electric fish employ a process called "active electrolocation" for navigation and object detection. They discharge an electric organ in their tail, which emits electrical current pulses, called electric organ discharges (EOD). Local EODs are sensed by arrays of electroreceptors in the fish's skin, which respond to modulations of the signal caused by nearby objects. Fish thus gain information about the size, shape, complex impedance and distance of objects. Inspired by these remarkable capabilities, we have designed technical sensor systems which employ active electrolocation to detect and analyse the walls of small, fluid filled pipes. Our sensor systems emit pulsed electrical signals into the conducting medium and simultaneously sense local current densities with an array of electrodes. Sensors can be designed which (i) analyse the tube wall, (ii) detect and localize material faults, (iii) identify wall inclusions or objects blocking the tube (iv) and find leakages. Here, we present first experiments and FEM simulations on the optimal sensor arrangement for different types of sensor systems and different types of tubes. In addition, different methods for sensor read-out and signal processing are compared. Our biomimetic sensor systems promise to be relatively insensitive to environmental disturbances such as heat, pressure, turbidity or muddiness. They could be used in a wide range of tubes and pipes including water pipes, hydraulic systems, and biological systems. Medical applications include catheter based sensors which inspect blood vessels, urethras and similar ducts in the human body.

Spitting cobras defend themselves by ejecting rapid jets of venom through their fangs towards the face of an offender. To generate these jets, the venom delivery system of spitting cobras has some unique adaptations, such as prominent ridges on the surface of the venom channel. We examined the fluid acceleration mechanisms in three spitting cobra species of the genus Naja. To investigate the liquid-flow through the venom channel we built a three-dimensional 60:1 scale model. First we determined the three-dimensional structure of the channel by using microcomputer tomography. With help of the micro computer tomographical data we then created a negative form out of wax. Finally, silicon was casted around the wax form and the wax removed, resulting in a completely transparent model of the cobra´s venom channel. The physical-chemical properties of the cobra venom were measured by micro rheometry and tensiometry. Thereafter, an artificial fluid with similar properties was generated. Particle image velocimetry (PIV) was performed to visualize the flow of the artificial liquid in the three-dimensional model. Our experiments show how the surface structure of the venom channel determines the liquid flow through the channel and ultimately the form of the liquid jet. Understanding the biological mechanisms of venom ejection helps to enhance industrial processes such as water jet cutting and cleaning as well as injection methods in technical and medical sectors, e.g. liquid microjet dissection in microsurgery.

As UAVs and sensor networks become ubiquitous, cost and accuracy will be increasingly traded. We have developed techniques for calibration that consider this problem. Our technique performs a nonlinear optimization through all variables associated with zeroth and first order affects on accuracy of the sensors. The optimization is constrained by the known properties of the magnetic and gravitational fields. A miniature autopilot is presented as an example of the pressing need for automation of calibration.

We report on an optical device to aid landing of Unmanned Aerial Systems. Optical flow calculates a measure of observed angular movement of the image seen by the sensor. Optical flow can be converted to range if speed of the sensor is known. Our approach eliminates this requirement by using two optical flow sensors displaced vertically to calculate range. The initial implementation was tested on an instrumented UAV with promising results. We show that the sensor provides useful range measurements at a height of several meters. We argue that this technique is comparable to vision techniques such as stereo in this application. We show alternate implementations with optics that do not require vertical displacement.

This work is concerned with the dynamics of motor proteins. In particular, we discuss the development of computational analysis tools for predicting the dynamics of molecular motors such as certain types of kinesin. The ability to model and predict how these biomolecular machines work forms the critical link to biotechnological device development, including lab-on-a-chip applications and many others. The focus of this research is on the identification and modeling of nonlinear dynamic phenomena caused by coupled thermal, chemical, and mechanical fields. A mechanistic model of kinesin has been developed recently at the University of Michigan. This model accounts for transient dynamics and uses parameters which have to be identified from experimental data and/or from first principles. In this work, accurate atomistic simulations using a monomeric human kinesin structure (PDB ID: 1MKJ, 2.70 Angstroms resolution) is used instead of experimental data to obtain key nano-scale properties of the motor protein. The approach allows an accurate bridging between nano-scale processes occurring over pico seconds and micron- or millimeter-scale processes occurring over seconds.

Adhesive organs enable insects to cling to various substrates. During locomotion, a very fast but reliable change of adhesion and detachment is realised. To reveal the detailed underlying mechanisms of this impressive performance, we analysed the ultrastructure of adhesive organs of the stick insect C. morosus using scanning electron microscopy (SEM), transmission electron microscopy (TEM) and confocal laser scanning microscopy (CLSM).

The sandfish (Scincidae: Scincus scincus) is a lizard having the remarkable ability to move through desert sand in a swimming-like fashion. The most outstanding adaptation to its subterranean life is the epidermis that shows low friction behaviour and extensive abrasion resistance against sand, outperforming even steel. The skin consists of glycosylated keratins, which were found to be absolutely necessary for the described phenomenon. Here we discuss the function of serrated microstructures found upon dorsal scales of the sandfish by comparing them with a closely related, non-sandswimming skink (Scincopus fasciatus) and resin replicas. Furthermore, we investigated further functions of these serrations, like infrared- and moisture harvesting and the prevention of triboelectric charges. We further provide a pathway towards exploitation the sandfish's skin abilities for future engineering applications.