This study focuses on the design, simulation, fabrication, and test of the in-plane microgenerator to obtain a high-power output. The microgenerator comprises multilayer planar silver (Ag) microcoil of low-temperature cofired ceramics (LTCC) and multipole hard magnet of Nd/Fe/B (neodymium, iron, and boron). The LTCC process is an approach that saves costs and time to fabricate the microcoil. The multipole hard magnet of Nd/Fe/B provides the large magnetic energy product to contribute to the power. Finite element simulations have been carried out using COMSOL Multiphysics® to observe electromagnetic information. The induced voltages of coils in different basic geometric shapes, including square-shaped coils, circle-shaped coils, and sector-shaped coils, are simulated separately in this study. A prototype of the microgenerator is <1 cm3 in volume size. The simulated result can be compared to the experimental one. The results of simulation reveal that this microgenerator with a sector-shaped microcoil generates a maximum effective value of the induced voltage of 232.7 mV and the power of 2.5 mW. And the 1-µm gap between the microcoil and the magnet achieved is the value that is mentioned above. Experimental measurement shows close agreement with finite element simulations.
The existing research on interface properties between heterogeneous materials mainly focuses on semiconductor-metal and dielectric materials, but little on organic-inorganic ones. In recent years, the nanoscale phenomena related to the mechanical properties of organic/inorganic material interfaces is gaining a lot of attention and becoming a new area of nanorelated research. Since gold (Au) exhibits excellent optical, electrical, and mechanical properties, it can be applied to nanooptics, mechanics, and electronics. This study explores the nano effect of the mechanical properties between the interface of Au and heterologous polymethyl methacrylate (PMMA) with different side groups, i.e., isotactic-PMMA, syndiotactic-PMMA, and atactic-PMMA. These heterologous PMMA thin films are prepared using a spin-coater to deposit the different side groups of PMMA upon Au thin film. A sputter technique is used to form Au thin films with different thicknesses. An indenter probe is applied by adding different forces on its tip into the PMMA and Au thin films to realize the interface mechanical properties such as hardness and Young's modulus. Finally, the time-dependent properties of viscoelastic materials are evaluated by using this harmonic nanoindentation test.
The left ventricular (LV) wall motion is the most challenging and interesting task in cardiac evaluation. In this paper, an integrated system that measures and displays left ventricular wall motion is presented. Based on the 3D reconstruction of ventricle from nine rotational cross- sectional images acquired with multiplane transesophageal echocardiography (TEE), a quantitative and visual expression of the motion of LV is presented. Nine images were obtained with the transducer rotating around a central axis passing through LV. A sequence of image processing operations have been developed for detecting left ventricular boundaries from TEE images obtained with different angle in a whole cardiac cycle. The algorithm which integrates 2D boundary information into 3D volume representation is designed based on automata theory. The phantom study for computing the scaling factors between the image metrics and the physical metrics shows a good correlation between the computed results and the specimens in the in vitro study. Finally, the 3D shape visualization of the reconstructed moving ventricle is presented. The performance of proposed experiments shows good feasibility of the new application of TEE in cardiac evaluation.