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Silicon carbide (SiC) was synthesized from Vietnamese rice husk and diatomite by electric arc discharge furnace with the arc current of 100, 150, and 200 A. The synthesized products were characterized by Raman spectroscopy, XRD, FE-SEM, and EDS. The result showed that α-SiC material with the purity of up to 85.12 % had been successfully synthesized from Vietnamese diatomite and rice husk charcoal. Also, there is remained amount of carbon and SiO2 which can be removed by burning and leaching processes.

In this paper, we report on a SOI-based comb capacitive-type accelerometer that senses acceleration in two lateral directions. The structure of the accelerometer was designed using a proof mass connected by four folded-beam springs, which are compliant to inertial displacement causing by attached acceleration in the two lateral directions. At the same time, the folded-beam springs enabled to suppress cross-talk causing by mechanical coupling from parasitic vibration modes. The differential capacitor sense structure was employed to eliminate common mode effects. The design of gap between comb fingers was also analyzed to find an optimally sensing comb electrode structure. The design of the accelerometer was carried out using the finite element analysis. The fabrication of the device was based on SOI-micromachining. The characteristics of the accelerometer have been investigated by a fully differential capacitive bridge interface using a sub-fF switched-capacitor integrator circuit. The sensitivities of the accelerometer in the two lateral directions were determined to be 6 and 5.5 fF/g, respectively. The cross-axis sensitivities of the accelerometer were less than 5%, which shows that the accelerometer can be used for measuring precisely acceleration in the two lateral directions. The accelerometer operates linearly in the range of investigated acceleration from 0 to 4g. The proposed accelerometer is expected for low-g applications.

This paper illustrates both thermal and mechanical analysis methods for displacement and contact force calculating of a novel sensing silicon-polymer microgripper when heat sources are applied by an electric current via its actuators. Thermal analysis is used to obtain temperature profile by figuring out a heat conductions and convections model. Temperature profile is then applied into the mechanical structure of the gripper's actuators to form the final equation of displacement and contact force of the jaws. Finally, the comparison among the calculation, simulation and actual measurement concludes that materialization methods are appropriate. Achieving the final equation of gripper's jaws displacement and contact force is a major step to optimize or reform this novel structure for different sizes to meet specific applications.

This paper reports on the design and fabrication of a z-axis tuning fork gyroscope which has a freestanding architecture. In order to improve the performance of the tuning fork gyroscope by eliminating the influence of the squeeze-film air damping, the driving and sensing parts of the gyroscope were designed to oscillate in-plane. Furthermore, by removing the substrate underneath the device, the slide-film air damping in the gap between the proof masses and the substrate was eliminated. The proposed architecture was analyzed by the finite element method using ANSYS software. The simulated frequencies of the driving and sensing modes were 9.788 and 9.761 kHz, respectively. The gyroscope was fabricated using bulk micromachining technology. The quality factor and sensitivity of the gyroscope operating in atmospheric conditions were measured to be 111.2 and 11.56 mV/°/s, respectively.