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The purpose of this paper is to propose an alternative approach to improve the performance of microelectromechanical systems (MEMSs) silicon (Si) condenser microphones in terms of operating frequency and sensitivity through the introduction of a secondary material with a contrast of mechanical properties in the corrugated membrane.

Finite element method from COMSOL is used to analyze the MEMS microphones performance consisting of solid mechanic, electrostatic and thermoviscous acoustic interfaces. Hence, the simulated results could described the physical mechanism of the MEMS microphones, especially in the case of microphones with complex geometry. A 2-D model was used to simplify computation by applying axis symmetry condition.

The simulation results have suggested that the operating frequency range of the microphone could be extended to be operated beyond 20 kHz in the audible frequency range. The data showed that the frequency resonance of the microphone using a corrugated Si membrane with SiC as the embedded membrane is increased up to 70 kHz compared with 63 kHz for the plane Si membrane, whereas the microphone’s sensitivity is slightly decreased to −79 from −76 dB. Furthermore, the frequency resonance of a corrugated membrane microphone could be improved from 26 to 70 kHz by embedding the SiC material. Last, the sensitivity and frequency resonance value of the microphones could be modified by adjusting the height of the embedded material.

Based on these theoretical results, the proposed modification highlighted the advantages of simultaneous modifications of frequency and sensitivity that could extend the applications of sound and acoustic detections in the ultrasonic spectrum with an acceptable performance compared with the typical state-of-the-art Si condenser microphones.

The purpose of this paper is to visualize protein manipulation using dielectrophoresis (DEP) as a substantial perspective on being an effective protein analysis and biosensor method as DEP is able to be used as a means for manipulation, fractionation, pre-concentration and separation. This research aims to quantify DEP using an electrochemical technique known as cyclic voltammetry (CV), as albumin is non-visible without any fluorescent probe or dye.

The principles of DEP were generated by an electric field on tapered DEP microelectrodes. The principle of CV was analysed using different concentrations of albumin on a screen-printed carbon electrode. Using preliminary data from both DEP and CV methods as a future prospect for the integration of both techniques to do electrical quantification of DEP forces.

The size of the albumin is known to be 0.027 µm. Engineered polystyrene particle of size 0.05 µm was selected to mimic the DEP actuation of albumin. Positive DEP of the sample engineered polystyrene particle was able to be visualized clearly at 10 MHz supplied with 20 Vpp. However, negative DEP was not able to be visualized because of the limitation of the apparatus. However, albumin was not able to be visualized under the fluorescent microscope because of its translucent properties. Thus, a method of electrical quantification known as the CV technique is used. The detection of bovine serum albumin (BSA) using the CV method is successful. As the concentration of BSA increases, the peak current obtained from the voltammogram decreases. The peak current can be an indicator of DEP response as it correlates to the adsorption of the protein onto the electrodes. The importance of the results from both CV and DEP shows that the integration of both techniques is possible.

The integration of both methods could give rise to a new technique with precision to be implemented into the dialyzers used in renal haemodialysis treatment for manipulation and sensing of protein albumin.