Effect of the Surface Roughness on the Detecting Capacitance

With the MEMS technology advancement, electronic devices are miniaturized at every development node. The surface roughness is affecting the detecting capacitance of MEMS device because surface to volume ratio is increasing rapidly. A novel model with one rough electrode is investigated in this paper. The impacts of surface roughness on detecting capacitance are analyzed. The image of height percentage is used to describe the surface roughness of electrode sample. The function of the surface roughness is obtained according the method of curve fitting. The effect of surface roughness on the capacitance is calculated. The results demonstrate the capacitance increases with the surface roughness.

Effect of Anode Surface Roughness on Power Generation in Microbial Fuel Cells

A three-electrode system was used to study the effect of anode surface roughness on the performance of microbial fuel cells (MFCs). Two glassy carbon plates were polished to uniform roughness of the orders of magnitude of 10s of nm and 100s of nm. Atomic force microscopy (AFM) was used to quantify the roughness as well as the 3D topography of the surfaces. Multiple electrochemical methods including potentiostatic tests, potentiodynamic tests, and electrochemical impedance spectroscopy (EIS) were utilized to monitor the performance of the glassy carbon electrodes. After 275 hours of experimentation, the current density generated by the rough electrode was much higher than that generated by the smooth one. Furthermore, the charge-transfer resistance of the rough electrode was lower than that of the smooth one. The better electrochemical performance of the rough surface may be due to denser biofilm grown on the surface, which was observed by scanning electron microscopy (SEM).