A MEMS based electrochemical seismometer with a novel integrated sensing unit

Abstract
This study proposed a new process to fabricate the sensing unit of an electrochemical seismometer using only one silicon wafer. Based on this new fabrication process, the effective area of electrodes and the fabrication efficiency were significantly improved. In this study, the SU-8 negative photoresist was utilized as both the substrate (exposed SU-8) and the sacrificial layer (unexposed SU-8) on top of which the suspended platinum electrodes were fabricated using the positive-photoresist lift-off technology. The performances of the proposed devices were characterized experimentally where compared to the commercially available counterpart CME6011, significant improvements in 3 dB working bandwidth (0.11 Hz ~21.50 Hz vs. 0.47 Hz ~18.24 Hz) and device sensitivity (1592V/(m/s) vs. 820 V/(m/s)) were located.