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This paper presents the first-of-its-kind electrochemical seismic sensor where, a liquid proof mass (e.g., electrolyte solution) was used as the sensing element to translate environmental vibrations into active ion imbalances between electrodes, and therefore producing electrical current outputs. Theoretical analysis and numerical simulations were conducted to confirm the feasibility of the device concept and the proposed micro seismic sensor was fabricated by conventional MEMS technologies. Device characterization based on a vibration table recorded a linear relationship between applied velocities and output voltage amplitudes with a calculated sensitivity of 274 V/(m/s) (20–80 Hz). The performance of the proposed micro device was compared with a commercially available macro counterpart (MET2003), indicating strong correlations of these two types of devices in response to random vibrations while the proposed micro seismic sensor was capable of producing a lower power spectrum compared to MET2003. In summary, the electrochemical micro seismic sensor developed in this study is featured with mass fabrication capabilities due to MEMS technologies, comparable performance and lower power spectrum compared to conventional electrochemical seismometers. This newly developed micro sensor can be potentially used in the field of seismology, enabling the ground motion monitoring to locate earthquakes, volcanic eruptions, and other seismic sources.

This paper presents a micro-electro-mechanical system (MEMS) based electrochemical seismic sensor where insulating spacers and sensing electrodes were contained in a plexiglass tube filled with an ion-rich electrolyte solution. Sensing electrodes and insulation spacers were fabricated based on MEMS processes and assembled by adhesive bonding in a layer-by-layer manner. The device performance was first characterized in a customized experimental platform, with a quantified bandwidth of 0.2-5 Hz and a linear voltage output as a function of the input vibration amplitude. A random-vibration testing in the laboratory environment was conducted, where response correlations among seven devices were calculated as 0.976±0.017, suggesting high device repeatability. This newly proposed seismic sensor may function as a promising seismic motion detecting device in the field of geophysical prospecting where low-frequency seismic motion detection is requested.

This paper presents a first-of-its-kind electrochemical seismic sensor based on MEMS technologies. The electrochemical seismic sensor consists of electrodes immersed in electrolyte solution. The output current of the sensor is employed to measure the ground motion.The new design of interdigital electrodes solves the misalignment problem of conventional counterparts and reduces the self-noise. This device is featured with simple structure, low cost, mass fabrication as well as comparable performance verified by experimental results.