TENG, Shock sensing, Vibration sensing, MEMS low-frequency switch, Self-powered, Energy harvester
Triboelectric-nano-generator (TENG) is able to produce a very small current and a large voltage compared to piezoelectric or electromagnetic generators. The large voltages from the TENGs are suitable for operating MEMS devices without external AC or DC generators. Producing micro-sized TENG using MEMS fabrication process enables integration of them with MEMS sensors and actuators. This combination is useful because the required voltage for driving MEMS is obtained from the motion of the event that is being measured. In this work, an event-driven vibration sensor is introduced which actuates a switch as the frequency or amplitude of the vibration exceeds a desired threshold. Using CMOS micromachining, a 1.5 mm × 1.5 mm TENG in contact-separation (CS) mode is fabricated to convert ambient vibrations to a voltage generated between a conductive aluminum layer and a dielectric Polyimide layer. The large generated voltage between the electrodes can operate a low-frequency electrostatic MEMS switch. Two events are able to produce the resonant dynamic pull-in needed to close the switch. Event one is when the input amplitude exceeds the dynamic pull-in threshold which is called acceleration sensitive mode. Event two is when the frequency of the vibration exceeds a specified threshold. An electromechanical model for the MEMS switch part of the vibration sensor is also presented. Results show that MEMS-TENG is able to supply the MEMS switch in the frequency sensitive and acceleration sensitive modes with a good signal-to-noise-ratio, sensitivity, and accuracy.
The final version of this article is published in Mechanical Systems and Signal Processing.
Mousavi, Mohammad; Alzgool, Mohammad; Davaji, Benyamin; and Towfighian, Shahrzad, "Event-driven MEMS vibration sensor: Integration of triboelectric nanogenerator and low-frequency switch" (2023). Mechanical Engineering Faculty Scholarship. 43.
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