MEMS PZT Oscillating Platform for Fine Dust Particle Removal at Resonance

Micro-electromechanical systems (MEMS) sensors designed to sense fine particles on the surface apply electrical signals to identify the corresponding physical changes on the surface. These sensors have limitations when the accumulated fine particles saturate the measurement range. In this study, we have studied how to effectively remove the accumulated particles after detection, rather than measuring the sensing performance. In general, MEMS sensors are used to detect fine particles in a high frequency region for higher resolution. However, in this work, we fabricated an oscillating platform that could be driven at a relatively low frequency region (< MHz), which the high sensing resonance. As an example of fine particles, fine dust having a diameter of 1 to 10 mm was used. The fabricated lead zirconate titanate (PZT) piezoelectric oscillating platform had a resonant frequency of 424.1 kHz, with a sensitivity of 934.2 nm/V at the resonance point. This oscillating platform was able to effectively provide sufficient acceleration to remove the dust from the surface when subjected to resonance. We have predicted the minimum required voltage to remove the particles based on van der Waals force theory, and the measured sensitivity (nm/V) of the oscillator. These values agreed to the experimentally measured voltages when the dust particles started to detach from the surface. To completely remove all the particles from the surface, the applied voltage had to be doubled.