Piezoelectric PDMS films for power MEMS

Abstract

We have successfully demonstrated the fabrication of piezoelectric PDMS films utilizing casting, stacking, and micro plasma discharge processes. To realize electromechanical sensitivity, PDMS structures with micrometer-sized cells are implanted with positive and negative charges on the opposite internal surfaces of each cell, which behaves just like a dipole. In the prototype demonstration, multilayer PDMS films with inner cells of 50×50×50 μm 3 are fabricated and charged under electric fields up to 40 MV/m. The resulting cellular PDMS films show an elastic modulus of at least 12% lower than solid ones and a piezoelectric coefficient (d 33 ) up to 182 pC/N, which is about 10 times higher than that of common piezoelectric polymers (e.g., PVDF). As such, the demonstrated piezoelectric PDMS films could serve as soft and sensitive electromechanical transducers, which are desired for a variety of sensor and energy har-vesting applications.

Sacrificial Water-Soluble BaO Layer for Fabricating Free-Standing Piezoelectric Membranes

“…We note that the capacitor structure formed by the PDMS films may also generate a voltage response upon bending. − It has been reported that if a 10 kV poling voltage is applied to induce local dipoles in a PDMS layer, PDMS may exhibit a piezoelectric coefficient d 33 of 350 pC/N. In contrast, our BaTiO 3 devices involve no poling because the BaTiO 3 layer is intrinsically polar.…”