Design and Fabrication of a Pillar-Based Piezoelectric Microphone Exploiting 3D-Printing Technology

This letter presents a 3-D-printed piezoelectric microphone with enhanced voltage sensitivity. The sensitivity is improved by a combination of a single-pillar mechanical design and a specific polyvinylidene fluoride (PVDF)-film electrode patterning. The moving part of the mechanical structure and the chassis are 3D-printed as a single unit and trimmed by laser cutting, allowing for a simple fabrication of the device. The measured sensitivity of 1 mV/Pa (±6 dB) in the bandwidth 500-2500 Hz agrees with simulations, showing an improvement over similar pillar-based piezoelectric sensor solutions. The sensitivity performance is shown to be comparable to existing microphones with different technologies. The microphone is also characterized by excellent linearity within the measurable range. 3D-printing technique can thus be adopted for the manufacturing of low cost and highly customizable microphone sensors.