Ferro-electret nanogenerators as flexible microphones

Research on flexible transducers capable of sensing acoustic signals has become increasingly important due to its implications in human interfaces with wearable electronics. The proof-of-concept for a flexible microphone/loudspeaker based on the use of a ferro-electret nanogenerator (FENG) was recently presented. Following that, this work characterizes FENG-based microphones, showing the sensitivity of a 5 cm × 5 cm, single layer FENG to be ~ .015 mV/Pa. The variance of sensitivity based on surface area is also studied and presented. Polar patterns or directivity is emphasized in this work by studying how various shapes (i.e. flat, concave and convex) affect the output. The spectral information of the output of FENG-based microphone to typical voice input is compared with a commercially available microphone.