Glycine-based Flexible Biocompatible Piezoelectric Pressure Sensor for Healthcare Applications

This work presents biocompatible flexible piezoelectric composite fabricated by self-assembly of amino acid glycine molecules inside natural chitosan polymer. Piezoelectric composite film consists of glycine spherulite structure embedded in chitosan matrix. The x-ray diffraction confirms the crystallization of stable $\beta$-glycine inside the composite and hence its piezoelectric nature. As a result, a simple solvent-casting technique have been used to fabricate the biodegradable composite of $\beta$-glycine/chitosan with significant piezoelectric response. We show that the piezoelectric sensor can precisely measure pressure in the range of 0-40 kPa with sensitivity of $\sim 4.7$ mV kPa$^{-1}$. The devices based on bio-based functional material such as glycine offer huge potential for disposable wearable health applications such as monitoring the pressure in a compression bandage.