Scalable Manufacturing of Amino Acid-Based Piezoelectric Biocrystal Films

Glycine is a promising piezoelectric biocrystal owing to its excellent biocompatibility, strong piezoelectric response, and high crystallinity. Recent discovery of polymer-directed crystallization of glycine in an aqueous environment offers the feasibility for continuous manufacturing of this biocrystal film at the industry-relevant level. In this paper, we report continuous production of glycine-PVA piezoelectric biocrystal thin films by adapting a commercial polymer manufacturing apparatus with a uniform sandwiched microstructure. By tuning the feeding rate and solvent evaporation dynamics, a stable crystallization front is maintained, enabling continuous film growth over lengths of tens of centimeters, which largely matches a numerical kinetic model. The as-produced films exhibit sandwiched microstructure, with uniform thickness, grain size, and piezoelectric coefficient across the entire area. Fifty-six piezoelectric nanogenerator devices were fabricated on a single large-scale film, demonstrating the feasibility of high-throughput device production. This work establishes a stable and industrially viable strategy for the large-scale manufacturing of piezoelectric biocrystal films, offering significant potential for mass production of biocompatible piezoelectric devices.