Unmet NeedPiezoelectricity in biopolymers has attracted considerable attention from the scientific community due to biopolymers’ well-defined structure and inducible permanent polarity. Piezoelectric films are used in a number of medical and practical applications, such as ultrasounds and microphones. Current films typically use polyglutamate, a biopolymer that only exhibits piezoelectricity in shear mode (denoted as d
14). In other words, the polymer only exhibits a polar charge if the electric field is applied perpendicular to the poling field. In addition, the poling setup required for polyglutamate is cumbersome and expensive, creating a need for an alternate method for polarizing films.
Technology OverviewThis technology is a fabrication process that utilizes a novel biopolymer with high piezoelectric coefficients and thermal stability to make a polar film that can be used in modern day devices. The fabrication process allows production of poled helical biopolymer films that exhibit piezoelectricity in all modes (d
33, d
31, d
14). In addition, the film’s piezoelectric coefficient does not deteriorate when sustained at temperatures higher than 100°C for more than 24 hours (existing biopolymer films start to lose piezoelectric activity at temperatures above 80°C). The fabrication process uses electrospinning and hot press, which are simple, scalable, and cost-effective alternatives to the orthodox poling setup. Compared to other biopolymer films, this material is easy and inexpensive to fabricate and exhibits superior thermal stability and polarity.
Stage of DevelopmentA working prototype has been produced and detailed in published papers
