Eggshell protein modified cotton fabric for flexible and sustainable piezoelectric wearable sensors

Abstract

As potential alternatives for traditional rigid piezoelectric materials, fabric-based piezoelectric nanogenerators with environmentally friendly, biocompatible and high-performance bio-based piezoelectric materials show great potential for applications in health monitoring, artificial intelligence and electronic skin. As one of the abundant natural piezoelectric materials, eggshell membranes have attracted great attention in piezoelectric sensing and energy harvesting due to their renewability, environmentally friendly nature and biocompatibility. Herein, a flexible fabric-based piezoelectric sensor with an enhanced piezoelectric output is constructed with the incorporation of soluble eggshell membrane protein (SEP). The hydrogen bonds formed by the abundant amino/amide functional groups on the surface of SEP and the hydroxyl groups of cellulose are conducive to the interfacial interaction with cotton fibers, which promotes the solid adsorption of SEP and improves the mechanical properties of the composites. The highest piezoelectric output of ∼1.3 V is produced when the SEP content is 1 wt%, which is approximately eight times that of the pristine cotton fabric. In addition, the flexible piezoelectric sensor is successfully applied for human motion detection, pronunciation recognition, and human–machine interaction. Given the scalability and ease of fabrication, this work provides a new research approach for the preparation of green, flexible and high-performance electronic devices.