Polymer-nanoparticle composite foams for energy harvesting applications

Throughout the course of one day, the human body goes through numerous mechanical activities. These activities, while usually not very powerful individually, produce an ample amount of energy collectively. This mechanical energy can be harvested into electrical energy via piezoelectricity. Recent research into piezoelectric nanocomposites has yielded techniques to foam the materials into softer, porous structures more suitable for human comfort. This study focuses on using a host polymer polydimethylsiloxane (PDMS) and citric acid to create foams. Citric acid, a common industrial chemical blowing agent (CBA), is used in this project due to its capabilities to produce foams with consistent pore sizes and distribution. These foams, coupled with piezoelectric nanoparticles, are fabricated, analyze, and tested. They are mechanically characterized using tensile testing. Electrical characterization is carried out using an integrated mechanical-electrical testing setup. These foams are lighter, softer, and can produce higher electrical output than nonporous counterparts. We believe that these foams have great potential in upcoming piezoelectric technology.