Princeton and CalTech have developed a way of printing piezoelectric elements onto rubber so that they generate current when the rubber moves. This allows breakthroughs in implantable or wearable energy harvesting systems where the motion of the person powers the electronics, particularly low energy sensors.
Being electromechanically coupled, piezoelectric crystals represent a particularly interesting subset of smart materials that function as sensors/actuators, bioMEMS devices, and energy converters. Yet, the crystallization of these materials generally requires high temperatures for maximally efficient performance, rendering them incompatible with temperature-sensitive plastics and rubbers. The researchers have overcome these limitations by presenting a scalable and parallel process for transferring crystalline piezoelectric nanothick ribbons of lead zirconate titanate from host substrates onto flexible rubbers over macroscopic areas.