How to Make Elastomers Piezoelectric?

Piezoelectrics play a significant role in modern electronics and electric devices. Thermal or mechanical stress on such materials induces a change in polarization generating an electric response, which is the sole effect of why they are so interesting. However, most piezoelectrics are rigid and brittle ceramics and thus difficult to integrate into wearable electronics that comply with human skin or organs. To facilitate their incorporation into stretchable, so-called next generation electronic devices, researchers have focused on developing piezoelectric materials with improved properties. Significant advances are achieved regarding flexibility. However, marrying piezoelectricity and elasticity proved challenging, as elastomers, with their amorphous flexible network structure, cannot keep polarization permanently. Here the most recent developments in the field of piezoelectric elastomers are reviewed, and potential future applications in sensors and energy harvesting are discussed.