Metal-Free Enantiomeric Organic Crystals for Piezoelectric Energy Harvesting

The power source material applied in wearable electronic
devices
should be soft, flexible, stretchable, and biocompatible. Organic
piezoelectric materials, with their unique combination of these properties,
show great promise as innovative energy-harvesting materials. Herein,
we present an enantiomeric organic piezoelectric material, R/S-MP-TFSA (MP = 2-Methylpiperazine, TFSA
= Trifluoromethanesulfonimide), which crystallizes at room temperature
in the polar space group P1 and exhibits a pronounced
second-harmonic generation (SHG) response. With a piezoelectric coefficient
(d33) of 20 pC/N, the R/S-MP-TFSA- based piezoelectric device demonstrates
a stable piezoelectric output voltage of approximately 16 V under
simple finger-tapping conditions, a representative example of human
mechanical motion. These characteristics highlight its considerable
potential for applications in piezoelectric sensors for energy harvesting
and self-powered low-voltage electronic devices.