Plastic Deformation in a Molecular Crystal Enables a Piezoresistive Response

Small. 2023 Mar;19(12):e2206169. doi: 10.1002/smll.202206169. Epub 2023 Jan 1.

Abstract

Organic materials are promising candidates for the development of efficient sensors for many medicinal and materials science applications. Single crystals of a small molecule, 4-trifluoromethyl phenyl isothiocyanate (4CFNCS), exhibit plastic deformation when bent, twisted, or coiled. Synchrotron micro-focus X-ray diffraction mapping of the bent region of the crystal confirms the mechanism of deformation. The crystals are incorporated into a flexible piezoresistive sensor using a composite constituting PEDOT: PSS/4CFNCS, which shows an impressive performance at high-pressure ranges (sensitivity 0.08 kPa-1 above 44 kPa).

Keywords: crystals; devices; piezoresistance; plastic flexibility; supramolecular.