Pressure Sensors Painted on Flexible Cellulose Substrates from Polyaniline-Based Conductive Ink

Abstract

Electrically conductive inks based on polyaniline (PANI) have been prepared using phytic acid as a cross-linking agent. The resistive response of these inks at low vacuum pressure has been reported in this article. The polyaniline phytic acid (PPA) ink is mixed with SnO2 and graphite flakes to form tin oxide-incorporated polyaniline phytic acid (PPAS) and graphite-incorporated polyaniline phytic acid (PPAG) ink systems, respectively. The inks have been used to paint on cellulose substrates to obtain flexible electronic materials. X-ray diffractometry measurements confirm that the prepared ink systems (PPA, PPAS, and PPAG) are crystalline in nature. Surface morphology and molecular structures are confirmed by scanning electron microscopy, UV–vis–NIR spectroscopy, and Fourier transform infrared spectroscopy, which reveal the formation of a 3D structure of the molecules, reasonably supported by phytic acid having six anionic phosphate groups per molecule. The mechanism governing the charge transport phenomenon has been discussed based on the electrical and optical properties of the prepared inks. The experimental results demonstrate that the flexible, use-and-throw vacuum pressure sensor based on cellulose substrates can be a promising candidate for chemical processing, gas delivery manifolds, and wearable circuitry in artificial intelligence.