Fabrication of Ag/PDMS-TiO2 flexible piezoresistive pressure sensor

Abstract

In this study, TiO2 nanorods are grown on a flexible Polydimethylsiloxane (PDMS) substrate using the hydrothermal technique. The morphological, structural, compositional, optical properties and pressure sensing are investigated in detail by FESEM, XRD, EDX, UV–visible spectrophotometer, and piezoelectric studies. XRD demonstrates the pure rutile phase with a tetragonal structure is formed from deposited TiO2 thin film. FESEM images confirm the TiO2 nanorods with average dimensions length ~620 nm and diameter ~97 nm whereas the optical spectrum shows the strong light absorption in the UV region with bandgap 3.54 eV. The voltage is measured as a response to the applied mechanical load and the sensitivity of the pressure sensor is obtained as 2.56 × 10−5 V/N. The flexible pressure sensors (Ag/PDMS-TiO2) senses over a large pressure range and shows a linear response because of the adjustments in the volume of dielectric that makes the pressure inside the dielectric cavity to vary. © 2020 Elsevier B.V.