HIGH STRAIN AND BIOCOMPATIBLE SCREEN PRINTED NANOCOMPOSITE BASED CONDUCTIVE PDMS STRAIN SENSORS

Abstract

Strain sensors capable of operating in high strain conditions remain a technical challenge.In particular, biocompatible strain sensor technology is needed that satisfies the following requirements: (1) construction from low modulus materials that approach values of soft biological tissues and (2) high strain operation (≥ 20%).We present a screen printed, nanocomposite-based conductive polydimethylsiloxane (CPDMS) strain sensor capable of 40% strain operation with a gauge factor (GF) >100.Strain sensing using CPDMS sensors containing multi-walled carbon nanotubes (MWNT), graphene nanoplatelets (GNP), or a mixture of both nanocarbon filler materials was demonstrated.The combination of high strain operation, high GF, and biocompatible construction pave the way for minimally invasive in vivo strain measurements.Strain sensors were characterized according to their conductivity, zero current resistance (ZCR), thermal coefficients of resistance (TCR), and gauge factor.