Design and Development of Polyaniline-coated Fabric Strain Sensor for Goniometry Applications

Abstract

In the last few years, the smart textile area has become increasingly widespread, leading to developments in new wearable sensing systems. As conventional sensor techniques often cause problems for long term patient monitoring (e.g. skin irritation, hampering wires), elegant solutions are explored to integrate sensors in clothing. By using the textile material itself as a sensor, the integration is increased resulting in even more patient friendliness. In this paper, a flexible fabric strain sensor with high sensitivity, good stability and large deformation is reported. It is fabricated by in-situ polymerization of polyaniline on the fabric substrate at low temperature. Thickness and morphology of the conducting thin film on the surface of the fibers were examined by scanning electron microscopy (SEM). The resistivity of the PANi coated fabric was measured using standard two probe apparatus. The measurement of the conductivity change with strain shows that the fabrics so prepared exhibits a high strain sensitivity while its good stability is indicated by a small loss of conductivity after the thermal and humidity aging tests, and supported by the slight change in conductivity over storage of 90 days. The developed flexible strain sensor can be used in the preparation of smart garment for goniometry applications.