Development of textile-based strain sensing material by bar-coating technique

With advent of 5G technology, the collection and analysis of physiological data such as limb movement are propelled by Internet of Things (IoT) devices. The wearable textiles have the capability to sense the movement of limbs. In this work, a strain sensing material was developed by employing bar coating technique and using a combination of multi-walled carbon nanotubes (MWCNT), polydimethylsiloxane (PDMS) nanocomposite paste and polyester angle-interlocked knitted fabric. Thus produced textile-based strain sensing material was characterized for piezoresistive properties for up to 20% strain. The measurements revealed remarkable differences in electrical conductivity and strain sensing property along the two principal directions of the knitted fabric. Also, the thermal properties of the strain sensing material were characterized through thermogravimetric analysis along with temperature dependency (from 40 to 80 °C). The least temperature-dependent material was found to be a nanocomposite paste made up of 5% MWCNT. To ensure a proper coating of nanocomposite layer, a specific proportion of the solvent was maintained. Because of this, the higher MWCNT content materials led to form agglomerations that resulted in deviations from the normal trend in both piezoresistive and thermal responses.