2021 article

Inkjet Printed Textile Force Sensitive Resistors for Wearable and Healthcare Devices

Ju, B., Kim, I., Li, B. M., Knowles, C. G., Mills, A., Grace, L., & Jur, J. S. (2021, July 1). ADVANCED HEALTHCARE MATERIALS.

By: B. Ju n, I. Kim n, B. Li n, C. Knowles n, A. Mills n , L. Grace n, J. Jur n

co-author countries: United States of America πŸ‡ΊπŸ‡Έ
author keywords: E-textiles; flexible electronics; force sensitive resistors; inkjet printing; piezoresistive sensors; wearable healthcare devices
MeSH headings : Delivery of Health Care; Electric Conductivity; Electrodes; Humans; Textiles; Wearable Electronic Devices
Source: Web Of Science
Added: July 12, 2021

Pressure sensors for wearable healthcare devices, particularly force sensitive resistors (FSRs) are widely used to monitor physiological signals and human motions. However, current FSRs are not suitable for integration into wearable platforms. This work presents a novel technique for developing textile FSRs (TFSRs) using a combination of inkjet printing of metal-organic decomposition silver inks and heat pressing for facile integration into textiles. The insulating void by a thermoplastic polyurethane (TPU) membrane between the top and bottom textile electrodes creates an architectured piezoresistive structure. The structure functions as a simple logic switch where under a threshold pressure the electrodes make contact to create conductive paths (on-state) and without pressure return to the prior insulated condition (off-state). The TFSR can be controlled by arranging the number of layers and hole diameters of the TPU spacer to specify a wide range of activation pressures from 4.9 kPa to 7.1 MPa. For a use-case scenario in wearable healthcare technologies, the TFSR connected with a readout circuit and a mobile app shows highly stable signal acquisition from finger movement. According to the on/off state of the TFSR with LED bulbs by different weights, it can be utilized as a textile switch showing tactile feedback.