Effect of Fabric Structure on the Performance of 3D Woven Pressure Sensor

The textile-based pressure sensors are an integral part of the wearable electronic textiles, that helps to measure the pressure/load applied to the sensor. These sensors are used predominantly for health and sports application, especially to monitor the blood pressure, heart rate or performance of muscles during exercise. The work done in this research is about the investigation of the response of a 3D woven fabric-based pressure sensor by varying the yarn interlacement pattern in 3 layered fabric. Four samples were produced using a 3D weaving technique, with two types of yarns i.e. polyester/cotton (59 tex) and multifilament steel (55.5 tex). The weave design of face and back layer of the three-layered structure was kept 1/1 plain (P), while the weave design of middle layer was changed to plain (P), matt (M), twill (T) or satin (S), resulting in structures PPP, PMP, PTP, and PSP respectively. Working of pressure sensor was evaluated in terms of resistance offered by structure, both under static and dynamic loading. The dynamic load was applied by the compression and subsequent relaxation, i.e. under incremental loading followed by decremental unloading. All the structures showed variation in resistance in response to applied load showing potential being used as a pressure sensor. The structures PPP, PMP, and PSP behaved as a pressure sensor up to 500 grams while the efficient sensor was PTP (plain/twill/plain) with activity up to a load of 5500 grams. A statistical model was developed for the structure PTP, correlating the resistance with the applied load. The developed sensors can also be produced inside the fabrics or can be embedded inside garments.