Semi-auxetic piezoresistive textronic.

Auxetic textile sensors represent a new generation of wearable sensors, offering advantages such as high sensitivity, enhanced mechanical properties, and greater comfort due to their suitable physical features. Research in this field remains limited and is still in its nascent stages. In this work, a piezoresistive sensor with a negative Poisson's ratio was developed using the design concept of semi-auxetic yarn, where a stretchable band replaced the core to serve as a substrate for the piezoresistive sensors. A semi-auxetic piezoresistive textronic structure was created by stitching the sensors onto the substrate in a zig-zag pattern. Electromechanical analysis highlighted a trade-off between auxetic behaviour and sensitivity, with the highest sensitivity (-4.8) observed in a structure with a stitching length of 2 cm, and the highest auxeticity (-14.1) found in a structure with a stitching length of 3 cm. This type of piezoresistive textronic is suitable for applications such as yoga straps, driving safety belts, compression bandages, and breathable belly belts for pregnant women.