Breathing measurement on the basis of contact resistance of cross-overlapping conductive yarns

To improve the comfort and conformance of the textile-integrated breathing sensor, the change of contact electrical resistance of cross-overlapping conductive yarns was utilized to make piezo-resistive sensors, and the tape with this simple sensor was used to record human respiratory signal. And also, it was explored for the methods enhancing the electromechanical responses. The experimental results indicated that an increasing number of contact points improved the change of contact resistance. Furthermore, the coated silica gel at the contact points helps to avoid the slippage of overlapping threads under tensile strain and to improve the repeatability of the electro-mechanical responses. The in-time sampled human breathing signal at rest demonstrated the performance of the developed textile sensor. These results showed that the developed simple and portable sensor possesses good sensitivity and linearity under low dynamic forces, and the relocation of the cross-overlapping yarns leads to the poor repeatability and stability of piezoresistive textile sensors.