Sensing performance of knitted strain sensor on two-dimensional and three-dimensional surfaces
Yutian Li, Xuhong Miao, Jonathan Y. Chen, Gaoming Jiang, Qing Liu
Abstract
Flexible strain sensors and their sensing performance have been attractive in human motion detection applications. In this project, a knitted strain sensor was designed and fabricated via the technology of weft-knitting a nylon/nylon-wrapped spandex/silver-coated yarn into a knitted garment. Locations of sensor areas were customized to form a whole piece of knitted garment popular for today's applications in elastic tight-fitting activewear. The sensor provides electrical resistance data as a wearable sensing device for detecting body motions. A new method of using a three-dimensional curved surface to evaluate the sensing performance of the knitted strain sensor was proposed. Compared with the method of two-dimensional test, the three-dimensional test method was closer to the actual human sensing situation when the knitted sensor is worn. The strain sensing range of the three-dimensional curved surface was 120%, twice the sensing range of the two-dimensional surface. This research indicated that this three-dimensional surface testing method could be effectively applied in the sensing performance evaluation of fabric strain sensors.