Combining electronics on flexible plastic strips with textiles

Electronic textiles are an enabling technology for a variety of applications in health care, rehabilitation or sports. In this paper, three methods to combine flexible plastic strips with textiles are discussed. Flexible plastic strips serve as carriers for electronic devices. The first approach uses a roving frame to wrap flexible plastic strips with cotton fibers. For the second method, flexible plastic strips are woven into textiles using a narrow fabric loom and a rapier loom. In the third approach, flexible plastic strips are embroidered on a shuttle embroidery machine. Due to the flexible plastic strips, electronic devices mounted on the strips are exposed to strain with the potential to damage the electronics. For the three presented methods, strain on the surface of a flexible plastic strip is investigated: roving causes strain >25%, embroidery approximately 6% and weaving 15%. Weaving flexible plastic strips is investigated in more detail because it offers possibilities to embed thin-film devices, surface mount devices and integrated circuits into textiles. Conductive yarns within the textile are used to contact the electronics. Weaving flexible plastic strips is first applied to fabricate a textile patch with woven flexible plastic strips carrying thin-film temperature sensors. In a second textile patch, a flexible plastic strip carrying an accelerometer is woven in the weft direction and connected with conductive yarns in the warp direction. The textile-integrated accelerometer can have an angular deviation of up to 10 degrees from the textile surface. Nevertheless, applications in rehabilitation and health care can benefit from textile-integrated accelerometers.