Flexible PCB Connection Methods for Wearable Energy Harvesting Applications

Abstract

Powering wearables using energy-harvesting technologies is a viable approach to increase their reliability. However, integrating electronics with fabric presents challenges requiring unique design solutions. Forming stable physical connections, from the power source to the device load and the power converter in between, is a crucial aspect of the design. Further, the connections must not interfere with user activity or affect the wearable's functionality. The primary connections investigated in this study are a) attachment of a flexible PCB to fabric and b) construction of on-fabric conductive traces. Several methods for establishing these connections are proposed and tested to identify the most efficient methods. The results indicate machine-sewn conductive thread to have the least resistance and be the most resilient method, whereas buttons performed the second best while enabling detachability. For on-fabric conductive traces, a couching method reinforced with a conductive ribbon showed the best performance regarding resistivity and power loss.