Building Fabric Power Converters for Wearable Energy Harvesting Applications

Fabric is emerging as a viable substrate for wearable circuits with advancements in electronic textile (e-textile) technologies. However, incorporating electronics into textiles faces many unique challenges, mainly stemming from the high resistivity of conductive fibers and inks, as well as the difficulty of establishing reliable connections between the fabric and circuit components. This study proposes a hybrid approach to overcome these challenges by using both copper tape and conductive fabric to create circuits on fabric. The combination of the two materials was measured to be approximately two times more resistive than a conventional flexible copper sheet. Extra resistance was also found to come from the connection of multiple pieces of tape due to the higher-resistance adhesive. Despite being more resistive than desired, the on-fabric boost converter exhibited around 75% efficiency at the rated power of 1-W. The converter’s operation was maintained without interruption when the fabric converter transitioned from a flat state to a bent state and back.