A scalable yarn-based biobattery for biochemical energy harvesting in smart textiles

Fiber-based and fiber-formed power sources that can be seamlessly integrated into fabrics are of great importance to the development of smart textiles. In this regard, possible use of Microbial Fuel Cells (MFCs) and bio-batteries as power supplies has not been fully explored because of issues as large device footprint, low power density, difficulties in device integration and stack operations. Herein, an incorporable, flexible, and easily scalable yarn-based biobattery that generates green electricity from bacterial respiration is presented. This biobattery consists of one anodic and one cathodic yarn that are prepared with solution-processible materials for the ease of fabrication. The power output of this biobattery is easily scalable by controlling the length of the yarns for parallel connections or by connecting multiple yarns in series. The maximum current densities for 3 series, 2 parallel and single biobatteries are 110.65 A m(-3) , 277.10 A m(-3) and 315.45 A m(-3), respectively. The maximum power densities are 22.10 W m(-3), 19.14 W m(-3), and 22.12 W m(-3), respectively. Moreover, these yarn-based biobatteries can potentially be knitted or woven into smart packaging or embroidered into larger smart fabrics, energizing real-world applications such as Internet-of-things (IoT) devices and wearable electronics.