Development of biobattery that uses beef fat: Kyoto University group advancement shows promise for medical applications

A collaborative research group including Assistant Professor Keisei Sowa from the Graduate School of Agriculture in Kyoto University, Murata Manufacturing Co., Ltd., and BioSerenTach has successfully developed a biobattery that uses fat as fuel. They created a prototype patch with layered lipase-containing microneedles, glycerol-oxidizing anodes, and oxygen-reducing cathodes, demonstrating possible power generation of 0.1 milliwatts from beef fat.

Biobatteries are power generation devices that use catalytic reactions through oxidoreductase enzymes. By modifying the negative electrode (anode) with enzymes that oxidize various fuels and the positive electrode (cathode) with enzymes that reduce oxygen, electricity can be extracted from compatible fuels. Since enzymes that function most efficiently at room temperature, atmospheric pressure, and neutral conditions are used as catalysts, these devices have characteristics such as moderate operating conditions and high biocompatibility.

The research group developed a fat-fueled biobattery by combining a biobattery with lipase-containing microneedles. First, when fat-decomposing enzymes are injected into beef through microneedles, glycerol is generated through fat hydrolysis. The generated glycerol is taken up through the microneedles, and power generation is performed using a biobattery that uses the glycerol as fuel.

While this biobattery uses beef fat as fuel, future applications in the medical field targeting humans are anticipated. By changing the enzymes used, not only fat but various other substances can be utilized as fuel, making it possible to develop power sources for devices that work inside the body.

Sowa commented: "Through this collaborative research, we were able to pioneer new applications for biobatteries that differ from conventional ones. By considering fat as fuel, completely new applications in the medical field become possible, and we will explore their feasibility through future research. Moving forward, by utilizing the advanced catalytic functions that nature provides, we will create innovative technologies that enrich humanity and the Earth, and work on the social implementation of our research results."