Power generation using diabetic urine as fuel in a paper-based microfluidic fuel cell with a ZnO/Ni-based composite anode

This work presents, for the first time, power generation using diabetic urine as fuel. The energy conversion is achieved through a paper-based microfluidic fuel cell. Urine has recently gained attention as a source of novel biomarkers for early disease detection, making the use of diabetic urine as fuel particularly relevant to the development of autonomous portable medical devices. A key challenge in using diabetic urine as fuel lies in the fact that it contains various molecules and compounds that can block or poison the fuel cell's electrodes. This study introduces a selective catalyst of ZnO and nickel-based particles that oxidize the urea in human urine. Different concentrations of Ni (3%, 6%, and 9%) were evaluated to optimize catalyst activity. The best performance of the diabetic urine-microfluidic fuel cell was achieved with the ZnO-Ni at 3%, yielding a maximum voltage of 0.89 V, a maximum current density of 1.18 mA cm−2, and a maximum power density of 1.26 mW cm−2. These results demonstrate the potential for enhancing point-of-care devices through paper-based microfluidic fuel cell stacks.