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

This article focuses on the development and evaluation of a paper-based microfluidic fuel cell (μFC) that generates power using diabetic human urine as fuel. The study introduces a ZnO/nickel (Ni)-based composite anode catalyst, where Ni exists as nickel hydrazine and ammonia complexes, to selectively oxidize urea in urine despite the presence of potentially electrode-poisoning biomolecules found in diabetic urine. Testing with normal and diabetic urine samples demonstrated that the ZnO–Ni composite with 3% Ni concentration achieved the best performance, yielding a maximum voltage of 0.89–0.95 V, current densities of 1.18–2.12 mA/cm², and power densities of 0.13–0.24 mW/cm², outperforming ZnO alone and comparable or superior to previously reported urine-fueled microfluidic fuel cells. These findings suggest the potential of such fuel cells to serve as autonomous power sources in portable point-of-care (POC) and lab-on-a-chip (LOC) medical diagnostic devices, even when using complex biological fluids like diabetic urine.