Stretchable Non‐Enzymatic Fuel Cell‐Based Sensor Patch Integrated with Thread‐Embedded Microfluidics for Self‐Powered Wearable Glucose Monitoring

Wearable sensor patches for continuous or intermittent monitoring of biomolecules from body fluids are highly desired as a stretchable integrated platform conformable and attachable to the human body. However, realizing such integrated sensor patches is very challenging because of the difficulty of achieving full stretchability, controlling transport of the body fluid, and minimizing power consumption. In this study, a stretchable and self-powered microfluidic-integrated sensor patch comprising a stretchable non-enzymatic fuel cell-based sweat glucose sensor and a stretchable cotton thread-embedded microfluidic device is demonstrated. To endow the fuel cell-based glucose sensor with stretchability, the anode and cathode electrodes with catalytic nanoporous Au (NPG) and NPG coated with Pt nanoparticles (PtNPs@NPG), respectively, are formed on an omnidirectionally stretchable substrate with a three-dimensional micropattern that can effectively absorb the stress generated during deformation. In addition, a stretchable microfluidic device made by embedding cotton thread into a polydimethylsiloxane (PDMS) channel for powerless constant absorption and sweat flow is integrated into the fuel cell structure. The fully stretchable microfluidic-integrated self-powered sensor patch demonstrates excellent continuous monitoring of the sweat glucose concentration.