Wireless In Vivo Biofuel Cell Monitoring

Enzymatic reactions involving glucose hold the potential for building implantable biosensors and embedded power generators for various medical applications. While Biofuel cells (BFCs) such as enzymatic glucose/O ₂ are ensured to benefit from abundant chemical resources that can be harvested in the immediate environment of the human body, the highly critical in vivo kinetics of biofuel cell is not yet fully understood. Unfortunately, existing solutions for real-time monitoring of the reaction on rodents are not possible today, or too bulky, which has a biasing impact on the animal behavior. This work presents a light, battery-less, and wireless strategy to continuously monitor a BFC implanted in a laboratory rat using a Frequency Identification (RFID) link. An extremely lightweight and flexible tag antenna of footprint lower than 10 cm ² is presented with communication capability above 60 cm in field environment. The operational capabilities are demonstrated with a 24-hour continuous monitoring of an enzymatic glucose/O ₂ reaction, both in vitro and in vivo.