Biocompatible implantable biofuel cell

The present work demonstrates the in vivo biocompatibility and operation of a biofuel cell enclosed by a chitosan membrane. The measured power output in the range of 6.2 to 20.7 μW cm^-2 (applied current from 10 to 70 μA) indicated that glucose and oxygen can reach the enzymes in the 3D matrix without any need for a buffer solution in the implant or a hydration step. This is very important to simplify the preparation and sterilization steps, to avoid contamination and to favour the close communication between the device and body fluids. This optimized biofuel cell is now being applied to supplying power for a leadless pacemaker.