Wearable textile biofuel cells for powering electronics

The fabrication and performance of a wearable biofuel cell printed directly onto textile substrates are reported. The textile biofuel cell utilizes physiologically produced sweat lactate as the fuel to generate electrical energy, producing up to 100 mu W cm(-2) at 0.34 V during in vitro experimentation, even after repeated bending stress. Furthermore, the wearable and flexible biofuel cell can be easily integrated with a portable energy storage device for on-demand powering of wearable electronics. To validate energy harvesting, the biofuel cell is integrated into a headband and a wristband, and with the help of an on-board DC/DC converter, extracts energy from perspiring human subjects for direct powering of an LED or a digital watch. Convenient incorporation and removal from a variety of garments are achieved by printing the biofuel cell on a detachable care label. Such textile-based non-invasive biofuel cells can be expected to serve in the future as the power unit for wearable electronics and biomedical devices.