Microwave to near-infrared conversion with a millimeter-scale wireless laser for activating molecular transducers.

Light-activated molecular transducers enable precise manipulation of biological processes and are thus powerful tools for studying or treating disease. Their use in vivo, however, is currently limited by the low penetration of light through biological tissue. While electromagnetic fields at microwave frequencies can penetrate thick tissue, they do not provide direct control over molecular transducers. Here, we describe a miniaturized, wirelessly powered laser capable of delivering high intensity near-infrared light in tissue. The device is about 2.5 mm in the largest dimension, weighs less than 30 mg, and can be wirelessly powered through >1 cm of tissue. This device could be used in emerging bioelectronics-based treatments that combine the precision of light with the penetration depth of microwaves.