Montgomery, K. et al. Nat. Methods 12, 969–974 (2015).

Park, S.I. et al. Nat. Biotechnol. doi:10.1038/nbt.3415 (9 November 2015).

Optogenetic manipulation of neural activity has become a workhorse in neurobiology, but standard optical illumination via cables and external light sources can interfere with normal behaviors in freely moving animals. Wirelessly powered devices can overcome this limitation. Montgomery et al. reported an implantable light-emitting diode (LED) device that is controlled and powered with a radio-frequency power source. Park et al. developed a soft, stretchable LED device that works similarly. Although the latter device is probably more compatible with chronic experiments because it causes less tissue damage, the former device is easier to build. Both research groups have used the devices to stimulate pain circuitry in the peripheral nervous system and in the spinal cord of freely behaving mice.