a, A rat with an implanted device during activation of the μLEDs. b, A device that combines a wireless control/power management module, an optical sensing/stimulation module and a wireless power transfer module. c, Optical image of a strain gauge and μLEDs wrapped around the bladder of a rat in an expanded state. d, Result of closed-loop optogenetic neuromodulation. Reproduced from Ref.141 Copyright 2019 Springer Nature.