Kim, T.-i. et al. Science 340, 211–216 (2013).

Optogenetic experiments in neuroscience often involve penetrating the brain with devices that can deliver and detect light and record the electrical activity of neurons, ideally with 'all-in-one' functionality. It is also desirable that these devices be small and as nondisruptive to the animal's physiology and behavior as possible. Kim et al. describe a flexible, wireless, ultrathin optoelectronic system that offers several functionalities. The device incorporates several inorganic microemitting diodes for spatially confined, cellular-scale delivery of photons, a microscale inorganic photodetector and a temperature sensor. It also contains microelectrodes that measure extracellular voltage signals in the direct vicinity of the sensor and that can be used for electrical stimulation. The researchers demonstrate how these devices can be used for optogenetic experiments in behaving mice.