The LEDs are overlaid onto a grid of electrodes that is placed on the surface of the brain. Each LED in the device mirrors the activity of a few thousand neurons. In a series of proof-of-concept experiments in rodents and large non-primate mammals, researchers showed that the device can effectively track and display neural activity in the brain corresponding to different areas of the body.

Dayeh and his team used their expertise in working with Gallium Nitride to develop a manufacturing technique for high-efficiency LEDs that do not heat up when they light up and do not damage brain tissues. The material itself is grown on a flat and rigid substrate called Qromis substrate technology. Dayeh’s team at UC San Diego was able to embed thousands of LEDs in flexible films and release them from the substrate in the form of a flexible display panel. Researchers then used inkjet printing to deposit quantum dot inks on the surface of the LEDs to convert their blue light to multiple other colors.