Adhesionable flexible GaN-based microLED array film to brain surface for in vivo optogenetic stimulation

A development of a biocompatible, optical stimulation device capable of adhering to the brain surface and activating spatially separated brain regions is necessary for in vivo optogenetic applications. In this study, a hollow structure for isolating the microLED epitaxial layer was fabricated using the anisotropic KOH wet-etching method. Using a thermal release sheet, a method to transfer microLEDs onto a biocompatible parylene film was established without rotation or misalignment of the microLEDs while retaining their characteristics. Accordingly, a flexible microLED array film was fabricated, which adhered to the surface of the brain of a mouse and exhibited blue emission.

Automated summary

In this study, a biocompatible optical stimulation device was developed that can adhere to the brain surface and activate spatially separated brain regions. By using a hollow structure and a thermal release sheet, microLEDs were successfully transferred onto a biocompatible parylene film without any rotation or misalignment while retaining their characteristics.