IEEE Transactions on Biomedical Engineering

Featured Articles
Compact Optical Neural Probes with up to 20 Integrated Thin-Film μLEDs Applied in Acute Optogenetic Studies
Slender silicon-based optical probes comprising up to 20 thin-film micro light-emitting diodes (µLEDs) are realized as compact devices for optogenetic research. The μLEDs are structured on GaN-on-sapphire and transferred onto silicon using a wafer-level bonding and laser lift-off process. This technology allows processing the GaN layer stack from both sides, thereby maximizing the µLED efficiency to an emittance of 56 mWmm−2 at 5 mA. The thermal characterization of the optical probes reveals a temperature increase of up to 1.5 K. Acceptable neuronal responses are elicited at radiant flux values between 1.36 μW and 17.5 μW, successfully demonstrating layer-specific cortex stimulation... Read more