Nanosecond-Response and Low-Thermal-Diffusion Micro-LED Arrays for High-Speed Optogenetic Modulation With Artifact...

A fundamental challenge within the field of optogenetics is the attainment of simultaneous high spatial resolution, multi-site addressability, and precise temporal control. Conventional optical instruments, such as optical fibers, present restricted scalability and suboptimal spatial control. This study introduces an innovative optogenetic apparatus that surmounts these limitations through the integration of thousands of blue micro-light-emitting diodes by means of a novel ion-implantation pixelation strategy, enabling selective activation via a flexible driver. Operating at a low voltage of 2.9 V, it efficiently stimulates cells with minimal light attenuation within the tissue and low heat production during extended use. Significantly, the device showcases a nanosecond-scale rise time of 49.2 ns, substantially enhancing temporal resolution for high-speed neural modulation. By utilizing a WO₃ metal-semiconductor-metal device as a surrogate optoelectronic platform to emulate cellular response, we demonstrate high-fidelity response recording and notably improved post-stimulation activity. Moreover, we characterize artifacts stemming from various light pulses and achieve substantially reduced-artifact stimulation using 100 ms short pulses.