HectoSTAR μLED Optoelectrodes for Large‐Scale, High‐Precision In Vivo Opto‐Electrophysiology (Adv. Sci. 18/2022)

Multifunctional Fiber‐Based Optoacoustic Emitter as a Bidirectional Brain Interface

“…We introduced the optoacoustic stimulation as a new strategy for “writing” in the bidirectional neural interface. Compared with previous optoelectrode devices based on optogenetics [ 26,27,29 ] and photothermal, [ 72,73 ] the optoacoustic stimulation enabled by mFOE reduces the barrier of transgenic techniques for applications in primates and potentially human, and avoids the thermal toxicity. At the same time, it offers the spatial precision benefit from the confined ultrasound field.…”

“…For example, monolithically integrated micro‐light‐emitting‐diodes (µLEDs) were used to reduce the complexity of light‐guide structures and significantly boosted the number of stimulation sites and stimulation resolution. [ 25,26 ] Alternatively, a high‐throughput thermal drawing method has been used to integrate the function components, for example, electrodes, microfluidic channels, and optical waveguides, to the flexible multifunctional polymer fiber. [ 27,28 ] Through this approach, the flexible fiber probes showed low bending‐stiffness and enabled multifunctionalities, including optical waveguide, electrical recording and drug delivery.…”

Development of wafer-scale multifunctional nanophotonic neural probes for brain activity mapping

“…In contrast, Si-based neural probes integrated with optoelectronic materials can realize more than a hundred microscale light emitting diodes (either μ-LEDs [28][29][30][31] or μ-OLEDs 32 ) and microelectrodes on probe shanks. For example, ref.…”

“…For example, ref. 31 reported the integration of 256 electrodes and 128 μ-LEDs on a probe. However, each emitter is limited to a Lambertian emission profile, constraining its versatility for neuroscience applications requiring patterned illumination, such as light-sheet imaging.…”

“…In addition, the low wall-plug efficiency of the μ-LEDs and μ-OLEDs can limit the optical output power to tens of μW or less to minimize heating in brain tissue or to avoid interconnect failure due to the drive current. 28,29,31,33 This limitation means that the devices may be less suitable for applications that require high power to illuminate large brain volumes over long durations. 34,35 An alternative class of light delivery implants use microand nano-scale waveguides patterned on Si wafers.…”