Abstract Understanding complex neuronal circuitry and its functions of a living organism requires a specialized tool which is capable of (i) recording a large ensemble of neuronal signals at single cell resolution, (ii) modulating neuronal activities optogenetically at the same time, and (iii) sustaining functionality for long-term chronic experiments without significant tissue degeneration or device migration. We hereby present an ultra-flexible, minimally-invasive, Michigan-type neural probe for chronic opto-electrophysiology studies: flexLiTE (flexible micro-LED integrated optoelectrodes). flexLiTE incorporates monolithically integrated, soma-sized micro-inorganic LEDs (μILEDs, 12 individually operated) and 32 recording electrodes. The stimulation and recording modalities are integrated by stacking two modules on a flexible shank, resulting in a 115 μm-wide,12 μm-thick, 10 mm-long optoelectrode. From prototype devices, we demonstrated the reliable operation of flexLiTEs for recording and modulation of hippocampal neurons in a freely moving mouse for over ~2 month.

flexLiTE: flexible micro-LED integrated optoelectrodes for minimally-invasive chronic deep-brain study