A Flexible Origami Opto-Electro Array For In Vivo Optogenetic Neurostimulation and Neurophysiology Recording

This paper reports a thin-film, three-dimensional (3D) opto-electro array with four individually addressable microscale light-emitting diodes (μ-LEDs) capable of surface illumination of the cortex and nine penetrating electrodes for simultaneous recording of light-evoked neural activities. Inspired by the origami concept, a carefully designed "bridge + trench" structure facilitates the conversion of the array from two-dimensional (2D) to 3D while avoiding mechanical damage to thin film metal. Before device transformation, the shape and dimensions of the 2D array can be customized, making it versatile for a variety of applications. The array is packaged using polyimide (PI) and polydimethylsiloxane (PDMS) to ensure the device’s mechanical flexibility and biocompatibility. The efficacy of the device is characterized both in vitro and in vivo.