The ability to target and stimulate neurons brings a host of benefits including better understanding brain function and treating neurological diseases. Currently, state-of-the-art microelectrode arrays (MEAs) can stimulate neurons with high precision, but they lack cell-type specificity and require invasive implantation that can result in tissue damage—think stimulators used to help patients with tremors. Professor of Materials Science and Engineering, and Biomedical Engineering, Tzahi Cohen-Karni and his team have been exploring new materials to allow remote photostimulation, or the use of light to stimulate cells.