We use fruit flies as a simple model organism for testing our new sensors. Using OLEDs, we stimulated motor neurons in fruit fly larvae (Morton et al. Sci. Rep. 6, 31117 (2016), Ciccone et al. Adv. Funct. Mater., 2110590 (2021)) as well as primary mouse hippocampal neurons (Morton et al. Adv. Biosyst. 3, 1800290 (2019)). In order to improve spatial resolution for optogenetics, we developed microstructured OLEDs and used those to stimulate sensory neurons in individual segments of Drosophila larvae (Murawski et al. Nat. Comm. (2020)). We also imaged calcium dynamics in the ventral nerve cord of Drosophila larvae with OLED illumination (Murawski et al. Adv. Mater. 31, 1903599 (2019)) and developed a smartphone app that allows controlling Drosophila behaviour using smartphone displays (Meloni et al. Sci. Rep. 10, 17614 (2020)).