Multiplexed Optogenetics with Striped Organic LEDs

Abstract Optogenetic stimulation of living systems enables control of neuronal functions with extraordinary cell‐type specificity. The expression of more than one optogenetic actuator grants the possibility to mediate cellular activity via activation and inhibition upon illumination, with a spatial resolution that is hardly matched by electrical and pharmacological paradigms. In addition, delivering light with adequate spatial resolution is of utmost importance to achieve precise control over targeted cells. To this aim, the design strategy and realization of micro‐structured dual‐color organic light‐emitting diodes (OLEDs) are presented with a high degree of light confinement, reaching optical power densities up to 1 mW mm⁻², microsecond response speed, and device heat‐up below 3 °C upon constant drive conditions at high brightness. The devices are applied for localized stimulation of Drosophila melanogaster (D. melanogaster) larvae expressing BiPOLES as a bidirectional light‐sensitive actuator. The results suggest the presence of an anterior‐posterior hierarchy for motoneuron signal procession, which is concluded from behavioral observations upon simultaneous and timely controlled activation and inhibition of neuronal activity in different larval segments. Thus, the devices are highly effective in generating complex light patterns for multi‐color optogenetics and lay the basis for cell‐specific multiplexed optogenetics in freely moving animals.