Highly reproduceable tapered fiber optoacoustic emitters by in-situ photothermal curing of PDMS for single neuron stimulation

Precise neural modulation is an important tool in neuroscience research for intervene of specific neural pathways. Photoacoustic is an emerging technology enabling high precision non-genetic neural stimulation in vitro and in vivo. In this paper, we report a new method to prepare a Candle Soot - Tapered Fiber based Optoacoustic Emitter (CSTFOE) through an in-situ photothermal curing process. The emitter created was found with high spatial resolution and efficiency for neuromodulation. In the meanwhile, the in-situ photothermal curing procedure is highly reproducible and allows for fabricating the photoacoustic coating on the tiny tip of the tapered fiber with a diameter less than 20 μm. With the high efficiency and reproducibility, we designed an integrated photoacoustic neuromodulation system incorporating the CSTFOE, a nanosecond pulsed laser for photoacoustic generation, and a function generator for synchronization, achieving effective neuromodulation in vitro.