Silicon optrode array with monolithically integrated SU-8 waveguide and single LED light source
- 주제(키워드) in-vivo , LED , MEMS , optogenetics , silicon optrode , SU-8 waveguide
- 등재 SCIE, SCOPUS
- 발행기관 Institute of Physics
- 발행년도 2022
- 총서유형 Journal
- URI http://www.dcollection.net/handler/ewha/000000193344
- 본문언어 영어
- Published As https://doi.org/10.1088/1741-2552/ac7f5f
- PubMed https://pubmed.ncbi.nlm.nih.gov/35797969
초록/요약
Objective. This paper presents a conventional light emitting diode (LED) and polymer waveguide coupled silicon optrode array. Approach. Unique lens design at the waveguide inlet enables a high light coupling efficiency with a single LED light source, and provides small power consumption compatible with a wireless optogenetic neuromodulation system. To increase the light intensity at the waveguide tip, a lensed waveguide is fabricated with epoxy-based photoresist SU-8, which has a plano-convex lens shape at the waveguide inlet to focus the light in the horizontal direction. In addition, a cylindrical lens is assembled in front of the waveguide inlet to focus the source light in the vertical direction. Main results. The glass cylindrical lens and SU-8 plano-convex lens increased the light coupling efficiency by 6.7 dB and 6.6 dB, respectively. The fabricated 1 × 4 array of optrodes is assembled with a single LED with 465 nm wavelength, which produces a light intensity of approximately 2.7 mW mm-2 at the SU-8 waveguide outlet when 50 mA input current is applied to the LED. Each optrode has four recording electrodes at the SU-8 waveguide outlet. The average impedance of the iridium oxide (IrO x ) electroplated recording electrodes is 43.6 kω. Significance. In-vivo experiment at the hippocampus region CA1 and CA2 demonstrated the capability of optical stimulation and neural signal recording through the LED and SU-8 waveguide coupled silicon optrode array. © 2022 IOP Publishing Ltd.
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