학술논문
A 12.5mg mm-Scale Inductively-Powered Light-Directivity-Enhanced Highly-Linear Bidirectional Optogenetic Neuro-Stimulator
Document Type
Conference
Author
Source
2020 IEEE Custom Integrated Circuits Conference (CICC) Custom Integrated Circuits Conference (CICC), 2020 IEEE. :1-4 Mar, 2020
Subject
Language
ISSN
2152-3630
Abstract
The design, development, and experimental validation of a mm-scale self-contained bidirectional optogenetic stimulator are presented. A novel current-mode LED driving circuit architecture is employed that allows for fully-linear control of optical stimulation up to I LED ?10mA, with the smallest reported 200mV headroom, significantly boosting the electrical-to-optical energy conversion efficiency. The system's energy efficiency is further improved by inkjet printing of custom-designed optical µlenses on top of the device to enhance the generated light directivity. Our results show a 30.46× irradiance (optical power per area) improvement for the same electrical power consumption. In addition to the two stimulation channels, the SoC integrates two recording channels for LFP recording and digitization, and is powered through an on-chip coil with PTE?2.24%. Full experimental SoC electrical and optical characterization and in vitro measurement results are reported.