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 Tuesday, February 1, 2011 Allen 101X Auditorium 4:00 – 5:00 Flexible 4,096-­‐Pixel Multi-­‐Electrode Arrays of Electrodes, CMOS and Image Sensors: a tool for interfacing retinal circuitry and a basis for retinal prosthesis Abstract Long-­‐Sheng Fan National Tsing Hua University/Univ. California, Berkeley To achieve localized retinal neural stimulation with high granularity over reasonable field of view within power constraints, we integrated a flexible 4,096-­‐element retina chip 30 µm in thickness using a flexible 180nm CMOS Image Sensor (CIS) technology. The retina chip is 3x3 mm in size (including multiplexing electronics for pixel characterizations) with an array of 10 µm electrodes and photo sensors 30 µm in pitch. The flexible format allows better proximity between electrodes and retina neurons for localized stimulation, and the integrated local electronics allows supplying individual electrode the adequate and appropriate stimulation waveforms right next to each individual electrodes. The chip senses local light intensity and generates corresponding biphasic current at each pixel. Images are projected onto the chip and corresponding biphasic currents for stimulating retina tissue from each pixel are mapped. Loose patch and whole-­‐cell patch clamp techniques in vitro are used to characterize the mouse retinal ganglion cells responses on these arrays with bipolar cells facing down. With local active devices and signal processing capability, it could also potentially be an enabling tool to interface retinal neurons to the individual cell level for studying retinal neural network. Biography Long-­‐Sheng Fan received his MS & Ph.D. degrees in Electrical Engineering and Computer Sciences both from the University of California at Berkeley. He joined IBM Almaden Research Center as a Research Staff Member working on magnetic sensors, AFM recording and he was an original advocator for dual-­‐
stage servo in magnetic drives and demonstrated a magnetic recording servo track density beyond 50kTPI using a multilevel metal MEMS microactuator technology, which was transferred to an IBM pilot line. He has served as a section editor for Sensors and Actuators (1994-­‐1997), a government consultant and a member of proposal review panel of NSF and NIH, and he is the IEEE Technical Program Vice Chair of Transducers 2009 and designated Technical Program Chair of IEEE Transducers 2011. Dr. Fan joined National Tsing-­‐Hua University as a Tsing-­‐Hua Professor and the Director of the Institute of Nano Engineering and MicroSystems during 2003-­‐9, and he was the coordinator of Heterogeneous Integration Program of the SoC National Program in Taiwan, promoting MEMS IP reuse with standard process modules & EDA for MEMS/IC co-­‐design. He is an IEEE Fellow and currently a Visiting Professor in EECS, UCB. His academic research interest is in the biomedical microsystems for medical implants & MEMS-­‐enabled medical instruments.