TY - JOUR AU - Freeman, Daniel K. AU - O'Brien, Jonathan M. AU - Kumar, Parshant AU - Daniels, Brian AU - Irion, Reed A. AU - Shraytah, Louis AU - Ingersoll, Brett K. AU - Magyar, Andrew P. AU - Czarnecki, Andrew AU - Wheeler, Jesse AU - Coppeta, Jonathan R. AU - Abban, Michael P. AU - Gatzke, Ronald AU - Fried, Shelley I. AU - Lee, Seung Woo AU - Duwel, Amy E. AU - Bernstein, Jonathan J. AU - Widge, Alik S. AU - Hernandez-Reynoso, Ana AU - Kanneganti, Aswini AU - Romero-Ortega, Mario I. AU - Cogan, Stuart F. PY - 2017 M3 - Original Research TI - A Sub-millimeter, Inductively Powered Neural Stimulator JO - Frontiers in Neuroscience UR - https://www.frontiersin.org/articles/10.3389/fnins.2017.00659 VL - 11 SN - 1662-453X N2 - Wireless neural stimulators are being developed to address problems associated with traditional lead-based implants. However, designing wireless stimulators on the sub-millimeter scale (<1 mm3) is challenging. As device size shrinks, it becomes difficult to deliver sufficient wireless power to operate the device. Here, we present a sub-millimeter, inductively powered neural stimulator consisting only of a coil to receive power, a capacitor to tune the resonant frequency of the receiver, and a diode to rectify the radio-frequency signal to produce neural excitation. By replacing any complex receiver circuitry with a simple rectifier, we have reduced the required voltage levels that are needed to operate the device from 0.5 to 1 V (e.g., for CMOS) to ~0.25–0.5 V. This reduced voltage allows the use of smaller receive antennas for power, resulting in a device volume of 0.3–0.5 mm3. The device was encapsulated in epoxy, and successfully passed accelerated lifetime tests in 80°C saline for 2 weeks. We demonstrate a basic proof-of-concept using stimulation with tens of microamps of current delivered to the sciatic nerve in rat to produce a motor response. ER -