title: Polymer substrate temperature sensor array for brain interfaces.
abstract: We developed an implantable thin film transistor temperature sensor (TFT-TS) to measure temperature changes in the brain. These changes are assumed to be associated with cerebral metabolism and neuronal activity. Two prototype TFT-TSs were designed and tested in-vitro: one with 8 diode-connected single-ended sensors, and the other with 4 pairs of differential-ended sensors in an array configuration. The sensor elements are 25 ~ 100 pm in width and 5 μm in length. The TFT-TSs were fabricated based on high-speed ZnO TFT process technology on flexible polyimide substrates (50 μm thick, 500 μm width, 20 mm length). In order to interface external signal electronics, they were directly bonded to a prototype printed circuit board using anisotropic conductive films The prototypes were characterized between 23 ~ 38 °C using a commercial temperature sensor and custom-designed temperature controlled oven. The maximum sensitivity of 40 mV/°C was obtained from the TFT-TS.
authors.affiliation: Department of Engineering Sciences and Mechanics, The Pennsylvania State University, University Park, PA16802, USA. insoo@ psu.edu
authors.forename: Insoo
authors.initials: I
authors.lastname: Kim
authors.forename: Ho Him R
authors.initials: HH
authors.lastname: Fok
authors.forename: Yuanyuan
authors.initials: Y
authors.lastname: Li
authors.forename: Thomas N
authors.initials: TN
authors.lastname: Jackson
authors.forename: Bruce J
authors.initials: BJ
authors.lastname: Gluckman
mesh_terms: D015374:Biosensing Techniques; D001831:Body Temperature; D001921:Brain / Q000502:physiology*; D002138:Calibration; D006801:Humans