Multimodal Electrocorticogram Active Electrode Array Based on Zinc Oxide‐Thin Film Transistors

Abstract

Active electrocorticogram (ECoG) electrodes can amplify weak electrophysiological signals and improve anti‐interference ability; however, traditional active electrodes are opaque and cannot realize photoelectric collaborative observation. In this study, an active and fully transparent ECoG array based on zinc oxide thin‐film transistors (ZnO TFTs) is developed as a local neural signal amplifier for electrophysiological monitoring. The transparency of the proposed ECoG array is up to 85%, which is superior to that of the previously reported active electrode arrays. Various electrical characterizations have demonstrated its ability to record electrophysiological signals with a higher signal‐to‐noise ratio of 19.9 dB compared to the Au grid (13.2 dB). The high transparency of the ZnO‐TFT electrode array allows the concurrent collection of high‐quality electrophysiological signals (32.2 dB) under direct optical stimulation of the optogenetic mice brain. The ECoG array can also work under 7‐Tesla magnetic resonance imaging to record local brain signals without affecting brain tissue imaging. As the most transparent active ECoG array to date, it provides a powerful multimodal tool for brain observation, including recording brain activity under synchronized optical modulation and 7‐Tesla magnetic resonance imaging.

Electrocorticogram (ECoG): Engineering Approaches and Clinical Challenges for Translational Medicine

“…For example, optical imaging and optogenetic stimulation have been integrated into ECoG electrodes for research purposes. [93,94] A drug-delivery function was added for direct and focal injection into the central nervous system. [95] Bioabsorbable materials and minimally invasive electrode array structures have been developed to reduce surgical risks.…”

7T Magnetic Compatible Multimodality Electrophysiological Signal Recording System

“…Channelrhodopsin-2 (ChR2) is a blue light-activated cationic channel commonly used in optogenetics [31]. Using 473-nm blue light to activate cortical neurons transfected with the CHR2 virus in the S1 cortex of mice, a typical light-evoked signal was recorded using a transparent electrode [32] and EP signal acquisition system in Figure 5b-d. As photo stimulation was turned on, a large negative peak was recorded, and the signal slowly returned to baseline after the stimulation ended.…”

Antenna Effect in Large Area Palladium-Coated Electrostatically Formed Silicon Nanowire for Ppb Level Hydrogen Sensing

“…Hydrogen gas (H 2 ) sensors for sub-ppm levels are vital for the early indication of leaks in various facilities of green energy, storage, chemical industry, nuclear reactors, etc. 1,2 For example, ppb level H 2 sensors are beneficial for early safety warnings and the elimination of thermal runaway in lithiumion batteries, 3 and they are also important for human breathaided medical diagnosis, 4 as the amount of H 2 concentration present in human breath is exceedingly low, 5 below 1 ppm. Observing the presence of hydrogen at ppm levels can also function as an indirect measure for CO 2 , a crucial component in indoor ventilation.…”