Enhancement of Interface Characteristics of Neural Probe Based on Graphene, ZnO Nanowires, and Conducting Polymer PEDOT

• Published in: ACS applied materials & interfaces Vol. 9; no. 12; pp. 10577 - 10586
• Main Authors: Ryu, Mingyu, Yang, Jae Hoon, Ahn, Yumi, Sim, Minkyung, Lee, Kyung Hwa, Kim, Kyungsoo, Lee, Taeju, Yoo, Seung-Jun, Kim, So Yeun, Moon, Cheil, Je, Minkyu, Choi, Ji-Woong, Lee, Youngu, Jang, Jae Eun
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 29-03-2017
• Subjects: Bridged Bicyclo Compounds, Heterocyclic; Graphite; Nanowires; Polymers; Zinc Oxide; neural probe; brain−machine interface; PEDOT; nanowires; graphene
• ISSN: 1944-8244; 1944-8252
• DOI: 10.1021/acsami.7b02975

In the growing field of brain–machine interface (BMI), the interface between electrodes and neural tissues plays an important role in the recording and stimulation of neural signals. To minimize tissue damage while retaining high sensitivity, a flexible and a smaller electrode with low impedance is required. However, it is a major challenge to reduce electrode size while retaining the conductive characteristics of the electrode. In addition, the mechanical mismatch between stiff electrodes and soft tissues creates damaging reactive tissue responses. Here, we demonstrate a neural probe structure based on graphene, ZnO nanowires, and conducting polymer that provides flexibility and low impedance performance. A hybrid Au and graphene structure was utilized to achieve both flexibility and good conductivity. Using ZnO nanowires to increase the effective surface area drastically decreased the impedance value and enhanced the signal-to-noise ratio (SNR). A poly­[3,4-ethylenedioxythiophene] (PEDOT) coating on the neural probe improved the electrical characteristics of the electrode while providing better biocompatibility. In vivo neural signal recordings showed that our neural probe can detect clearer signals.