Rongyu Tang

Fabrication of strongly adherent platinum black coatings on microelectrodes array

Platinum black coating can effectively improve the performance of MEAs (microelectrodes array) in neural signal transduction, though its lack of adhesion strength and durability tampers its usage in long term experiments. Here a new method of composite electrodeposition provides highly adhesive platinum black coating that enables MEAs for a month’s long task and repeatable utilization. The new method was compared with present techniques on multiple aspects, e.g. actual surface area, surface morphology, interfacial impedance, durability and real application tests. Results show that the new composite coating provides greatly improved durability without compromising its performances. Neural cells were cultured on these MEAs for 40 days in vitro and spontaneous action potentials with high signal/noise ratio were recorded. Theoretical model and simulation provided preliminary understanding on the mechanism of this strengthened platinum black coating.

32-site microelectrode modified with Pt black for neural recording fabricated with thin-film silicon membrane

Multi-electrode array is an important tool in the study of neural-network, cognition, remembrance, as well as brain-computer-interface, etc. Fork-like 32-site microelectrodes are developed with silicon. By use of integrated circuit technology, the length of the electrodes, the area of the recording sites, as well as the spaces between the sites are closely controlled. SiO2/SiNx/SiO2 composite dielectric membrane and Pt black are introduced to improve the characteristics of the electrodes. The whole thickness of the thin-film probe was 21 μm. By combining the modifying process with the micro-fabrication method, this kind of silicon based microelectrode satisfies high-density recording and the performance characterization is evaluated by test in vitro and in vivo.