Fabrication of carbon fibre microelectrode array for neural recording

Abstract

Microelectrodes are unique electrodes used to study the electrical activity of individual biological cells. Currently microelectrodes are conventionally made with glass or metal. However, these materials are harmful to living organisms. Carbon fibres are more harmless to living organisms due to its chemical and physical properties. This objective of this project is to develop and evaluate multichannel carbon fibre microelectrode array (MEA) for long-time in-vivo neural recording. Firstly, carbon fibres are assessed on their suitability as a microelectrode. The electrical impedance, Z, of the carbon fibre microelectrode must be less than 2MΩ when subjected to an electrical current of 1khz. Afterwards, several methods of insulating the carbon fibres were conducted and evaluated: isolation through 3d printed housing, insulation with polyimide tubing, insulation with nail polish, anodic electrophoretic deposition. In the final design of the microelectrode array, anodic electrophoretic deposition is chosen. The assembly of the microelectrode involves the incorporation of 3d printed parts and the processed carbon fibres. The microelectrode array is implanted in the brain of the Madagascar Hissing Cockroach and evaluated to be satisfactory in its recording capability. Documented with the use of intan RHX recording equipment. Improvements via experimental verification such as SEM imaging are suggested to improve the signal-to-noise ratio and quality of signal recording of the microelectrode array.