GLASSY CARBON ELECTRODES FOR NEURAL INTERFACES

Work package:
Scientific context Neural recording and stimulation require electrodes with suitable electrical and electrochemical properties and good stability in physiological environments [1,2]. Glassy carbon is a promising material because of its chemical stability and broad electrochemical potential window [3,4]. It can be obtained by pyrolysis of organic precursors, allowing its shape and properties to be tailored through processing. However, the relationships between precursor chemistry, carbonisation conditions, carbon structure and electrode performance remain to be established for the materials and processes considered here. Objective The internship will investigate how five organic precursors and pyrolysis conditions affect the structure and electrochemical response of glassy carbon electrodes. The aim is to identify processing conditions that provide reproducible carbon materials with low impedance, useful charge storage capacity and stable behaviour in saline solution. The study will support the subsequent development of carbon microelectrodes for neural interfaces within the CarboNeuro research programme. Experimental programme The student will prepare a limited set of electrodes from selected organic precursors, such as SU-8 resin and a furfuryl alcohol based precursor. Controlled thermal treatments will be used to investigate the effects of carbonisation temperature on shrinkage, morphology and carbon structure. Raman spectroscopy, complemented where appropriate by X-ray diffraction and microscopy, will be used to characterise the resulting materials. Electrochemical measurements will include cyclic voltammetry and electrochemical impedance spectroscopy in saline solution. The student will compare the electrodes using a consistent exposed area and measurement protocol, and assess reproducibility and stability under repeated cycling. Depending on progress, a selected surface treatment may be explored to improve the electrochemical response. The work will focus on material development and laboratory measurements; biological validation lies beyond the core internship objectives. Expected outcomes The expected outcome is a comparative assessment linking fabrication conditions and carbon structure to electrochemical performance, together with a reproducible preparation and measurement protocol. The student will gain experience in carbon processing, spectroscopy and electrochemistry, and develop skills in experimental design, quantitative data analysis and scientific communication.