PEDOT:PSS ink-jet printed microelectrodes on paper: towards low-cost and green MEA devices

Microelectrode arrays (MEAs) represent one of the most important technologies for the study of electrogenic cells such as neurons and cardiomyocytes. The current standard commercial devices are expensive tools that researchers reuse extensively, with the downside of degrading the quality of recordings over time. Therefore, a low-cost fabrication process is needed to produce disposable and, possibly, biodegradable MEAs. Here we present a preliminary feasibility study of the fabrication of Poly(3, 4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) microelectrodes on extremely low-cost, parchment paper, through ink-jet printing. To this aim, alkyd resin (AR) was used to improve the superficial proprieties of pristine cellulose paper. The rheological behaviour of ink formulations and the optimal printing parameters have been investigated, and preliminary tests showed resistivity values below those of current commercial gold MEA, in agreement with previous studies on PEDOT:PSS printed electrodes. Our results suggest that AR-treated cellulose paper could be employed to produce low-cost, flexible, and low-environmental impact devices, thus representing an interesting alternative in the field of cellular electrophysiology.