Simultaneous stimulation and recording of cell activity with reference-less sensors: Is it feasible?

The study of neuronal and neurodegenerative diseases requires the development of new tools and technologies to create functional neuroelectronics allowing both stimulation and recording of cellular electrical activity. We present a model that describes electrolyte-gated organic field-effect transistors (EGOFETs) as neural interfaces. We show that our model can be successfully applied to understand the behaviour of a more general class of devices, including both organic and inorganic transistors. We introduce the reference-less (RL-) EGOFET and we show that it might be successfully used as a low cost and flexible neural interface for extracellular recording in vivo without the need of a reference electrode, making the implant less invasive and easier to use. The working principle underlying RL-EGOFETs involves self-polarization and back-gate stimulation, which we show experimentally to be feasible. Our results open the door to using and optimizing EGOFETs and RL-EGOFETs for neural interfaces.