High-performance transistors for bioelectronics through tuning of channel thickness

Jonathan Rivnay (1) , Pierre Leleux (2, 1) , Marc Ferro (2, 1) , Michele Sessolo (1, 2) , Adam Williamson (3) , Dimitrios Koutsouras (1) , Dion Khodagholy (1) , Marc Ramuz (1) , Xenofon Strakosas (1) , Roisin Owens (1) , Christian Benar (3) , Jean-Michel Badier (3) , Christophe Bernard (3) , George Malliaras (1)

1 BEL-ENSMSE - Département Bioélectronique
2 Ecole Natl Super Mines Gardanne
3 INS - Institut de Neurosciences des Systèmes

Despite recent interest in organic electrochemical transistors (OECTs), sparked by their straightforward fabrication and high performance, the fundamental mechanism behind their operation remains largely unexplored. OECTs use an electrolyte in direct contact with a polymer channel as part of their device structure. Hence, they offer facile integration with biological milieux and are currently used as amplifying transducers for bioelectronics. Ion exchange between electrolyte and channel is believed to take place in OECTs, although the extent of this process and its impact on device characteristics are still unknown. We show that the uptake of ions from an electrolyte into a film of poly(3,4-ethylenedioxythiophene) doped with polystyrene sulfonate (PEDOT:PSS) leads to a purely volumetric capacitance of 39 F/cm 3 . This results in a dependence of the transconductance on channel thickness, a new degree of freedom that we exploit to demonstrate high-quality recordings of human brain rhythms. Our results bring to the forefront a transistor class in which performance can be tuned independently of device footprint and provide guidelines for the design of materials that will lead to state-of-the-art transistor performance.

Domains: Life Sciences [q-bio]

Jonathan Rivnay, Pierre Leleux, Marc Ferro, Michele Sessolo, Adam Williamson, et al.. High-performance transistors for bioelectronics through tuning of channel thickness. Science Advances , 2015, 1 (4), pp.e1400251. ⟨10.1126/sciadv.1400251⟩. ⟨hal-03349330⟩