  Organic Electrochemical Transistors are considered today as a key technology
to interact with biological medium through their intrinsic ionic-electronic
coupling. In this paper, we show how this coupling can be finely tuned (in
operando) post-microfabrication via electropolymerization technique. This
strategy exploits the concept of adaptive sensing where both transconductance
and impedance are tunable and can be modified on-demand to match different
sensing requirements. Material investigation through Raman spectroscopy, atomic
force microscopy and scanning electron microscopy reveals that
electropolymerization can lead to a fine control of PEDOT microdomains
organization, which directly affect the iono-electronic properties of OECTs. We
further highlight how volumetric capacitance and effective mobility of
PEDOT:PSS influence distinctively the transconductance and impedance of OECTs.
This approach shows to improve the transconductance by 150% while reducing
their variability by 60% in comparison with standard spin-coated OECTs.
Finally, we show how to the technique can influence voltage spike rate hardware
classificationwith direct interest in bio-signals sorting applications.
