  One of the major limitation of standard top-down technologies used in today's
neuromorphic engineering is their inability to map the 3D nature of biological
brains. Here, we show how bipolar electropolymerization can be used to engineer
3D networks of PEDOT:PSS dendritic fibers. By controlling the growth conditions
of the electropolymerized material, we investigate how dendritic fibers can
reproduce structural plasticity by creating structures of controllable shape.
We demonstrate gradual topologies evolution in a multi-electrode configuration.
We conduct a detail electrical characterization of the PEDOT:PSS dendrites
through DC and impedance spectroscopy measurements and we show how organic
electrochemical transistors (OECT) can be realized with these structures. These
measurements reveal that quasi-static and transient response of OECTs can be
adjust by controlling dendrites' morphologies. The unique properties of organic
dendrites are used to demonstrate short-term, long-term and structural
plasticity, which are essential features required for future neuromorphic
hardware development.
