[Abstract]

My talk will deal with conducting polymer films and devices for flexible, stretchable and healable electronics as well as for implantable electrodes.

The fabrication of stretchable electronic devices is presently rather challenging due to both the limited number of materials showing the desired combination of mechanical and electrical properties and the lack of techniques to process and pattern them.  We reported on transfer patterning process to fabricate high-resolution metal microelectrodes on polydimethylsiloxane (PDMS) by using ultrathin Parylene films (2 μm thick). By combining transfer patterning of metal electrodes with orthogonal patterning of PEDOT:PSS on a pre-stretched PDMS substrate and a biocompatible “cut and paste” hydrogel, we demonstrated fully stretchable organic electrochemical transistors, relevant for wearable electronics, biosensors and surface electrodes to monitor body conditions.

Self-healing electronic materials are highly relevant for application in biology and sustainable electronics. We observed mechanical and electrical healability of PEDOT:PSS thin films. Upon reaching a certain thickness (about 1 µm), PEDOT:PSS thin films damaged with a sharp blade can be healed by simply wetting the damaged area with water. The process is rapid, with a response time on the order of 150 ms. Significantly, after being wetted, the films are transformed into autonomic self-healing materials without the need of external stimulation.

We have recently electropolymerized PEDOT coatings on sharp recording and stimulating electrodes and demonstrated their mechanical and electrochemical stability, via ultrasonication, phosphate buffer solution soaking test, autoclave sterilization and electrical pulsing. In vivo test show promising results for deep brain stimulation and electromyography recording.