Dopant-Dependent Electrical and Biological Functionality of PEDOT in Bioelectronics

The aspiration to interact living cells with electronics challenges researchers to develop materials working at the interface of these two distinct environments. A successful interfacing coating should exhibit both biocompatibility and desired functionality of a bio-integrated device. Taking into account biodiversity, the tissue interface should be fine-tuned to the specific requirements of the bioelectronic systems. In this study, we pointed to electrochemical doping of conducting polymers as a strategy enabling the efficient manufacturing of interfacing platforms, in which features could be easily adjusted. Consequently, we fabricated conducting films based on a poly(3,4-ethylenedioxythiophene) (PEDOT) matrix, with properties modulated through doping with selected ions: PSS− (poly(styrene sulfonate)), ClO4− (perchlorate), and PF6− (hexafluorophosphate). Striving to extend the knowledge on the relationships governing the dopant effect on PEDOT films, the samples were characterized in terms of their chemical, morphological, and electrochemical properties. To investigate the impact of the materials on attachment and growth of cells, rat neuroblastoma B35 cells were cultured on their surface and analyzed using scanning electron microscopy and biological assays. Eventually, it was shown that through the choice of a dopant and doping conditions, PEDOT-based materials can be efficiently tuned with diversified physicochemical properties. Therefore, our results proved electrochemical doping of PEDOT as a valuable strategy facilitating the development of promising tissue interfacing materials with characteristics tailored as required.

Charge transport and thermoelectric conversion in solution-processed semicrystalline polymer films under electrochemical doping

Charge transport and thermoelectric conversion mechanisms in doped semicrystalline polymer films are key issues in the field of wearable electronics, whereas the complex film structure consisting of crystalline domains and non-crystalline boundaries prevents sufficient understanding of them. In this study, we fully clarify the roles of the domains and the boundaries in a typical semicrystalline polymer on macroscopic charge transport under continuous electrochemical doping. In the crystalline domains, a multi-step transformation of the transport properties from effectively metallic behavior to weak localization (WL) to variable-range hopping (VRH) is found with decreasing temperature and doping level. On the other hand, at the domain boundaries, the effectively metallic conduction changes directly to VRH. Based on these results, the extremely complicated phase diagram, including the coexistence of the WL and VRH processes, is well explained. The proposed transport mechanism further explains the thermoelectric properties of the film.

Электрохимический контроль электронной проводимости тонких пленок металлоорганических полимеров

The dependence of the conductivity in thin films of polymer complexes of nickel with N4 ligands with macrocyclic and chelate structure on the doping level has been studied by the electrochemical in-situ conductance method. The electrochemical conductivity window of polymers depends on the structure of the monomers and approached 1.2 V for the macrocyclic complex. Electrochemical doping changes the electrical resistance of the investigated materials by 4 orders of magnitude

Polymer light-emitting electrochemical cells with ultralow salt content: performance enhancement through synergetic chemical and electrochemical doping actions

Polymer light-emitting electrochemical cells (PLECs) employing silver trifluoromethanesulfonate (Ag triflate) salt are demonstrated. The red-emitting PLECs contained 0.2–1 wt% salt, but exhibited peak luminance of 6,000 cd/m2, with high efficiency...