Self-doped conducting polymers in biomedical engineering: Synthesis, characterization, current applications and perspectives

Recent studies willingly agree that conducting polymers (CPs) are attractive materials for biomedical engineering purposes, mainly because of their unique physicochemical characteristics combining electrical conductivity and high biocompatibility. Nevertheless, the applicability of CPs is restricted by their limited stability under physiological conditions, associated with a decrease in electrical conductivity upon dedoping. Accordingly, modifying chemical structure of CPs to exhibit a self-doping effect seems to be an appealing approach aimed to enhance their functionality. The aim of this review is to provide a current state-of-the-art in the research concerning self-doped CPs, particularly those with potential biomedical applications. After presenting a library of available structure modifications, we describe their physicochemical characteristics, focusing on achievable conductivities, electrochemical, optical and mechanical behaviour, as well as biological properties. To highlight high applicability of self-doped CPs in biomedical engineering, we elaborate on biomedical areas benefiting most from using this type of conducting materials.

Seebeck coefficients of regioregular poly(3-hexylthiophene) correlated with doping levels

Thermoelectric properties of regioregular poly(3-hexylthiophene) (P3HT) were investigated in correlation with doping level measured by a potential-step chronocoulometry (PSC) method. It was found that the log-log plot of Seebeck coefficients against doping levels showed a good linearity, whose slope value was around -1.

Conducting redox polymers with non-activated charge transport properties

The conduction mechanism of terephthalate-substituted polythiophene is dominated by residual scattering and shows a negative dependence on temperature.