The synthesis of water-processable self-doped polymers has been achieved by direct (hetero)arylation polymerization (DHAP) using water as a cosolvent. The introduction of a counterion covalently attached to the backbone of the polymers enhanced their solubility and the stability of the solutions. Those polymers have shown air-stable electrical conductivities up to 50 S cm −1 without the use of any post-treatment. The good water processability of these conducting polymers is promising for printed electronics in a wide range of applications.

The printing of an efficient thermistor temperature sensor by using self-doped conducting polymers has been achieved. The use of a water-soluble polymer as the active material allows printing and processing in green solvents. The sensor showed a good sensitivity to temperature variations, with a temperature coefficient of resistance (TCR) of -1.3%. The sensor also exhibited a better stability and reversibility towards humidity compared to the state-of-the-art PEDOT:PSS.