Development of high sensitive polyaniline based piezoresistive films by conventional and green chemistry approaches

Conductive polymers are gaining increasing interest due to their large range of applications as sensing materials. Among them, polyaniline (PANI) is a promising candidate and this work demonstrated its excellent piezoresistive properties when it is doped with dodecylbenzenesulfonic acid (DBSA) and camphorsulfonic acid (CSA) and processed as films. Two types of PANIs were synthesized by two different routes: a traditional method (PANI1), based on the use of a stoichiometric oxidant; and an environmentally friendly approach (PANI2), based on a catalytic procedure. The relationship between electromechanical response and morphology was investigated, as well as the stability of the piezoresistive sensing performance. Extraordinary high gauge factors were obtained, reaching values up to 100. Overall, it was demonstrated the suitability and large potential application of these materials as force and deformation sensors.