Electrically responsive materials based on polycarbazole/sodium alginate hydrogel blend for soft and flexible actuator application

• The ΔG′/G′0 of the SA hydrogels increased with MW of SA.
• The ΔG′/G′0 of the SA hydrogel with ionic crosslinking was the highest at 7.66.
• The ΔG′/G′0 of the SA hydrogel increased with PCB concnetration.
• The highest bending force of the PCB/SA hydrogel was 2.7 mN at 0.1% v/v PCB.

The electromechanical properties, namely the storage modulus sensitivity and bending, of sodium alginate (SA) hydrogels and polycarbazole/sodium alginate (PCB/SA) hydrogel blends under applied electric field was investigated. The electromechanical properties of the pristine SA were studied under effects of crosslinking types and SA molecular weights, whereas the PCB/SA hydrogel blends were studied under the effect of PCB concentrations. The storage modulus sensitivity and bending of the pristine SA as crosslinked by the ionic crosslinking agent were found to be higher than those of the covalent crosslinking. The storage modulus sensitivity and deflection of the SA increased monotonically with increasing molecular weight. The highest electromechanical response of the PCB/SA hydrogel blends was obtained from the blend with 0.10% v/v PCB as it provided surprisingly the highest ever storage modulus sensitivity, (G′ − G′0)/G′0 where G′0 and G′ are the storage modulus without and with applied electric field, respectively, at 18.5 under applied electric field strength of 800 V/mm.