Bioplastic electromechanical actuators based on biodegradable poly(3-hydroxybutyrate) and cluster-assembled gold electrodes

We present the fabrication and characterization of electroactive actuators based on natural-derived bioplastic able to display reversible bending deformations in response to low intensity electric fields. We used biodegradable poly(3-hydroxybutyrate) (PHB) blended with a suitable ionic liquid to produce freestanding electroactive ionogel layers through a solvent casting process employing non-toxic solvents. The ionogels were provided with compliant cluster-assembled gold electrodes fabricated by means of supersonic cluster beam deposition (SCBD). These metal layers exhibit tailored electrical properties, large surface areas and mechanical resiliency against deformations. The manufactured actuators were characterized in terms of mechanical, morphological, electrochemical and electromechanical properties. We show that the mechanical properties of the ionogels are similar to those of low density polyethylene, while the actuators demonstrated large bending displacement and stable operational durability. Furthermore, due to the use of PHB in combination with a hydrophobic ionic liquid, the actuators did not exhibit hygroscopic behaviour.