A novel multifunctional soft robotic transducer made with poly (ethylene-co-methacrylic acid) ionomer metal nanocomposite

Reported is realization of a novel ionic electro-active biomimetic soft robotic polymer metal nanocomposite known as poly (ethylene-co-methacrylic acid) metal composite (called EMAMC in this paper) capable of functioning as soft robotic biomimetic actuators, energy harvesters and sensors. By soft robotic it is meant that these materials are easily deformable soft plastics like an elephant trunk. Further reported is the manufacturing methodology of the novel multi-functional electroactive polymer metal nanocomposite EMAMC. The electro-less chemical plating is performed by a chemical REDOX operation on poly (ethylene-co-methacrylic acid) or (PEMAA) ionomer with a metal. PEMAA is a commercially available ionomer commercially known as Surlyn® by DuPont and used for manufacturing golf balls. Surlyn® is a copolymer of ethylene and methacrylic acid groups and is partially neutralized with Na+ ions. To increase the ion exchange capability of Surlyn® the polymer is subjected to a chemical hydrolysis in potassium and sodium hydroxides (KOH, NaOH) and dimethyl sulfoxide (DMSO). This procedure is followed by a chemical REDOX procedure in which PEMAA is first oxidized in a metallic salt solution followed and then reduced in a lithium and sodium borohydride solutions to deposit metallic nanoparticles near boundaries and on the surfaces of hydrolyzed Surlyn®. This REDOX operation creates highly conductive electrodes on and near boundary surfaces. It is then observed that application of a low voltage across the EMAMC causes it to deform softly (actuation mode) with a significant force density and soft bending and deforming the EMAMC will generate electricity (energy harvesting and sensing modes). The preliminary results of actuation and sensing of the EMAMC are reported in this paper.