427b Characterization of Biocompatible Polymer Composites

James J. Lee and Gerold A. Willing. Chemical Engineering, University of Louisville, Eastern Parkway, Louisville, KY 40292

Several polymer composites for actuating devices that are responsive to an electric current and also is biocompatible were studied. These composites may be functionally used as actuators in biomedical devices or robotics. Hydrogels, electroactive polymers (EAPs), and gold nanoparticles were utilized in the development of several biocompatible polymer composites. The hydrophilicity, conductivity, response to electric conduction, strain, thermal stability, and degree of cross-linking of several hydrogel and EAP monomers were characterized. The hydrophilic nature of each homopolymer was characterized to determine the how well the material may function as a part of the biocompatible polymer composite. The mechanical response of each homopolymer was characterized by applying an electrical current. Conduction across the EAP and hydrogel polymer may be enhanced, directed, and controlled by doping it with gold nanoparticles. The size, concentration, and distribution of the gold nanoparticles in the EAP and hydrogel monomers were studied. Several combinations of hydrogels and EAPs with the gold nanoparticles were then characterized to develop several electrically actuating biocompatible polymer composites.

Understanding and characterizing the homopolymer and copolymers with and without the gold nanoparticles provided a preliminary step in engineering a system to design and develop an EAP-hydrogel copolymer composite. The characteristics will be used to later develop mathematical relationships between the water solubility and the conductivity of the monomers, EAP-hydrogel copolymers, and EAP-hydrogel copolymer composites. The mathematical models will be used to design a structured, scientific approach to develop an EAP-hydrogel copolymer composite with the desired biocompatible, mechanical, and electrical properties. The potential impact of this polymer composite's characterization and mathematical model may aid in development of various biocompatible EAP-hydrogels for multipurpose uses in artificial muscles, biomimetic robotic machines, sensors and actuators from the macro to the nano scale, and smart materials that can change according to environmental conditions.