Recent advances in development of bio-mimicking material systems coupled with advanced manufacturing techniques can open new avenues in creation of bio-inspired soft matter devices. To this end, this work focuses on exploration of 3D printing ionic hydrogel-elastomer hybrid material system for fabrication of soft, electrically driven actuators as a fundamental basis for bio-inspired actuation. The 3D printed devices have a unimorph configuration comprising an electroactive polymer which is inserted between two layers of soft, stretchable ionic hydrogel as the electrodes, and attached to a stiffer passive layer. Specifically, a silicone-based dielectric elastomer material has been used as the electroactive component of the device that exhibits mechanical deformation in response to applied electrical stimuli. The composition of the silicone elastomer has been optimized for printability, as well as improved dielectric functionality and electromechanical sensitivity. Furthermore, a printable, stretchable, ionic hydrogel has been applied as the compliant electrodes of the soft actuators. Such ionically conductive hydrogels have recently attracted a growing interest in development of soft active devices due to their favorable properties, including high stretchability and mechanical integrity, and their capability to function at high applied voltages and frequencies. Finally, by incorporating effective surface engineering strategies to overcome the material incompatibilities, the layered structure of the soft actuators has been 3D printed via the direct ink writing technique. Upon the application of electrical fields, the in-plane expansion of the active dielectric layer is translated to an out-of-plane bending motion due to the restriction imposed by the passive layer. The performance of final devices has been characterized in response to different types of electrical stimuli and modeled using finite element method and analytical formulations. The outcomes of this works can pave the path for advanced manufacturing of nature-mimicking systems for soft-matter applications, including soft robots, with complex geometries and integrated functionalities.

3D-printed, electrically-driven soft actuators based on hydrogel-elastomer hybrids

2019 Spring National Meeting

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.