We present a new approach to the fabrication of soft dielectric elastomer actuators using a 3D printing process. Complete actuators including active membranes and support structures can be 3D printed in one go, resulting in a great improvement in fabrication speed and increases in accuracy and consistency. We describe the fabrication process and present force and displacement results for a double-membrane antagonistic actuator. In this structure controlled prestrain is applied by the simple process of pressing together two printed actuator halves. The development of 3D printable soft actuators will have a large impact on many application areas including engineering, medicine and the emerging field of soft robotics.
We present a self-motivating and self-switching bistable structure using bending actuators or artificial muscles. By exploiting the inherent bi-stability in buckled beam and buckled plate structures we have designed a bistable actuator that requires no energy to maintain either of the two stable states. In addition to bistable characteristics we show how such a structure, if constructed from a bending actuator (artificial muscle) such as ionic polymer metal composites (IPMC), may actively switch itself between stable states. Thus the self-switching bistable actuator is an extremely simple and elegant design that requires none of the external actuating mechanics traditionally used. In the analysis we consider the nature of bistable buckled beams and their internal stresses and we propose actuating schema for the movement from one stable state to another. We show how segmentation of a strip actuator can be matched to the desired bistable structure and the intended switching motion. We consider the characteristic buckling modes of axially compressed beams and show how these can suggest efficient control and switching mechanisms. We also present some example applications from the micro-scale upwards, including a tactile display device.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.