NRI: FND: Smart Material Composites and Design of Internal Structural Geometry for Tunably Compliant Soft Robots

Washington State University, Pullman WA

Investigators

Abstract

This project will demonstrate soft robots that can radically modulate their stiffness in a manner comparable to biological systems. This ability will enable robots that can safely collaborate with human co-workers in the service and manufacturing industries. The creation of intrinsically flexible robots using materials such as soft rubbers and foams is a stark contrast to the traditional paradigm of large, heavy, rapidly moving robotics in isolated environments, and has played an important role towards moving robots from the factory floor to the home, clinic, and office. However the intrinsic compliance that makes soft materials safe also makes them unable to exert large forces or to maintain their shape when acted upon by outside forces. In many biological systems, animals are able to change the magnitude and directionality of their soft tissue stiffness through muscle contractions and modification of internal fluid pressures. This project will show researchers how to use controllable compliance in robotic components to obtain the benefits of soft materials -- adaptability, fault tolerance, and safety -- while also providing greater force and manipulation capabilities. The results will find application in a wide range of applications, including home health care, medical interventions, factory automation, and disaster response. The simplicity and safety of experimental exploration with soft robotics also provides an ideal platform for high schools students and undergraduate students to get involved in the emerging field of soft robotics. The central hypothesis of this research is that the development of tunable compliance - with respect to location, magnitude, and directionality - will provide greater dexterity and control and allow soft robotic designs to exert larger and more precise forces on their environment. This work will research the effects of compositing smart materials with existing soft robotic components to identify the fundamental principles of geometric design of the smart material aggregate. The intention is to imbue soft robots with the ability to dynamically adjust the magnitude, spatial location, and directionality of their compliance. These three aspects of tunable compliance will require new methods of modeling kinematics and dynamics as a function of the control of the smart material stimuli, in conjunction with other traditional actuation schemes such as tendons and pneumatics. Another primary result of the project will be quantitative metrics to objectively describe the capabilities of the resulting tunably compliant robots, in order to formally optimize the geometry of the smart material aggregate.