Surfaces with dynamically switchable adhesion have a wide range of applications in fields such as robotics and manufacturing. For example, surfaces with switchable adhesion enable new types of gripping surfaces for use in climbing and perching robots. This award supports research to realize a new concept in switchable adhesive surfaces based on the use of composite materials where the stiffness of one component of the material can be changed via the application of an electrical signal. By modulating the stiffness of one component of the composite, the manner in which force is distributed to the interface is altered, and as a result, the effective adhesion strength of the interface is changed. The underlying adhesion mechanics of these materials will be established through modeling and experiments, thus enabling the optimized design of composite structures with dynamically switchable adhesion. This project is a collaboration between researchers at the University of Nevada, Reno and the University of Pennsylvania and will result in the training of students in advanced materials, mechanics, manufacturing, and soft robotics, thus contributing to the development of the engineering workforce in the U.S.
The research will realize new composite materials with dynamically tunable adhesion through a research plan that includes the design, fabrication, and characterization of two classes of elastomer-based composite materials with high dry adhesion strength. Finite element-based multiphysics models will be used to investigate the how the structure of the composite and the stiffness heterogeneity contribute to the effective adhesion strength. Scalable routes to realize flat and fibrillar surfaces made of these composite materials will be developed by leveraging microfabrication techniques and recent manufacturing advances from the field of soft robotics and electronics. Characterization efforts will focus on establishing: (1) the mechanical and adhesion properties of the constituent materials in order to inform the modeling and simulation effort, and (2) the adhesion properties and performance of the novel composite material systems that are fabricated. This research will lead to an improved fundamental understanding of the mechanics and manufacturing of composite material systems with tunable adhesion.
