His project, “Deformation and interfacial slip in two-dimensional material heterostructures,” focuses on examining and understanding the mechanics at the interfaces between nanomaterials and how to take advantage of the emergent properties to engineer highly deformable electromechanical devices.
In the last 50 years, solid state nanotechnology has brought devices—such as transistors, solar cells, and microelectromechanical systems—which allow integrated computation, energy harvesting, sensing, and communication, and have become ubiquitous in our daily lives. Yet nature offers another nanotechnology, based on soft materials, with capabilities far exceeding human-engineered systems. For example, cells are capable of self-assembly into complex molecular systems that are three-dimensional, dynamic, reconfigurable, responsive to their environment, and self-sustaining. A grand challenge for the next century is to unite these disparate nanotechnologies to fundamentally transform the way we interact with electronics.
The driving vision in van der Zande’s work is to push mechanics to its ultimate limits in size to bring the unique capabilities of soft materials to electronic systems. This work has applications in many technologies, from stretchable and wearable electronics, to low-power, highly-sensitive biosensors, to origami nano machines capable of interacting with cells.
The CAREER grant will allow van der Zande to explore the mechanics and applications of 2D materials like graphene and molybdenum disulfide, which are stable crystals that are only one molecule thick—like a very thin sheet of paper. These materials, then, are a perfect material foundation for many new technologies. When layered on top of each other, they form heterostructures. (Imagine a stack of papers with different colors.) Because the 2D materials are stable on their own but each layer has a different structure, the heterostructures are held together by weak van der Waals forces that allow them to slip at the interface between them without breaking bonds. This gives these heterostructures a new and useful property known as superlubricity.
Superlubricity refers to extremely low coefficients of friction that are on the scale of one percent of the lowest frictions that can be engineered otherwise. While superlubricity has been studied for years in tribology, van der Zande’s research will explore a new regime by investigating the mechanics of slip at the interfaces in the atomically thin heterostructures. He also plans to examine how slip affects the mechanics and stiffness of the heterostructures by looking at the shape of crumpled membranes, and the resonant frequencies of suspended membranes.
“We can stretch these heterostructures out like drum heads, resonate them and observe the resonant frequencies—just like a drum but now it’s an atomically thin drum. With that we can precisely probe the mechanics of the interface by looking at how the frequency changes as the layers slip past each other.”
The success of this study will lead to the design of electronic materials that actively utilize slip and deformation to become ten to 100 times more pliable than conventional stretchable materials.
Undergraduate and graduate students in van der Zande’s lab will work on the project, as well as help van der Zande with an outreach program in which students in schools and summer camps from underrepresented groups can build laser light shows.
“The CAREER award is great for the early stages of my research program to start exploring new ideas that I have been thinking about for a while but not had the opportunity to pursue.”