Researchers at the University of Illinois Urbana-Champaign, under the guidance of Professor Rosa Espinosa-Marzal from the Department of Civil and Environmental Engineering, have made a significant breakthrough in the field of friction control. Their findings, outlined in a paper titled “Dynamically tuning friction at the graphene interface using the field effect,” published on September 19, 2023, in the esteemed journal Nature Communications, shed light on the ability to manipulate friction on a surface composed of graphene by employing external electric fields.
Graphene, a single layer of carbon atoms arranged in a honeycomb lattice, has gained recognition for its exceptional mechanical, electrical, and thermal properties. It is regarded as a promising material for various applications, ranging from electronics to energy storage. However, understanding and controlling the behavior of friction on graphene surfaces has remained a challenge until now.
In this study, Professor Espinosa-Marzal and her team explored the concept of dynamically adjusting friction on a graphene surface by utilizing external electric fields. By subjecting the graphene surface to varying electric field strengths, they observed that the friction could be actively modulated.
The researchers conducted their experiments by placing a flat indenter on the graphene surface and measuring the resulting frictional forces as electric fields were applied. They discovered that when an electric field was introduced perpendicular to the graphene surface, the frictional forces experienced a notable reduction. Conversely, when the electric field was parallel to the surface, the friction increased.
This striking observation opens up new possibilities for controlling friction on graphene-based materials. By manipulating the electric field strength, it becomes feasible to dynamically fine-tune the level of friction experienced by objects interacting with graphene surfaces. This capability holds great potential for numerous applications requiring precise friction control, such as the development of advanced lubricants or the design of nanoelectromechanical systems.
Moreover, the researchers extended their investigation beyond pure mechanical friction. They examined how the electric fields affected the interfacial water molecules present on the graphene surface. Surprisingly, they found that the electric field influenced the bonding between water and the graphene surface, consequently altering the friction experienced by the indenter.
Understanding the underlying mechanisms of friction control on graphene surfaces is crucial for optimizing the performance of graphene-based devices and materials in various industries. Professor Espinosa-Marzal’s team hopes that their groundbreaking research will pave the way for further advancements in this field, leading to the development of novel applications that capitalize on the unique properties of graphene.
In summary, the recent study conducted at the University of Illinois Urbana-Champaign reveals the exciting ability to dynamically manipulate friction on a graphene surface using external electric fields. This breakthrough has significant implications for diverse fields, ranging from materials science to nanotechnology, where precise control over friction is essential. The findings contribute to our understanding of graphene’s behavior and open up new avenues for harnessing its potential in practical applications.
