Mechanical engineering's Grunlan co-authors paper in Science

Dr. Jaime C. Grunlan, associate professor in the Department of Mechanical Engineering, has co-authored a paper in the journal Science that is part of an international research collaboration with faculty in the Centre for Research on Adaptive Nanostructures and Nanodevices (CRANN) at Trinity College Dublin, Ireland, and the University of Oxford.

Photo of Dr. Jaime Grunlan

In the paper, "Two-Dimensional Nanosheets Produced by Liquid Exfoliation of Layered Materials," principal investigators Dr. Jonathan Coleman of Trinity College Dublin and Dr. Valeria Nicolosi of Oxford explain a new way of splitting layered materials to give atom thin "nanosheets." This discovery has led to a range of novel two-dimensional nanomaterials with chemical and electronic properties that have the potential to enable new electronic and energy storage technologies.

The scientists have invented a versatile method for creating these atom thin nanosheets from a range of materials using common solvents and ultrasound, utilizing devices similar to those used to clean jewelry. The new method is simple, fast and inexpensive, and could be scaled up to work on an industrial scale.

Grunlan said, "My Ph.D. student Greg Moriarty did some measurements on films produced in Coleman's lab to show that they exhibit thermoelectric behavior (i.e., could convert heat into electricity). We were approached by Dr. Coleman because we already have a reputation for producing novel thermoelectric materials."

For decades researchers have tried to create nanosheets from layered materials in order to unlock their unusual electronic and thermoelectric properties. However, previous methods were time consuming, laborious or of very low yield and so unsuited to most applications.

"Our new method offers low-costs, a very high yield and a very large throughput: Within a couple of hours, and with just 1 mg of material, billions and billions of one-atom-thick nanosheets can be made at the same time from a wide variety of exotic layered materials," Nicolosi said.

These new materials are also suited for use in next generation batteries - "supercapacitors" - which can deliver energy thousands of times faster than standard batteries, enabling new applications such as electric cars. Many of these new atomic layered materials are very strong and can be added to plastics to produce super-strong composites. These will be useful in a range of industries from simple structural plastics to aeronautics.