Physicists at the University of Arkansas have discovered a new property of graphene that could be exploited to generate endless, clean energy. While investigating the simple phenomenon of graphene’s ability to ripple and shake, physicist Paul Thibado and a group of graduate students uncovered a previously unknown behavior in which the wonder material buckles and twists in small, random fluctuations, potentially allowing graphene to be used as an ambient power source. When two electrodes are added on either side of a subtly shaking sheet of graphene, a small shifting voltage is produced, one that can could be magnified for practical use through layering.
This new discovery was made over the course of a fairly mundane exploration of graphene’s known tendency to jiggle. It is this random movement of atoms that allows the nearly 2D graphene to function as a 3D material. To study this behavior, students laid sheets of graphene on a copper grid and observed the atomic movement through a scanning tunneling microscope. “The students felt we weren’t going to learn anything useful,” said Thibado, “but I wondered if we were asking too simple a question.” The students then searched for a pattern in graphene’s movement. “Looking at large-scale averages hid the different patterns. Each region of a single image, when viewed over time, produced a more meaningful pattern,” said Thibado.
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This meaningful pattern of small, random fluctuations that result in dramatic shifts is known as a Lévy flight. Although the phenomenon had been previously observed in biology and climate studies, this marks the first instance in which it was observed on an atomic level. These movements allowed for the production of a small voltage within the graphene. Thibado estimates that a single ten micron by ten micron piece of graphene may produce ten microwatts of power. While this may not seem like much, graphene’s ability to be layered heavily even in a small space could result in a practical electrical charge, one that may be used to power bioimplants. Thibado is working with the US Naval Research Laboratory to further investigate and develop the concept.
This new discovery was made over the course of a fairly mundane exploration of graphene’s known tendency to jiggle. It is this random movement of atoms that allows the nearly 2D graphene to function as a 3D material. To study this behavior, students laid sheets of graphene on a copper grid and observed the atomic movement through a scanning tunneling microscope. “The students felt we weren’t going to learn anything useful,” said Thibado, “but I wondered if we were asking too simple a question.” The students then searched for a pattern in graphene’s movement. “Looking at large-scale averages hid the different patterns. Each region of a single image, when viewed over time, produced a more meaningful pattern,” said Thibado.
Related: New graphene sieve can remove even small salts from seawater
This meaningful pattern of small, random fluctuations that result in dramatic shifts is known as a Lévy flight. Although the phenomenon had been previously observed in biology and climate studies, this marks the first instance in which it was observed on an atomic level. These movements allowed for the production of a small voltage within the graphene. Thibado estimates that a single ten micron by ten micron piece of graphene may produce ten microwatts of power. While this may not seem like much, graphene’s ability to be layered heavily even in a small space could result in a practical electrical charge, one that may be used to power bioimplants. Thibado is working with the US Naval Research Laboratory to further investigate and develop the concept.