The enhancement is completely reversible
One of the remarkable aspects of the effect Li discovered is that it is reversible. For example, when the researchers wetted the interface of a pair of nanoribbons with isopropyl alcohol, pressed them together and let them dry, the thermal conductivity was the same as that of a single nanoribbon. However, when they wetted them with pure alcohol and let them dry, the thermal conductivity was enhanced. Then, when they wetted them with isopropyl alcohol again, the thermal conductivity dropped back to the original low value.
"It is very difficult to tune a fundamental materials property such as thermal conductivity and the demonstrated tunable thermal conductivity makes the research especially interesting," Walker said.
One of the first areas where this new knowledge is likely to be applied is in thermal management of microelectronic devices like computer chips. Today, billions to trillions of transistors are jammed into chips the size of a fingernail. These chips generate so much heat that one of the major factors in their design is to prevent overheating. In fact, heat management is one of the major reasons behind today's multi-core processor designs.
"A better understanding of thermal transport across interfaces is the key to achieving better thermal management of microelectronic devices," Li said.
Discovery may improve design of nanocomposites
Another area where the finding will be important is in the design of "nanocomposites" materials made by embedding nanostructure additives such as carbon nanotubes to a host material such as various polymers that are being developed for use in flexible electronic devices, structural materials for aerospace vehicles and a variety of o
|Contact: David F Salisbury|