Working at the nanoscale often presents new challenges for researchers, such as dealing with forces that aren't an issue at the microscale. Researcher Narayana Aluru of the Molecular and Electronic Nanostructures Research Initiative is answering those challenges by offering the first physical theory for modeling nanoelectromechanical (NEMS) systems. Aluru is publishing a series of papers, including one in the June issue of the Journal of Applied Physics, that address these issues in this new but rapidly growing field.
Classical theories of physics, such as those for microelectromechanical systems, often don't apply at the nanoscale. Aluru and his group are filling the void by developing physical theories and computational design tools to aid in the modeling of nanoscale structures and systems.
"Basically when you go to nanoscale what happens is you see new physics," Aluru said. "So when you make these mechanical structures really small the way they behave may not be described by classical theory."
Aluru and his students are developing new theories, including the first ones to combine quantum mechanical theories for electrostatics with nanoscale mechanics. In the June 1 issue of the Journal of Applied Physics Aluru and graduate students Zhi Tang, Yang Xu, and research scientist Gang Li reported on "Physical models for coupled electromechanical analysis of silicon nanoelectromechanical systems."
The paper addresses problems - such as the influence of van der Waals forces that are usually not a factor at the microscale - by describing the mechanical, electrical, and van der Waals energy domains and the effects of coupling, or feedback, at the nanoscale. Accounting for this feedback can make for some time-consuming and expensive computational work.
"What we have done, because the classical treatment of van der Waals is very expensive, is develop a continuum-based theory so we can do this thing much, much quicker," Aluru said.
Aluru said NEMS is a new field, with the first papers published within the last decade. For more on this pioneering Beckman Institute research, please read the full text of the paper by clicking on the title above.