A lead researcher from the Sandia National Laboratories is asserting that nanoscience computer simulations are a better scientific tool than experiments:
Taking issue with the perception that computer models lack realism, a Sandia National Laboratories researcher told his audience that simulations of the nanoscale provide researchers more detailed results – not less – than experiments alone.
The invited talk by Eliot Fang was delivered to members of the Materials Research Society at its recent semiannual general meeting.
Sandia is a National Nuclear Security Administration laboratory.
Fang derided the pejorative “garbage in, garbage out” description of computer modeling – the belief that inputs for computer simulations are so generic that outcomes fail to generate the unexpected details found only by actual experiment.
Fang not only denied this truism but reversed it. “There’s another, prettier world beyond what the SEM [scanning electron microscope] shows, and it’s called simulation,” he told his audience. “When you look through a microscope, you don’t see some things that modeling and simulation show.”
This change in the position of simulations in science – from weak sister to an ace card – is a natural outcome of improvements in computing, Fang says. “Fifteen years ago, the Cray YMP [supercomputer] was the crown jewel; it’s now equivalent to a PDA we have in our pocket.”
No one denies that experiments are as important as simulations – “equal partners, in fact,” says Julia Phillips, director of Sandia’s Physical, Chemical, and Nanosciences Center.
But the Labs’ current abilities to run simulations with thousands, millions, and even billions of atoms have led to insights that would otherwise not have occurred, Fang says.
For example, one simulation demonstrated that a tiny but significant amount of material had transferred onto the tip of an atomic force microscope (AFM) as it examined the surface of a microsystem.
“The probe tip changed something very, very tiny on the surface of the material,” says Fang. “It was almost not noticeable. But the property of the surface became very different.”
Laboratory observation couldn’t identify the cause of the property change, but computer simulations provided a reasonable explanation of the results.
As for predicting the reliability of materials that coat surfaces, Fang says, “We find that when we compare our simulation models with data from the experiments, we get a more complete understanding.”
Says Sandia Fellow and materials researcher Jeff Brinker, “We use simulations quite a bit in support of Sandia’s water purification program and the NIH Nano-Medicine Center program. In all these cases I’m working with theorists and modelers to guide the design of synthetic nanopores so as to develop transport behaviors approaching those of natural water or ion channels that exist in cell membranes.”
Read more at Sandia NL press office…