New 'nano-positioners' may have atomic-scale...(or voltage. Clark used computational...)

Clark used computational methods called nodal analysis and finite element analysis to design, model and simulate the monolithic comb drives.

The research paper describes how the monolithic comb drive works when voltage is applied. The results show independent left-right and forward-backward movement as functions of applied voltage in color-coded graphics.

The findings are an extension of research to create an ultra-precise measuring system for devices having features on the size scale of nanometers, or billionths of a meter. Clark has led research to create devices that "self-calibrate," meaning they are able to precisely measure themselves. Such measuring methods and standards are needed to better understand and exploit nanometer-scale devices.

The size of the entire device is less than one millimeter, or a thousandth of a meter. The smallest feature size is about three micrometers, roughly one-thirtieth as wide as a human hair.

"You can make them smaller, though," Clark said. "This is a proof of concept. The technology I'm developing should allow researchers to practically and efficiently extract dozens of geometric and material properties of their microdevices just by electronically probing changes in capacitance or voltage."

In addition to finite element analysis, Clark used a simulation tool that he developed called Sugar.

"Sugar is fast and allows me to easily try out many design ideas," he said. "After I narrow down to a particular design, I then use finite element analysis for fine-tuning. Finite element analysis is slow, but it is able to model subtle physical phenomena that Sugar doesn't do as well."

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