By Jenice Con Foo, Ph. D., Mad City Labs, Inc.
Achieving precision motion at the micron level is an impressive feat: a carefully choreographed waltz of experiment design, instrumentation, and a keen eye for detail. It stands to reason that progressing to nanometer-level precision would simply be a matter of refining a few steps. However, controlling motion at the nanoscale is a completely different dance.
Consider an experiment in optical microscopy. A researcher may think, justifiably, that their micron-level experiment setup and instrumentation allow for precise control. Simply adding a nanopositioner will allow them to go the last mile in terms of motion control: to take thinner slices of their sample and to locate more minute areas of interest within the sample. But researchers may not realize that sample image details are not the only thing magnified; minor issues at the micron scale can be devastating at the nanometer scale.
Suddenly, things are not as focused as expected or everything seems to be moving. In fact, everything probably has been moving the whole time; the researcher just lacked the technical capability to observe that movement. In this respect, progressing from the micron scale to the nanoscale is like wearing a new pair of glasses.
What Factors Affect Precision Motion at Nanometer Scale?
A common misconception surrounding nanoscale motion is that precision depends solely on instrumentation — specifically, securing equipment with a technical specification of nanometer resolution. But any experiment’s metrology loop must also account for thermal expansion, force distortion, misalignments, and other passive factors that affect both instrumentation and the experiment. The instrumentation a researcher chooses is part of passive controls, while passive factors include acoustic effects and thermal control of a workspace.