With the help of laser light, researchers have developed an atomic force microscope that is ultrastable under ambient conditions, and could be useful for a range of new applications in single-molecule biophysics and nanomanufacturing. Atomic force microscopy (AFM) applications are often limited by mechanical drift between the probe tip and the sample, which makes it difficult to monitor a specific feature on a surface over time. Researchers have been able to minimize drift under ultrahigh vacuum or cryogenic conditions, but these environments aren't conducive to biological studies or nanomanufacturing. Now, a team led by Thomas T. Perkins from JILA, a precision physics lab run jointly by NIST and the University of Colorado, Boulder, scattered a laser off the apex of a commercial AFM tip and added a second laser to create a stable, optically based frame of reference (Nano Lett., DOI: 10.1021/nl803298q). The team controlled the tip's position with high precision in air at room temperature over more than one hour, and increased the signal-to-noise ratio of their AFM images fivefold.

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