AFM probe developed for [M.sup.3].A new type of probe has been developed for the molecular measuring machine ([M.sup.3]) that allows the imaging of non-conductive samples. [M.sup.3], a one-of-a-kind instrument designed to measure to nanometer accuracy the positions of features located anywhere within a 50 mm x 50 mm area, was developed at NIST (National Institute of Standards & Technology, Washington, DC, www.nist.gov) The standards-defining agency of the U.S. government, formerly the National Bureau of Standards. It is one of three agencies that fall under the Technology Administration (www.technology. . It has been a long-standing plan for [M.sup.3] to eventually add an atomic force microscope atomic force microscope (AFM), device that uses a spring-mounted probe to image individual atoms on the surface of a material. Unlike the scanning tunneling microscope, which is also a scanning probe microscope, the AFM can be used on materials that do not conduct (AFM (Atomic Force Microscope) A device used to image materials at the atomic level. AFMs are used to solve processing and materials problems in electronics, telecom, biology and other high-tech industries. ) probe to increase the variety of samples that can be measured. Now, with the help of a NIST associate from the Ilmenau Technical University in Ilmenau, Germany, it has been accomplished. Since [M.sup.3] operates in a vacuum environment, and because the space available for the probe is very limited, it was impractical to use a typical, commercial AFM probe that senses the force by measuring the deflection deflection /de·flec·tion/ (de-flek´shun) deviation or movement from a straight line or given course, such as from the baseline in electrocardiography. de·flec·tion n. 1. of a cantilever using an optical-beam, lever arm. Instead, researchers implemented an AFM probe based on measuring the shift in resonant frequency resonant frequency, n the specific frequency at which an object vibrates. of a tuning-fork sensor when a mounted tip comes into the force-interaction zone of the sample surface. For this scheme, the needed probe hardware is minimal, there are no critical alignment issues, and the same pre-amplifier that is normally used for sensing the tunneling current when using the scanning tunneling microscope scanning tunneling microscope, device for studying and imaging individual atoms on the surfaces of materials. The instrument was invented in the early 1980s by Gerd Binnig and Heinrich Rohrer, who were awarded the 1986 Nobel prize in physics for their work. probe can be used to amplify the tuning-fork signal. The first images recently have been acquired using this tuning-fork AFM probe. CONTACT: John Kramar, (301) 975-3447; john.kramar@nist.gov. |
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