Podcasts by Scanning Tunneling Microscope - How Nanoscientists see Atoms

To see how a Nanosurf easyScan STM works, let's take it apart in virtual reality. from 2021-01-31T22:10:42.023393

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The heart of the STM is an atomically sharp probe. from 2021-01-31T22:10:42.023393

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A voltage induces electrons to jump from the probe's tip to the sample atoms. from 2021-01-31T22:10:42.023393

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But how can it move the probe over these tiny nanometer distances? from 2021-01-31T22:10:42.023393

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Voltages to a piezoelectric crystal move the probe in and out. from 2021-01-31T22:10:42.023393

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Another crystal moves it side to side. from 2021-01-31T22:10:42.023393

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A third crystal moves it up and down. from 2021-01-31T22:10:42.023393

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Let's see how these work together to create an atomic scale map of the sample surface. from 2021-01-31T22:10:42.023393

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The voltage to the back crystal determines pixel color. Voltages on the other crystals move the probe and pixels side-to-side and up-and-down. from 2021-01-31T22:10:42.023393

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But how do we first position the probe only a nanometer or so from the sample surface? from 2021-01-31T22:10:42.023393

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It's done by ratcheting this cylinder in until an electron current is sensed. from 2021-01-31T22:10:42.023393

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This STM is so simple that we use it in UVA classes. But it also earned two physicists the Nobel Prize in 1986. from 2021-01-31T22:10:42.023393

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All of the scenes together from 2006-05-11T11:59

All of the scenes together from 2006-05-11T11:59