The electron microscope revolutionized biology in the 1930s by providing magnifications thousands of times higher than that of light microscopes, allowing scientists to discern the inner workings of cells for the first time.

But it was not nearly as helpful for materials scientists such as the ones constructing electronic circuits, who were more interested in surfaces. Exploring the details of those circuits required a completely new technology, the scanning tunneling microscope, which would provide images of individual atoms on surfaces.

Many scientists thought such a feat impossible. In 1979, however, physicists Heinrich Rohrer and Gerd Binnig of the IBM Research Laboratory in Zurich, Switzerland, patented such a device and forever changed the electronics industry. For their invention, they received the 1986 Nobel Prize in physics, an award they shared with physicist Ernst Ruska, who designed the first electron microscope.

Rohrer and Binning were known as the fathers of nanotechnology the construction and manipulation of extremely small objects because their device could be used to move atoms around on a surface.

Rohrer died of natural causes May 16 at his home in Wollerau, Switzerland, according to IBM. He was 79.

"The invention of the scanning tunneling microscope was a seminal moment in the history of science and information technology," John E. Kelly III, director of research at IBM, said in a statement. "This invention gave scientists the ability to image, measure and manipulate atoms for the first time, and opened new avenues for information technology that we are still pursuing today."

The pair's invention relies on a quantum-mechanical phenomenon known as tunneling, so called because the electrons pass through a supposedly impenetrable barrier, such as a vacuum. The phenomenon is the basis of scanning tunneling microscopy.

In tunneling, the tip of an electrically charged wire, for example, emits electrons in waves that roughly resemble the shape of a fountain. When two such devices are brought closely together, the overlapping waves partially merge and electrons flow through the gap, creating a small current.

Their device uses a stylus not unlike the needle of a record player. It is much smaller, however, converging to a point only one atom in diameter. In a high vacuum, the needle is brought close to the surface to be examined and a small electric charge applied, producing a current. The strength of the current depends on the distance between the point and the surface.

As the stylus is scanned back and forth across the surface much like the electron beam of a cathode ray tube in a television the current varies with the height of the surface. A computer moves the stylus up and down to keep the current constant. The record of those movements, converted into two dimensions, provides an image of the surface. The entire process relies on the current produced by tunneling.

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Heinrich Rohrer dies at 79; a father of nanotechnology