Calvin Quate

Calvin Quate — inventor of scanning acoustic and atomic force microscopes

Calvin “Cal” Quate is the brilliant mind behind acoustic and atomic force microscopy. The scanning acoustic microscope, invented with a colleague in 1973, has resolution exceeding optical microscopes, revealing structure in opaque or even transparent materials that are invisible to optics.

Quate received his PhD from Stanford in 1950 and joined the faculty in 1961. Today he is a Stanford professor emeritus of electrical engineering and applied physics.

In 1985, Quate read about a new type of microscope that could examine electrically conductive materials. When dreamed up a related instrument that would work on non-conductive materials — including biological tissue — the atomic force microscope (AFM) was born. AFM traces surface contours using a needle to maintain constant pressure against the surface to reveal atomic detail. AFM is the foundation of the $100 million nanotechnology industry.