| Citation | Distinguished for a long and remarkable varied series of important advances in physical electronics, above all for his invention of the acoustic microscope and the atomic force microscope.
The idea of using ultrasonic waves for microscopy, though previously considered, came to fruition in 1974, when Professor Quate invented the acoustic microscope, based on the use of a solid-liquid interface lens. The basic concept is (with hindsight) simple: -it is based on the fact that the large differences in acoustic velocities in different materials allow almost aberration free imaging with a single refractive interface. Professor Quate and his students rapidly obtained a resolution of a few microns, then exceeded that obtainable with optical microscopes and eventually (using liquid He as a coupling medium) achieved a resolution of 200A. The acoustic microscope, which is now commercially available from several manufacturers, depends on contrast mechanisms which differ from those used in other forms of microscopy; it has developed into an important modality, particularly for biological specimens.
In the early 1980's Quate immediately appreciated the power of the scanning tunnelling microscope, invented by Binnig and Rohrer. But he also noted the unfortunate fact that this remarkable instrument could not be used on insulating specimens. It was this thought which led him, together with Binnig and Gerber to invent the Atomic Force Microscope, (AFM), which has proved to be of such vital importance in biological, superconductivity, electro-chemistry and surface sciences. Professor Quate was also amongst the first to exploit the AFM for surface modification at the molecular and atomic levels and to appreciate the potential for the realisation of an atomic scale memory. In addition to demonstrating pioneering applications of the AFM, Professor Quate and his co-workers have made major advances in developing ever simpler and yet more powerful instruments - for example by the use of piezo electric displacement detection.
Whilst it is inevitable that his remarkable contributions to microscopy must dominate any account of his achievements, he had attained world fame before he embarked on acoustic microscopy - inter alia for his work on electron beam devices, and for the invention of the acoustic wave correlator. There is no sign of any end to his inventiveness - for example his work on the use of acoustic radiation pressure as the operating principle for an ink jet printer. Scanning the titles of the 57 patents reveals both the breadth of Professor Quate's work and its undiminished creativity. |