Experimental Measurement of the Hamaker Constant

in 1973, Tabor and Israelachvili developed a surface force apparatus, SFA, to measure the interaction force in a vacuum at the 1.5 nm level for the first time. In this equipment, the interaction forces between two crossed cylinders coated with freshly cleaved mica sheets having atomically smooth surfaces were measured. One of the cylinders is mounted on a piezoelectric transducer, and the other cylinder is mounted on a spring of known and adjustable spring constant with a force resolution down to 1CT8N. SFA has been further developed for performing measurements in liquids and vapors. In these developed SFA versions, the separation distance between the cylinders can be measured interfero- 

Atomic force microscopy, AFM, which was developed in the 1980s is also used for interaction force measurement between surfaces. In AFM, the force between the micro-fabricated tip, which is placed at the end of an approximately 100/fln long and 0.5-5 jtim thick cantilever, with another surface is measured however this force is usually too small 

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