Experimental determination of scanning probe microscope cantilever spring constants utilizing a nanoindentation apparatus

A rapid, nondestructive, and accurate method for determining the normal spr ing constants of scanning probe microscopy cantilevers is presented. Spring constants are determined using a commercial combination atomic force micro scope and nanoindentation apparatus configured with a W-indenter tip geomet rically configured into either a scanning tunneling microscope pointed tip or chisel shape that may be placed onto the cantilever of interest with hig h accuracy. A load is applied to the cantilever tip and the corresponding d isplacement is measured. From the force-displacement curve, the spring cons tant is determined. For cantilevers with spring constants greater than 1 N/ m, the derived spring constants are believed to be accurate to within +/- 1 0%, with better accuracy for stiffer levers. This method has been used to m easure the stiffness of cantilevers from several manufacturers. (C) 2000 Am erican Institute of Physics. [S0034-6748(00)01010-8].