HIGH-SPEED ATOMIC-FORCE MICROSCOPY USING AN INTEGRATED ACTUATOR AND OPTICAL-LEVER DETECTION

A new procedure for high-speed imaging with the atomic force microscop e that combines an integrated ZnO piezoelectric actuator with an optic al lever sensor has yielded an imaging bandwidth of 33 kHz. This bandw idth is primarily limited by a mechanical resonance of 77 kHz when the cantilever is placed in contact with a surface. Images scanned with a tip velocity of 1 cm/s have been obtained in the constant force mode by using the optical lever to measure the cantilever stress. This is a ccomplished by subtracting an unwanted deflection produced by the actu ator from the net deflection measured by the photodiode using a linear correction circuit. We have verified that the tip/sample force is con stant by monitoring the cantilever stress with an implanted piezoresis tor. (C) 1996 American Institute of Physics.