Atomic Force Microscope

allow imaging of non-conducting surfaces down to the sub-nanometer level without the need for any additional sample preparation. The AFM consists of a sharp tip (10-20 nm diameter) attached to a stiff cantilever. The tip is brought close to the surface and the sample is scanned beneath the tip. The tip moves in response to tip-surface interactions, and this movement is measured by focusing a laser beam onto the back of the cantilever and detecting the position of the reflected beam with a photodiode.