Mechatronic Demodulation of AFM Cantilever Oscillation
In Atomic Force Microscopy, an oscillating microcantilever with a sharp tip is used to measure local mechanical or electrical surface properties with nanometer resolution. In state of the art systems, expensive external lock-in demodulators are required to determine the amplitude and phase of the cantilever oscillation. We have developed a technology which allows a direct measurement of self-sensing AFM cantilever oscillations. The method enables demodulation without expensive external components and uses high frequency sensor supply voltages to avoid electrochemical reactions during operation in liquids.