Power-efficient and precise raster scanning of piezoactuated stages for high-speed atomic force microscopy

High-speed atomic force microscopes (AFMs) greatly improve the imaging throughput compared to conventional AFMs. However, their piezoelectrically actuated raster-scanning stages demand much larger currents and generate high inertial forces that can excite spurious vibrations. This paper proposes the use of a passive electrical network in Foster's Type-II form to greatly reduce the current demand, and a strategy for in situ calibration and subsequent pre-compensation to eliminate the effect of spurious vibrations. A systematic approach is proposed for the design of the network. The performance of the network is numerically and experimentally validated for a three-branch design that achieves zero susceptance at 2, 6, and 10 kHz. The network is experimentally demonstrated to achieve more than a four-fold reduction in the current supplied by the source when the piezo is actuated by a triangular raster-scanning waveform of 2 kHz frequency is provided. The proposed pre-compensation strategy is also experimentally demonstrated to result in over four-fold better following of the triangular waveform compared to the case without it.