Control of microcantilevers in dynamic force microscopy using time delayed feedback

It has been recently shown that microcantilever sensors in dynamic force microscopes possibly exhibit chaotic oscillations due to the nonlinear tip-sample interaction force. In this article, we propose elimination of the chaotic oscillations using the time delayed feedback control method, which has an ability to stabilize unstable periodic orbits embedded in chaotic attractors. An extended operating range of the microscopes is numerically estimated by stability analysis of the target periodic oscillation. We also discuss an improved transient response of oscillation, which allows us to accelerate the scanning rate of the microscopes without reducing their force sensitivity. (c) 2006 American Institute of Physics.