Patent ID: 7607343

Claim:
A scanning probe microscope system comprising: a microelectromechanical system actuator operable to move a flexible cantilever mechanically coupled to a probe tip; an optical detector optically coupled to said flexible cantilever; a controller, said controller electrically coupled to said microelectromechanical system actuator and electrically coupled to said optical detector; and an estimator having an estimator feedback gain, said estimator electrically coupled to said optical detector and electrically coupled to said controller where said estimator is operable to receive an error signal from said optical detector and operable to use said error signal and said estimator feedback gain to generate a state estimate, said state estimate output to said controller, said controller operable to provide a control signal to said microelectromechanical system actuator to maintain a deflection of said flexible cantilever at an approximately constant value, wherein said control signal depends on said state estimate.