Abstract: A linear elastic modulus measurement method and a linear elastic modulus measurement device can reduce external disturbances such as oscillation and electrical noise, and accurately and stably measure the linear elastic modulus of a linear elastic body even in the case where damping due to viscous stress is large. The measurement device computes the oscillation velocity (dx/dt) of an oscillator from the displacement of the oscillator brought into contact with the linear elastic body, and multiplies dx/dt by a linear velocity feedback gain to generate a feedback control signal. The measurement device applies, to the oscillator, a force proportional to the oscillation velocity of the oscillator by the feedback control signal, to cause the oscillator to self-oscillate. The measurement device computes the linear elastic modulus of the linear elastic body from the frequency when the self-oscillation of the oscillator is detected and the mass of the oscillator.

Abstract: A linear elastic modulus measurement method and a linear elastic modulus measurement device can reduce external disturbances such as oscillation and electrical noise, and accurately and stably measure the linear elastic modulus of a linear elastic body even in the case where damping due to viscous stress is large. The measurement device computes the oscillation velocity (dx/dt) of an oscillator from the displacement of the oscillator brought into contact with the linear elastic body, and multiplies dx/dt by a linear velocity feedback gain to generate a feedback control signal. The measurement device applies, to the oscillator, a force proportional to the oscillation velocity of the oscillator by the feedback control signal, to cause the oscillator to self-oscillate. The measurement device computes the linear elastic modulus of the linear elastic body from the frequency when the self-oscillation of the oscillator is detected and the mass of the oscillator.

Abstract: The oscillating velocity of an oscillating body in a fluid to be measured is positively fed back, so as to activate an actuator. The oscillating state of the oscillating body is monitored while making a velocity feedback gain increase. The velocity feedback gain when the oscillating body has oscillated is obtained as an oscillation limit gain at the oscillation limit, and this oscillation limit gain is used as a viscosity equivalent value representing viscosity of the measured fluid.

Abstract: The oscillating velocity of an oscillating body in a fluid to be measured is positively fed back, so as to activate an actuator. The oscillating state of the oscillating body is monitored while making a velocity feedback gain increase. The velocity feedback gain when the oscillating body has oscillated is obtained as an oscillation limit gain at the oscillation limit, and this oscillation limit gain is used as a viscosity equivalent value representing viscosity of the measured fluid.

Abstract: The amplitude control of a cantilever based on the van der Pol model is performed through feedback using measurement data on a deflection of the cantilever. A self-oscillating circuit integrates a deflection angle signal of a cantilever detected by a deflection angle measuring mechanism using an integrator, multiplies a resulting integral value by linear feedback gain generated by a gain generator, and an output corresponding to the linear feedback signal is generated. Also, the self-oscillating circuit cubes the deflection angle signal using analog multipliers, integrates the resulting values using integrators, multiplies the resulting integral values by a nonlinear feedback gain generated by a gain generator, and an output corresponding to the nonlinear feedback signal is generated. Furthermore, the self-oscillating circuit adds the outputs together using an adder, and a voltage signal for a piezo element is generated.

Abstract: In a tapping mode Atomic Force Microscope (AFM) system, a probe is excited at an excitation frequency other than the probe's first natural frequency to produce a response signal manifesting a grazing bifurcation between “non-collision” and “collision” states of the AFM system, so that an additional characteristic frequency component is generated in the “collision” state. The magnitude of the additional characteristic frequency component is monitored in real time, and the probe-sample separation is adjusted to maintain the monitored magnitude at an optimal value to operate the AFM system at near-grazing conditions.

Abstract: The amplitude control of a cantilever based on the van der Pol model is performed through a feedback using the measurement data on a deflection of the cantilever. A self-oscillating circuit integrates a deflection angle signal of a cantilever detected by a deflection angle measuring mechanism using an integrator, multiplies a resulting integral value by linear feedback gain Klin generated by a gain generator, and an output corresponding to the linear feedback signal is generated. Also, the self-oscillating circuit cubes the deflection angle signal using analog multipliers, integrates the resulting values using integrators, multiplies the resulting integral values by a nonlinear feedback gain Knon generated by a gain generator, and an output corresponding to the nonlinear feedback signal is generated. Furthermore, the self-oscillating circuit 40 adds the outputs together using an adder, and a voltage signal VC for a piezo element is generated.

Abstract: A cantilever control device is provided that can prevent, in an atomic force microscope, self-excited oscillation of a cantilever from stopping and prevent a probe of the cantilever from coming into contact with a measurement object. In the atomic force microscope, a cantilever control device 1 is constituted from a cantilever 10 having a probe 12, an actuator 20 that causes self-excited oscillation in the cantilever 10, an oscillation velocity detector 30 that detects the oscillation velocity of the cantilever 10, a displacement calculator 32 that calculates the oscillation displacement of the cantilever 10, and a controller 40 that generates a signal for driving the actuator 20. A feedback control signal S is represented as (K?G·x2)·dx/dt, where x is the oscillation displacement of the cantilever 10, dx/dt is the oscillation velocity of the cantilever 10, and both K and G are feedback gains of a positive value.

Abstract: In a tapping mode Atomic Force Microscope (AFM) system, a probe is excited at an excitation frequency other than the probe's first natural frequency to produce a response signal manifesting a grazing bifurcation between “non-collision” and “collision” states of the AFM system, so that an additional characteristic frequency component is generated in the “collision” state. The magnitude of the additional characteristic frequency component is monitored in real time, and the probe-sample separation is adjusted to maintain the monitored magnitude at an optimal value to operate the AFM system at near-grazing conditions.

Abstract: A cantilever control device is provided that can prevent, in an atomic force microscope, self-excited oscillation of a cantilever from stopping and prevent a probe of the cantilever from coming into contact with a measurement object. In the atomic force microscope, a cantilever control device 1 is constituted from a cantilever 10 having a probe 12, an actuator 20 that causes self-excited oscillation in the cantilever 10, an oscillation velocity detector 30 that detects the oscillation velocity of the cantilever 10, a displacement calculator 32 that calculates the oscillation displacement of the cantilever 10, and a controller 40 that generates a signal for driving the actuator 20. A feedback control signal S is represented as (K?G·x2)·dx/dt, where x is the oscillation displacement of the cantilever 10, dx/dt is the oscillation velocity of the cantilever 10, and both K and G are feedback gains of a positive value.