A scanning probe microscope includes a cantilever having a probe at a free end thereof; a scanner to three-dimensionally relatively move the probe and a sample; a vibrator to vibrate the cantilever based on a vibrating signal; a displacement detector to detect a displacement of the cantilever and to output a displacement signal indicating the displacement; and a phase difference information detecting section to generate a phase signal including information of a phase difference between the vibrating signal and the displacement signal. The phase difference information detecting section includes a phase regulating portion to provide, to the phase difference, a phase offset to cancel an initial phase difference present in a state in which the probe is not in contact with the sample.

A scanning probe microscope includes a cantilever having a probe at a free end thereof; a scanner to three-dimensionally relatively move the probe and a sample; a vibrator to vibrate the cantilever based on a vibrating signal; a displacement detector to detect a displacement of the cantilever and to output a displacement signal indicating the displacement; and a phase difference information detecting section to generate a phase signal including information of a phase difference between the vibrating signal and the displacement signal. The phase difference information detecting section includes a phase regulating portion to provide, to the phase difference, a phase offset to cancel an initial phase difference present in a state in which the probe is not in contact with the sample.

Harmonic feedback atomic force microscopy (HF-AFM) includes regulating feedback in oscillating probe atomic force microscopy (AFM) based upon an extracted frequency component of a probe response signal. Feedback in conventional oscillating probe AFM uses the probe response signal as a whole (or at least a driven frequency component of the probe response signal). The extracted frequency of the extracted frequency component of HF-AFM generally is different from any substantially driven frequency that generates the probe oscillation and may be a harmonic of a driven frequency. The regulating may include responding to the strength or weakness of the extracted frequency component such that weakening (or strengthening) of the extracted frequency component contributes positively to a decrease (or an increase) in the average tip-sample distance and contributes negatively to an increase (or a decrease) in the average tip-sample distance.

A control methodology for scanning tunneling microscopy is disclosed. Instead of utilizing Integral-based control systems, the methodology utilizes a dual-control algorithm to direct relative advancement of a STM tip towards a sample. A piezo actuator and stepper motor advances an STM tip towards a sample at a given distance until measuring a current greater than or equal to a desired setpoint current. Readings of the contemporaneous step are analyzed to direct the system to change continue or change direction and also determine the size of each step. In simulations where Proportion and/or Integral control methodology was added to the algorithm the stability of the feedback control is decreased. The present methodology accounts for temperature variances in the environment and also appears to clean and protect the tip electrode, prolonging its useful life.

A control methodology for scanning tunneling microscopy is disclosed. Instead of utilizing Integral-based control systems, the methodology utilizes a dual-control algorithm to direct relative advancement of a STM tip towards a sample. A piezo actuator and stepper motor advances an STM tip towards a sample at a given distance until measuring a current greater than or equal to a desired setpoint current. Readings of the contemporaneous step are analyzed to direct the system to change continue or change direction and also determine the size of each step. In simulations where Proportion and/or Integral control methodology was added to the algorithm the stability of the feedback control is decreased. The present methodology accounts for temperature variances in the environment and also appears to clean and protect the tip electrode, prolonging its useful life.

A wet cell apparatus is provided and includes a sensor body defining a nano-pore by which respective cell interiors are fluidly communicative and a scanning probe microscope (SPM) tip. The SPM tip is configured to draw a molecule through the nano-pore from one of the respective cell interiors whereby sensing components of the sensor body identify molecule components as the molecule passes through the nano-pore.

Systems and methods configured for simultaneous imaging and stimulation using a microscope system. The microscope system can have a relatively small size compared to an average microscope system. The microscope can comprise in part an imaging light source and a stimulation light source. Light from the imaging light source and the stimulation light source can be spectrally separated to reduce cross talk between the stimulation light and the imaging light.

The imaging mode presented here combines the features and benefits of amplitude modulated (AM) atomic force microscopy (AFM), sometimes called AC mode AFM, with frequency modulated (FM) AFM. In AM-FM imaging, the topographic feedback from the first resonant drive frequency operates in AM mode while the second resonant drive frequency operates in FM mode and is adjusted to keep the phase at 90 degrees, on resonance. With this approach, frequency feedback on the second resonant mode and topographic feedback on the first are decoupled, allowing much more stable, robust operation.

The imaging mode presented here combines the features and benefits of amplitude modulated (AM) atomic force microscopy (AFM), sometimes called AC mode AFM, with frequency modulated (FM) AFM. In AM-FM imaging, the topographic feedback from the first resonant drive frequency operates in AM mode while the second resonant drive frequency operates in FM mode and is adjusted to keep the phase at 90 degrees, on resonance. With this approach, frequency feedback on the second resonant mode and topographic feedback on the first are decoupled, allowing much more stable, robust operation.

A controller for cantilever-based instruments, including atomic force microscopes, molecular force probe instruments, high-resolution profilometers and chemical or biological sensing probes. The controller samples the output of the photo-detector commonly used to detect cantilever deflection in these instruments with a very fast analog/digital converter (ADC). The resulting digitized representation of the output signal is then processed with field programmable gate arrays and digital signal processors without making use of analog electronics. Analog signal processing is inherently noisy while digital calculations are inherently perfect in that they do not add any random noise to the measured signal. Processing by field programmable gate arrays and digital signal processors maximizes the flexibility of the controller because it can be varied through programming means, without modification of the controller hardware.