Patents Assigned to Specs Zürich GmbH
  • Patent number: 8950010
    Abstract: The piezoelectric response of a sample (3) is measured by applying a scanning probe microscope, whose probe (2) is in contact with the sample (3). The probe is mounted to a cantilever (1) and an actuator (5) is driven by a feedback loop (7, 11, 12, 4) to oscillate at a resonance frequency f. An AC voltage with principally the same frequency f but with a phase (with respect to the oscillation) and/or amplitude varying periodically with a frequency fmod is applied to the probe for generating a piezoelectric response of the sample (3). A lock-in detector (20) measures the spectral components at the frequency fmod of the control signals (K, f) of the feedback loop. These components describe the piezoelectric response and can be recorded as output signals of the device. The method allows a reliable operation of the detector oscillator resonator (1) at its resonance frequency and provides a high sensitivity.
    Type: Grant
    Filed: August 27, 2008
    Date of Patent: February 3, 2015
    Assignee: Specs Zürich GmbH
    Inventor: Jörg Rychen
  • Patent number: 8347411
    Abstract: The scanning probe microscope has a primary control loop (7, 11, 12) for keeping the phase and/or amplitude of deflection at constant values as well as a secondary control loop (9) that e.g. keeps the frequency of the cantilever oscillation constant by applying a suitable DC voltage to the probe while, at the same time, a conservative AC excitation is applied thereto. By actively controlling the frequency with the first control loop (7, 11, 12) and subsequently controlling the DC voltage in order to keep the frequency constant, a fast system is created that allows to determine the contact potential difference or a related property of the sample (3) quickly.
    Type: Grant
    Filed: July 14, 2006
    Date of Patent: January 1, 2013
    Assignee: Specs Zürich GmbH
    Inventors: Dominik Ziegler, Andreas Christian Stemmer, Jorg Rychen
  • Patent number: 8296857
    Abstract: The piezo-electric actuator (1) to oscillate the probe of a scanning probe microscope is arranged in the feedback branch (3) of an analog amplifier (4). A current source (10) is provided for feeding a defined alternating current to the input of the amplifier (4). The amplifier (4) strives to adjust the voltage over the actuator (1) such that the current from the current source (10) flows through the actuator (1). As the current through the actuator (1) is proportional to its deflection, this design allows to run the actuator at constant amplitude without the need of complex feedback loops.
    Type: Grant
    Filed: December 17, 2008
    Date of Patent: October 23, 2012
    Assignee: Specs Zürich GmbH
    Inventor: Jörg Rychen
  • Patent number: 8245316
    Abstract: The scanning probe microscope applies a sum of an AC voltage (Uac) and a DC voltage (Udc) to its probe. The frequency of the AC voltage (Uac) substantially corresponds to the mechanical oscillation frequency of the probe, but its phase in respect to the mechanical oscillation varies periodically. The phase modulation has a frequency fmod. The microscope measures the frequency (f) or the amplitude (K) of a master signal (S) applied to the probe's actuator, or it measures the phase of the mechanical oscillation of the cantilever in respect to the master signal (S). The spectral component at frequency fmod of the measured signal is fed to a feedback loop controller, which strives to keep it zero by adjusting the DC voltage (Udc), thereby keeping the DC voltage at the contact voltage potential.
    Type: Grant
    Filed: December 15, 2006
    Date of Patent: August 14, 2012
    Assignee: Specs Zürich GmbH
    Inventor: Jörg Rychen
  • Publication number: 20100031404
    Abstract: The scanning probe microscope applies a sum of an AC voltage (Uac) and a DC voltage (Udc) to its probe. The frequency of the AC voltage (Uac) substantially corresponds to the mechanical oscillation frequency of the probe, but its phase in respect to the mechanical oscillation varies periodically. The phase modulation has a frequency fmod. The microscope measures the frequency (f) or the amplitude (K) of a master signal (S) applied to the probe's actuator, or it measures the phase of the mechanical oscillation of the cantilever in respect to the master signal (S). The spectral component at frequency fmod of the measured signal is fed to a feedback loop controller, which strives to keep it zero by adjusting the DC voltage (Udc), thereby keeping the DC voltage at the contact voltage potential.
    Type: Application
    Filed: December 15, 2006
    Publication date: February 4, 2010
    Applicant: Specs Zuerich GmbH
    Inventor: Jörg Rychen