摘要:
A method to compensate for stress deflection in a compound microprobe that includes a substrate, a microcantilever extending outwardly from the substrate, and a film formed on the microcantilever. The method preferably comprises the steps of determining an amount of stress-induced deflection of the microcantilever, and then mounting the microprobe so as to compensate for the stress-induced deflection. The mounting step preferably includes selecting a compensation piece based upon the amount of stress-induced deflection, where the compensation piece is a wedge generally aligning the microcantilever with a deflection detection apparatus. In general, the step of selecting the compensation piece includes correcting an angle between a longitudinal axis of the microcantilever and the substrate so as to insure that light reflected from the microcantilever during operation contacts a detector of a deflection detection apparatus. The preferred embodiment is also directed to a microprobe assembly having a microcantilever and a substrate coupled to a support that includes a compensation piece disposed intermediate the support and the substrate. Again, the compensation piece is configured to compensate for an amount of static deflection of the microcantilever.
摘要:
An AFM that combines an AFM Z position actuator and a self-actuated Z position cantilever (both operable in cyclical mode and contact mode), with appropriate nested feedback control circuitry to achieve high-speed imaging and accurate Z position measurements. A preferred embodiment of an AFM for analyzing a surface of a sample in either ambient air or fluid includes a self-actuated cantilever having a Z-positioning element integrated therewith and an oscillator that oscillates the self-actuated cantilever at a frequency generally equal to a resonant frequency of the self-actuated cantilever and at an oscillation amplitude generally equal to a setpoint value. The AFM includes a first feedback circuit nested within a second feedback circuit, wherein the first feedback circuit generates a cantilever control signal in response to vertical displacement of the self-actuated cantilever during a scanning operation, and the second feedback circuit is responsive to the cantilever control signal to generate a position control signal. A Z position actuator is also included within the second feedback circuit and is responsive to the position control signal to position the sample. In operation, preferably, the cantilever control signal alone is indicative of the topography of the sample surface. In a further embodiment, the first feedback circuit includes an active damping circuit for modifying the quality factor (“Q”) of the cantilever resonance to optimize the bandwidth of the cantilever response.
摘要:
Thermal drift and acoustic vibrations in the AFM are reduced using a probe-based detection device that references the topography measurement of the AFM to the sample surface in the proximity of the measurement probe. A differential measurement is made between the reference probe and the measurement probe for high sensitivity roughness quantification and defect detection. Multi-probe arrays may be used for large area defect detection with immunity from thermal and acoustic noise sources.
摘要:
An AFM that combines an AFM Z position actuator and a self-actuated Z position cantilever (both operable in cyclical mode and contact mode), with appropriate nested feedback control circuitry to achieve high-speed imaging and accurate Z position measurements. A preferred embodiment of an AFM for analyzing a surface of a sample includes a self-actuated cantilever having a Z-positioning element integrated therewith and an oscillator that oscillates the self-actuated cantilever at a frequency generally equal to a resonant frequency of the self-actuated cantilever and at an oscillation amplitude generally equal to a setpoint value. The AFM includes a first feedback circuit nested within a second feedback circuit, wherein the first feedback circuit generates a cantilever control signal in response to vertical displacement of the self-actuated cantilever during a scanning operation, and the second feedback circuit is responsive to the cantilever control signal to generate a position control signal. A Z position actuator is also included within the second feedback circuit and is responsive to the position control signal to position the sample. In operation, preferably, the cantilever control signal alone is indicative of the topography of the sample surface. In a further embodiment, the first feedback circuit includes an active damping circuit for modifying the quality factor (“Q”) of the cantilever resonance to optimize the bandwidth of the cantilever response.
摘要:
According to a first aspect of the preferred embodiment, a three-axis sensor assembly for use in an elastomeric material includes a first pair of sensors disposed along a first pair of respective axes that intersect, the first sensors being adapted to detect a force in a first direction. In addition, the sensor assembly includes a second pair of sensors disposed along a second pair of respective axes that intersect, the second sensors detecting a force in a second direction generally orthogonal to the first direction. Furthermore, in the assembly, the force measured in the first direction is equal to the difference between the outputs of the first sensors, and the force measured in the second direction is equal to the difference between the outputs of said second sensors. According to another aspect of the preferred embodiment, the sum of the outputs of the first sensors and the second sensors equals a force in a third direction orthogonal to the first and second directions. In another aspect of the preferred embodiment, the first pair of sensors are disposed on first opposed faces of a pyramid-shaped body, and the second pair of sensors are disposed on second opposed faces of the pyramid-shaped body. In addition, the elastomeric material can be a vehicle tire, and the tire may include a plurality of the sensor assemblies disposed about its perimeter in mutually spaced relationship.
摘要:
A scanning probe microscope method and apparatus that modifies imaging dynamics using an active drive technique to optimize the bandwidth of amplitude detection. The deflection is preferably measured by an optical detection system including a laser and a photodetector, which measures cantilever deflection by an optical beam bounce technique or another conventional technique. The detected deflection of the cantilever is subsequently demodulated to give a signal proportional to the amplitude of oscillation of the cantilever, which is thereafter used to drive the cantilever.
摘要:
Thermal drift and acoustic vibrations in the AFM are reduced using a probe-based detection device that references the topography measurement of the AFM to the sample surface in the proximity of the measurement probe. A differential measurement is made between the reference probe and the measurement probe for high sensitivity roughness quantification and defect detection. Multi-probe arrays may be used for large area defect detection with immunity from thermal and acoustic noise sources.
摘要:
A tire sensor assembly that is embedded in an elastomeric tire at a particular radial depth inwardly from a contact patch of the tire includes a flexible generally pyramid-shaped body and a pair of first strain sensors disposed on first opposed faces of the pyramid-shaped body, the first strain sensors detecting a force in a first direction. In addition, the assembly includes a pair of second strain sensors disposed on second opposed faces of the pyramid-shaped body, the second strain sensors detecting a force in a second direction. Moreover, each face of the first and second opposed faces is non-planar. Preferably, the first and second opposed faces of the pyramid-shaped body are curved and generally symmetrical about an axis extending longitudinally through the apex of the body so as to allow adjustment of the sensitivity of the sensor assembly generally independent of the radial depth. In one example, the first and second opposed faces are concave such that the sensor assembly is more sensitive to a tensile strain and less sensitive to a shear strain.
摘要:
A scanning probe microscope method and apparatus that modifies imaging dynamics using an active drive technique to optimize the bandwidth of amplitude detection. The deflection is preferably measured by an optical detection system including a laser and a photodetector, which measures cantilever deflection by an optical beam bounce technique or another conventional technique. The detected deflection of the cantilever is subsequently demodulated to give a signal proportional to the amplitude of oscillation of the cantilever, which is thereafter used to drive the cantilever.
摘要:
A scanning probe microscope method and apparatus that modifies imaging dynamics using an active drive technique to optimize the bandwidth of amplitude detection. The deflection is preferably measured by an optical detection system including a laser and a photodetector, which measures cantilever deflection by an optical beam bounce technique or another conventional technique. The detected deflection of the cantilever is subsequently demodulated to give a signal proportional to the amplitude of oscillation of the cantilever, which is thereafter used to drive the cantilever.