30 results about "Cantilever deflection" patented technology

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.

The present methods and apparatus concern the detection and / or identification of target analytes using probe molecules. In various embodiments of the invention, the probes or analytes are attached to one or more cantilevers. Binding of a probe to an analyte results in deflection of the cantilever, detected by a detection unit. A counterbalancing force may be applied to restore the cantilever to its original position. The counterbalancing force may be magnetic, electrical or radiative. The detection unit and the mechanism generating the counterbalancing force may be operably coupled to an information processing and control unit, such as a computer. The computer may regulate a feedback loop that maintains the cantilever in a fixed position by balancing the deflecting force and the counterbalancing force. The concentration of analytes in a sample may be determined from the magnitude of the counterbalancing force required to maintain the cantilever in a fixed position.

The present methods and apparatus concern the detection and / or identification of target analytes using probe molecules. In various embodiments of the invention, the probes or analytes are attached to one or more cantilevers. Binding of a probe to an analyte results in deflection of the cantilever, detected by a detection unit. A counterbalancing force may be applied to restore the cantilever to its original position. The counterbalancing force may be magnetic, electrical or radiative. The detection unit and the mechanism generating the counterbalancing force may be operably coupled to an information processing and control unit, such as a computer. The computer may regulate a feedback loop that maintains the cantilever in a fixed position by balancing the deflecting force and the counterbalancing force. The concentration of analytes in a sample may be determined from the magnitude of the counterbalancing force required to maintain the cantilever in a fixed position.

A method for measuring nm-scale tip-sample capacitance comprising: (a) measuring a cantilever deflection and a change in probe-sample capacitance relative to a reference level as a function of a probe assembly height; (b) fitting out-of-contact data to a function; (c) subtracting the function from capacitance data to get a residual capacitance as a function of the probe assembly height; and (d) determining the residual capacitance at a z-position where the cantilever deflection is zero.

A phase feedback AFM (atomic force microscope) and method for the phase feedback AFM. A cantilever is driven to oscillate at a constant frequency close to the resonance frequency of the cantilever by a driving signal. The distance between the probe and the sample is controlled such that the phase difference between the driving signal and a cantilever deflection signal indicating deflections of the cantilever is kept constant. The phase feedback AFM has an amplifier-controller for receiving the cantilever deflection signal, the output from an oscillator for driving the cantilever into oscillation, and a signal representing a reference amplitude of oscillation of the cantilever. The phase feedback AFM further includes a feedback circuit which receives the output from the amplifier-controller which controls the cantilever deflection signal to a preset amplitude.

An approach to detect when a cantilever loses interaction with a sample, thereby detecting when a portion of an image obtained using a cantilever is spurious is presented. An observer based estimation of cantilever deflection is compared to the cantilever deflection and the resulting innovation is used to detect when the cantilever loses interaction. The loss of interaction is determined when the innovation is outside of and / or below a threshold level.

The present invention is a method and system for erecting a steel truss beam assisted by a cable-stayed full cantilever. The method uses a sling tower combined with a steel structure central tower column and a cable-stayed cable; The tower crane on the top of the end of the truss girder; after the anchor boxes of the front and rear cable stays are connected with the lug plates of the steel girder joints, the tower is directly lifted to apply the pretension of the cable stays; Cantilever erection. After the hole steel girder is erected, use the method of raising the temporary support of the front pier and lifting equipment between the upper and lower supports of the sling tower to complete the cable force unloading of the stay cables. The system includes tower auxiliary truss, tower center column, upper and lower support bases, front and rear stay cables, stay cable upper and lower anchor boxes, tower top anchor beams and running mechanism. Advantages: For large-span continuous steel truss girders, a special equipment is used to assist the erection of multi-span steel truss girders, which can reduce the internal force of steel truss girder member installation, reduce the deflection of the front outrigger end, and increase the roll stability of the outrigger steel truss girder sex. And the investment is small, the cycle is short; the operation is very convenient.

A method for detecting a platelet-derived growth factor with the concentration of 0.5-10[mu]g / mL is realized by constructing a carbon nanotube micro-cantilever biosensor. The biosensor comprises a support, a substrate material, a carbon nanotube and a pick-up circuit, and the carbon nanotube is modified with a layer of nucleic acid aptamers through a phi-phi superposing effect. The method comprises the following steps: a detection probe containing a PDGF nucleic acid aptamer is made on a carbon nanotube micro-cantilever, the detection probe is put in a sample to be detected during detection, and PDGF in the sample to be detected and the nucleic acid aptamer on the detection probe form a compound and are attached to the micro-cantilever through a specific reaction; and a micro-cantilever deflection displacement or resonant frequency change caused by the mass change of the compound on the micro-cantilever is positively related to the concentration of PDGF in the sample to be detected in order to realize PDGF detection.

A method for detecting human immune globulin E with the concentration of 0.5-10[mu]g / mL is realized by constructing a carbon nanotube micro-cantilever biosensor. The biosensor comprises a support, a substrate material, a carbon nanotube and a pick-up circuit, and the carbon nanotube is modified with a layer of nucleic acid aptamers through a hydrophobic effect. The method comprises the following steps: a detection probe containing an hIgE nucleic acid aptamer is made on a carbon nanotube micro-cantilever, the detection probe is put in a sample to be detected during detection, hIgE in the sample to be detected and the nucleic acid aptamer on the detection probe form a compound and are attached to the micro-cantilever through a specific reaction; and a micro-cantilever deflection displacement or resonant frequency change caused by the mass change of the compound on the micro-cantilever is positively related to the concentration of hIgE in the sample to be detected in order to realize hIgE detection.

An atomic force microscope is described having a cantilever comprising a base and a probe tip on an end opposite the base; a cantilever drive device connected to the base; a magnetic material coupled to the probe tip, such that when an incrementally increasing magnetic field is applied to the magnetic material an incrementally increasing force will be applied to the probe tip; a moveable specimen base; and a controller constructed to obtain a profile height of a specimen at a point based upon a contact between the probe tip and a specimen, and measure an adhesion force between the probe tip and the specimen by, under control of a program, incrementally increasing an amount of a magnetic field until a release force, sufficient to break the contact, is applied. An imaging method for atomic force microscopy involving measuring a specimen profile height and adhesion force at multiple points within an area and concurrently displaying the profile and adhesion force for each of the points is also described. A microscope controller is also described and is constructed to, for a group of points, calculate a specimen height at a point based upon a cantilever deflection, a cantilever base position and a specimen piezo position; calculate an adhesion force between a probe tip and a specimen at the point by causing an incrementally increasing force to be applied to the probe tip until the probe tip separates from a specimen; and move the probe tip to a new point in the group.

The present methods and apparatus concern the detection and / or identification of target analytes using probe molecules. In various embodiments of the invention, the probes or analytes are attached to one or more cantilevers. Binding of a probe to an analyte results in deflection of the cantilever, detected by a detection unit. A counterbalancing force may be applied to restore the cantilever to its original position. The counterbalancing force may be magnetic, electrical or radiative. The detection unit and the mechanism generating the counterbalancing force may be operably coupled to an information processing and control unit, such as a computer. The computer may regulate a feedback loop that maintains the cantilever in a fixed position by balancing the deflecting force and the counterbalancing force. The concentration of analytes in a sample may be determined from the magnitude of the counterbalancing force required to maintain the cantilever in a fixed position.

A high precision micro / nanoscale machining system. A multi-axis movement machine provides relative movement along multiple axes between a workpiece and a tool holder. A cutting tool is disposed on a flexible cantilever held by the tool holder, the tool holder being movable to provide at least two of the axes to set the angle and distance of the cutting tool relative to the workpiece. A feedback control system uses measurement of deflection of the cantilever during cutting to maintain a desired cantilever deflection and hence a desired load on the cutting tool.

The embodiment of the invention discloses a method for measuring the elastic modulus of banknotes, which is used to solve the technical problem that the stretching method is not suitable for measuring the elastic modulus of old banknotes. The method of the embodiment of the present invention includes: measuring the deflection of the cantilever beam at both ends of the banknote; fitting the relationship formula between the elastic modulus and the bending deflection of the banknote through a data fitting method; substituting the deflection of the cantilever beam into the relationship as the bending deflection formula to calculate the elastic modulus of the banknote. The embodiment of the present invention also provides a device for measuring the maximum bending deflection of banknotes. The embodiments of the present invention can solve the technical problem that the stretching method is not suitable for measuring the elastic modulus of old banknotes.

Atomic Force Microscopes (AFMs) allow forces within systems under observation to be probed from the piconewton forces of a single covalent bond to the forces exerted by cells in the micronewton range. The pendulum geometry prevents the snap-to-contact problem afflicting soft cantilevers in AFMs which enable attonewton force sensitivity. However, the microscopic length scale studies of cellular / subcellular forces parallel to the imaging plane of an optical microscope requires high sensitivity force measurements at high sampling frequencies despite the difficulties of implementing the pendulum geometry from constraints imposed by the focused incoming / outgoing light interfering with the sample surface. Additionally measurement systems for biological tissue samples in vitro must satisfy complex physical constraints to provide access to the vertical cantilever. Embodiments of the invention address these geometrical restrictions by exploiting optical periscope approaches that further allows multiple probes to be deployed and multiple optical beams within each probe.

The invention discloses a cantilever fulcrum jumping detecting tool and method. The detecting tool is clamped onto a turbine case and is used for detecting a jumping value and a tip clearance of a low-voltage turbine rotor at a cantilever end of an air compressor; the low-voltage turbine rotor is fixed by a measuring bridge; by a clearance formed in the measuring bridge and an external detecting device, the jumping value and the tip clearance of the low-voltage turbine rotor are detected; and during assembling of an engine, cantilever deflection at the position of a low-voltage turbine can beavoided by adding auxiliary supporting points on the low-voltage turbine rotor, and therefore, measured data are accurate. In addition, the failure of examination after mounting of a mounted interstage guiding device is avoided, the low-voltage turbine rotor is fixed effectively, and the problem that detection is inaccurate due to the fact that a supporting point of the low-voltage turbine rotor deflects is solved.

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.