Abstract: A linear variable transformer (LVDT) for use in a transducer. The LVDT has a non-ferromagnetic core which may eliminate Barkhausen noise and thereby improve the sensitivity of the resulting measurements. In one aspect, this system may be used in an atomic force microscope.

Abstract: An apparatus and method for measuring optically the position or angle of a variety of objects or arrays of objects, including cantilevers in scanning probe microscopy, micromechanical biological and chemical sensors and the sample or a probe in surface profilometry. The invention involves the use of one or more diffractive optical elements, including diffraction gratings and holograms, combined with conventional optical elements, to form a plurality of light beams, each with a selectable shape and intensity, from a single light source, reflect the beams off mechanical objects and process the reflected beams, all to the end of measuring the position of such objects with a high degree of precision. The invention may also be used to effect mechanical changes in such objects.

Abstract: A linear variable transformer (LVDT) for use in a transducer. The LVDT has a non-ferromagnetic core which may eliminate Barkhausen noise and thereby improve the sensitivity of the resulting measurements. In one aspect, this system may be used in an atomic force microscope.

Abstract: An apparatus and method for measuring optically the position or angle of a variety of objects or arrays of objects, including cantilevers in scanning probe microscopy, micromechanical biological and chemical sensors and the sample or a probe in surface profilometry. The invention involves the use of one or more diffractive optical elements, including diffraction gratings and holograms, combined with conventional optical elements, to form a plurality of light beams, each with a selectable shape and intensity, from a single light source, reflect the beams off mechanical objects and process the reflected beams, all to the end of measuring the position of such objects with a high degree of precision. The invention may also be used to effect mechanical changes in such objects.

Abstract: a digital system for controlling the quality factor in a resonant device. The resonant device can be any mechanically driven resonant device, but more particularly can be a device that includes a cantilever within its system, such as an atomic force microscope. The quality factor can be digitally controlled to avoid noise effect in the analog components. One of the controls can use a direct digital synthesizer implemented in a way that provides access to the output of the phase accumulator. That output is a number which usually drives eight lookup table to produce a cosine or sign output wave. The output wave is created, but the number is also adjusted to form a second number of the drives a second lookup table to create an adjustment factor. The adjustment factor is used to adjusts the output from the cosine table, to create an adjusted digital signal. The adjusted digital signal than drives a DA converter which produces an output drive for the cantilever.

Abstract: An apparatus and method for measuring optically the position or angle of a variety of objects or arrays of objects, including cantilevers in scanning probe microscopy, micromechanical biological and chemical sensors and the sample or a probe in surface profilometry. The invention involves the use of one or more diffractive optical elements, including diffraction gratings and holograms, combined with conventional optical elements, to form a plurality of light beams, each with a selectable shape and intensity, from a single light source, reflect the beams off mechanical objects and process the reflected beams, all to the end of measuring the position of such objects with a high degree of precision. The invention may also be used to effect mechanical changes in such objects.

Abstract: 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.

Abstract: A transducer that reduces noise, increases sensitivity, and improves the time response of a linear variable differential transformer (LVDT). The device replaces the primary coil and the high permeability ferromagnetic core of conventional LVDTs with a primary wound around a moving non-ferromagnetic core. In addition to reducing or eliminating Barkhausen noise, this approach reduced or eliminated a number of other undesirable effects in conventional LVDTs including excessive eddy current heating in the core, non-linearities associated with high permeability materials and the length scale of the flux circuit. These improvements are coupled with improved LVDT signal conditioning circuitry. The device is also an actuator and may be used to convert differential voltages into force.

Abstract: Techniques for coupling with devices that convert displacements into differential voltages and improve the sensitivity of such devices. The disclosed system improves the accuracy and resolution of a transducers such as an LVDT by converting certain parts of the circuit to a digital circuit. One embodiment uses a processor, although other digital processing circuitry may also be used.

Abstract: An apparatus for simulating a tactile interface with the relative position of the probe of a cantilever-based force measurement instrument, such as an atomic force microscope, molecular force probe or profilometer, or the force between the probe and a sample. The device can be easily incorporated into existing control electronics for such instruments or can be incorporated into a relatively small and simple hand-held device to be used with such instruments.

Abstract: An apparatus and method for measuring optically the position or angle of a variety of objects or arrays of objects, including cantilevers in scanning probe microscopy, micromechanical biological and chemical sensors and the sample or a probe in surface profilometry. The invention involves the use of one or more diffractive optical elements, including diffraction gratings and holograms, combined with conventional optical elements, to form a plurality of light beams, each with a selectable shape and intensity, from a single light source, reflect the beams off mechanical objects and process the reflected beams, all to the end of measuring the position of such objects with a high degree of precision. The invention may also be used to effect mechanical changes in such objects.

Abstract: A transducer that reduces noise, increases sensitivity, and improves the time response of a linear variable differential transformer (LVDT). The device replaces the primary coil and the high permeability ferromagnetic core of conventional LVDTs with a primary wound around a moving non-ferromagnetic core. In addition to reducing or eliminating Barkhausen noise, this approach reduced or eliminated a number of other undesirable effects in conventional LVDTs including excessive eddy current heating in the core, non-linearities associated with high permeability materials and the length scale of the flux circuit. These improvements are coupled with improved LVDT signal conditioning circuitry. The device is also an actuator and may be used to convert differential voltages into force.