Abstract: The miniaturized piezoelectric accelerometer includes a support frame (102) having a cavity (104) and a seismic mass (108) supported by a plurality of suspension beams (110) extending from the support frame (102). Each of the suspension beams (110) has a piezoelectric thin film coated on a top surface thereof, with a pair of inter-digital electrodes (114) deposited on an upper surface of each piezoelectric thin film. The presence of acceleration excites bending and thus strain in the piezoelectric thin film, which in turn causes electrical signals to be generated over terminals of the electrodes (114). To collect constructively the output of the electrodes (114), one terminal of each of the electrodes (114) is routed to and electrically connected at a top surface (308) of the seismic mass (108).

Abstract: A liquid dispensing apparatus is provided which has a syringe for storing and dispensing a liquid, and a connector passage connected to the syringe. A positive pressure passage is connected to an air source for supplying positive pressure to the syringe, and there is a pressure valve located along the positive pressure passage that is operative to control the flow of air along the positive pressure passage. A vacuum passage is connected to a vacuum generator for supplying vacuum pressure to the syringe, and there is a vacuum valve located along the vacuum passage that is operative to control the flow of air along the vacuum passage. The positive pressure passage and vacuum passage are connected to the connector passage. A pressure sensor is also provided to measure the pressure in the connector passage.

Abstract: A piezoelectric sensor comprising a piezoelectric film formed on a surface of an object to be monitored; a plurality of electrodes formed on a surface of the piezoelectric film; and wherein electrical polarization of the piezoelectric film is about coplanar with the surface of the piezoelectric film. A method of forming a piezoelectric sensor. The method comprises forming a piezoelectric film on a surface of an object to be monitored; forming electrodes on a surface of the piezoelectric film; and orientating electrical polarization in the piezoelectric film to be about coplanar with the surface of the piezoelectric film.

Abstract: The miniaturized piezoelectric accelerometer includes a support frame (102) having a cavity (104) and a seismic mass (108) supported by a plurality of suspension beams (110) extending from the support frame (102). Each of the suspension beams (110) has a piezoelectric thin film coated on a top surface thereof, with a pair of inter-digital electrodes (114) deposited on an upper surface of each piezoelectric thin film. The presence of acceleration excites bending and thus strain in the piezoelectric thin film, which in turn causes electrical signals to be generated over terminals of the electrodes (114). To collect constructively the output of the electrodes (114), one terminal of each of the electrodes (114) is routed to and electrically connected at a top surface (308) of the seismic mass (108).

Abstract: A driving mechanism comprises a fixed housing, a movable housing on which an object to be driven is mounted and a driving motor which is operative to drive the movable housing to move linearly as well as to rotate relative to the fixed housing. An inductance-type encoder determines both linear and rotary displacement of the movable housing relative to the fixed housing, whereby to provide closed-loop control of the position of the object in both linear and rotary directions.

Abstract: An alignment tool for a bonding apparatus comprises a loading surface for receiving a pushing force from a surface of a device which is attached to the bonding apparatus, the loading surface being arranged and constructed to experience a tilting moment upon receiving an unequally distributed pushing force from a misaligned device acting on it. The loading surface transmits the tilting moment experienced by it to a sensing surface which is operatively connected to the loading surface through a columnar body, which has a smaller width than the loading surface and the sensing surface, and which connects the loading surface and the sensing surface. An array of piezoelectric elements communicates with the sensing surface and produces electrical signals in response to the tilting moment such that a computing unit operatively connected to the piezoelectric elements may detect a direction of tilt of the loading surface from the electrical signals produced by the piezoelectric elements.

Abstract: A method for damping vibrations in a stepper motor with micro-stepping control which comprises the steps of identifying the force amplitudes and phase shifts of multiple harmonic detent torques of the stepper motor, such as the first, second and fourth harmonic detent torques, and tuning the stepper motor with different current commands until minimum friction and resistive torque are obtained. Thereafter, a compensating harmonic current derived from said force amplitudes and phase shifts of the said multiple harmonic detent torques is injected into a current command during operation of the stepper motor to compensate for torque ripples.

Abstract: A driving mechanism comprises a fixed housing, a movable housing on which an object to be driven is mounted and a driving motor which is operative to drive the movable housing to move linearly as well as to rotate relative to the fixed housing. An inductance-type encoder determines both linear and rotary displacement of the movable housing relative to the fixed housing, whereby to provide closed-loop control of the position of the object in both linear and rotary directions.

Abstract: A liquid dispensing apparatus is provided which has a syringe for storing and dispensing a liquid, and a connector passage connected to the syringe. A positive pressure passage is connected to an air source for supplying positive pressure to the syringe, and there is a pressure valve located along the positive pressure passage that is operative to control the flow of air along the positive pressure passage. A vacuum passage is connected to a vacuum generator for supplying vacuum pressure to the syringe, and there is a vacuum valve located along the said vacuum passage that is operative to control the flow of air along the vacuum passage. The positive pressure passage and vacuum passage are connected to the connector passage. A pressure sensor is also provided to measure the pressure in the connector passage.

Abstract: An alignment tool for a bonding apparatus comprises a loading surface for receiving a pushing force from a surface of a device which is attached to the bonding apparatus, the loading surface being arranged and constructed to experience a tilting moment upon receiving an unequally distributed pushing force from a misaligned device acting on it. The loading surface transmits the tilting moment experienced by it to a sensing surface which is operatively connected to the loading surface through a columnar body, which has a smaller width than the loading surface and the sensing surface, and which connects the loading surface and the sensing surface. An array of piezoelectric elements communicates with the sensing surface and produces electrical signals in response to the tilting moment such that a computing unit operatively connected to the piezoelectric elements may detect a direction of tilt of the loading surface from the electrical signals produced by the piezoelectric elements.

Abstract: A method for damping vibrations in a stepper motor with micro-stepping control which comprises the steps of identifying the force amplitudes and phase shifts of multiple harmonic detent torques of the stepper motor, such as the first, second and fourth harmonic detent torques, and tuning the stepper motor with different current commands until minimum friction and resistive torque are obtained. Thereafter, a compensating harmonic current derived from said force amplitudes and phase shifts of the said multiple harmonic detent torques is injected into a current command during operation of the stepper motor to compensate for torque ripples.

Abstract: A linear actuator for a motion system is provided with a velocity sensor for monitoring a velocity of an actuation arm that it is driving. The linear actuator comprises a magnetic field, a first coil that is controllably movable within the magnetic field by adjusting a current flowing through the first coil whereby to drive the actuation arm and a second coil that is movable with the first coil and configured such that a voltage is inducible in the second coil that is proportional to its velocity. A controller device is connected to the second coil for receiving feedback indicating the voltage induced in the second coil whereby a velocity of the actuation arm is determinable, wherein the controller device is further connected to the first coil and is operative to adjust the current flowing in the first coil based upon said feedback for controllably driving the actuation arm.

Abstract: Apparatus for detecting the oscillation amplitude of an oscillating object (3) includes an optical radiation source (9) and a detector (10) including first and second optical radiation sensing areas (24A, 24B) adjacent each other. The detector (10) and the optical radiation source (9) are adapted to be located opposite each other with the oscillating object (3) located between the source (9) and the detector (10) so that the object (3) blocks a portion of the sensing areas (24A, 24B) from receiving optical radiation from the source (9). A processor (18) coupled to the detector (10) receives first and second output signals representing the magnitude of optical radiation sensed by the first and second optical radiation sensing areas (24A, 24B), respectively. The processor (18) processes the first and second output signals to obtain an indication of the amplitude of oscillation of the object (3).