Abstract: A driving apparatus includes a piezoelectric element which undergoes expansion/contraction motion by a driving signal; a driving shaft which is mounted on the piezoelectric element, and undergoes reciprocating movement according to the expansion/contraction motion of the piezoelectric element; a first movement member which is friction-engaged with the driving shaft, and moves due to the reciprocating movement of the driving shaft; and a first control portion which applies driving signals to the piezoelectric element; the first control portion applies driving control pulse signals when the first movement member is to be moved, and applies stop control pulse signals when the stopped first movement member is not to be moved to put the first movement member into a vibration-arrested state. By this means, the stopped first movement member can be smoothly moved, and the first movement member in motion can be smoothly stopped.

Abstract: In a method for calibration, a piezo-actuator (1) is actuated in a motor vehicle by a control circuit and an output stage. The piezo actuator is, in particular, part of the injection valve. The piezo-actuator (1) is subjected to an electric calibration pulse that is in the high-level signal range thereof when the control circuit and the output stage are in operation, the frequency thereof being modified over time. The associated electric impendence curve over the frequency is determined and evaluated during the calibration pulse. The output stage is controlled by the control circuit in such a manner that the calibration pulse is generated.

Abstract: Operating method of a piezolinear drive having a group of piezo stack actuators which drive a rotor, in which the actuators constitute a multilayer ceramic arrangement situated on a common substrate, wherein a first stack part within the stack of the multilayer arrangement is formed as a longitudinal actuator, and a second stack part as a shearing actuator, and the latter being at least indirectly in clamping and shearing contact with the rotor, and at least two identical actuators being situated next to each other in order to perform alternate clamping and advancing movements in the step operation for a rough positioning operation in the step mode, wherein the adjacent actuators of the group are controlled to perform alternate clamping and advancing movements, with control signals being derived from a speed-proportional control variable.

Abstract: Devices and methods are provided for boosting a battery voltage and driving an actuator with programmable voltage shapes. In one embodiment, there is provided a device (e.g., an actuator driver) that includes: a boost circuit coupled to the actuator and a battery; a switch driver coupled to the boost circuit; at least one current source coupled to the actuator; a switch-driver amplifier coupled to the switch driver and the at least one current source; and a microcontroller or an application specific integrated circuit (ASIC) coupled to and controlling the at least one current source to apply a shaped voltage to the actuator.

Abstract: In a piezoelectric actuator (8) comprising a layered piezoelectric element (14) which consists of alternately stacked expansion and contraction layers (14a) and electrode layers (14b), a driving shaft (15) of which one end is fixed to one end of the piezoelectric element (14) in expansion and contraction direction, a movable member (15) frictionally engaging with the driving shaft (15) and a collar (17) bonded to the circumference of the piezoelectric element (14), by bonding the collar (17) to the circumference of the plurality of the expansion and contraction layers (14a) with an adhesive (G) so that fastening force of the collar (17) to the expansion and contraction layers (14a) is imbalanced with reference to the center of the cross section of the piezoelectric element (14) so that the piezoelectric element (14) expands and contracts in an imbalanced manner to incline the driving shaft (15) to displace minutely the movable member (16).

Abstract: A method of driving electromechanical devices such as interferometric modulators includes applying a voltage along a common line to release the electromechanical devices along the common line, followed by applying an address voltage along the common line to actuate selected electromechanical devices along the common line based on voltages applied along segment lines. Hold voltages may be applied along common lines between applications of release and address voltages, and the segment voltages may be selected to be sufficiently small that the segment voltages will not affect the state of the electromechanical devices along other common lines not being written to.

Abstract: A system and method for biasing a capacitive ultrasonic transducer (CMUT) device with a circuit that includes a CMUT that includes a first plate and a second plate that form a membrane structure; a circuit voltage source at a complementary metal-oxide-semiconductor (CMOS) compatible voltage; a bias voltage source that applies a bias voltage greater than a CMOS compatible voltage and is applied to the first plate; and readout electronics with an input connected on the second plate side of the circuit.

Abstract: A method includes an electrostatic capacitance detecting step of detecting electrostatic capacitances of opposing parts of a moving body side electrode and an oscillating plate electrode; an electrostatic capacitance storing step of storing the electrostatic capacitances at the first movement limit position and the second movement limit position detected at the electrostatic capacitance detecting step; a ratio calculating step of calculating a ratio of the electrostatic capacitances at the first movement limit position and the second movement limit position stored at the electrostatic capacitance storing step to a movement limit distance that is a distance between the first movement limit position and the second movement limit position; and an absolute position calculating step of calculating an absolute position of the moving body between the first movement limit position and the second movement limit position from the ratio.

Abstract: A flywheel system has an approximately toroidal flywheel rotor having an outer radius, the flywheel rotor positioned around and bound to a hub by stringers, the stringers each of a radius slightly smaller than the outer radius of the flywheel rotor. The hub is suspended from a motor-generator by a flexible shaft or rigid shaft with flexible joint, the flywheel rotor having a mass, substantially all of the mass of the flywheel rotor comprising fibers, the fibers in large part movable relative to each other. The motor-generator is suspended from a damped gimbal, and the flywheel rotor and motor-generator are within a chamber evacuatable to vacuum. An electrostatic motor/generator can also be within the same vacuum as the flywheel.

Abstract: A drive element is provided having a substrate, a seismic mass, a drive electrode and a counter-electrode, one of the two electrodes being connected to the substrate and the other of the two electrodes being connected to the seismic mass; and the drive electrode and the counter-electrodes being provided for the excitation of motion of the seismic mass in a main direction of motion; and in addition, the drive electrode includes a first and a second partial electrode, which are switchable separately from each other.

Abstract: A drive unit includes an ultrasonic actuator, which has an actuator body formed using a piezoelectric element and outputs a driving force by vibration of the actuator body, and a control section which induces vibration in the actuator body by supplying a plurality of AC voltages to the piezoelectric element. The control section provides, in combination, phase control, which controls the driving force by adjusting a phase difference between a first and a second AC voltages, and wave-number control, which controls the driving force by adjusting the wave number included in a predetermined burst period in each AC voltage.

Abstract: A method of driving a vibration wave motor, which enables proper frequency control of an AC voltage applied to the motor according to the rotational speed difference between the actual and target rotational speeds of the motor, even if frequency-rotational speed characteristics are not stored in advance. A target rotational speed of a moving member is set. A ratio of an amount of increase or decrease in a rotational speed of the moving member to an amount of update of a frequency of the AC voltage and a rotational speed difference between the target rotational speed and an actual rotational speed of the moving member are calculated. The amount of update of the frequency is calculated by dividing the calculated rotational speed difference by the calculated ratio. The frequency of the AC voltage is updated by using the calculated amount of update of the frequency.

Abstract: A drive unit includes an ultrasonic actuator having an actuator body formed using a piezoelectric element, and a driving element provided on the actuator body and configured to output a driving force by moving according to the vibration of the actuator body, and a control section configured to induce the vibration in the actuator body by applying a first and a second AC voltages having a same frequency and different phases to the piezoelectric element. The control section adjusts the first AC voltage and the second AC voltage so that the first AC voltage and the second AC voltage have different voltage values from each other.

Abstract: Disclosed is an electronic component bonding method which interposes a bonding resin between first and second electronic components to bond the first and second electronic components to each other. The electronic component bonding method includes providing the bonding resin between the first and second electronic components, aligning the first and second electronic components with each other, pre-curing the bonding resin to generate elasticity in the bonding resin, performing a main curing operation to apply vibration energy to the bonding resin, which has elasticity according to pre-curing, to securely fix the first and second electronic component to each other, and control the amplitude of the vibration energy applied during the main curing operation to be restricted within an elastic region of the bonding resin.

Abstract: In accordance with particular embodiments, a system for displaying modulated light includes a spatial light modulator comprising a plurality of micromirrors having a pixel pitch less than 17 micrometers. The system also includes an intermediate voltage generator operable to generate a negative voltage and a positive voltage. The system further includes at least two level shifters coupled to the intermediate voltage generator. The system additionally includes a reset driver coupled to the at least two level shifters and to at least a subset of the plurality of micromirrors. The reset driver is operable to drive the subset of the micromirrors. The spatial light modulator, the intermediate voltage generator, the at least two level shifters, and the reset driver are all incorporated on a common substrate.

Abstract: An electrostatic drive having at least three intermediate frames, each two adjacent intermediate frames being connected to one another via at least one intermediate spring whose longitudinal directions lie on a first axis of rotation, and intermediate electrode fingers being situated on frame girders oriented parallel to the first axis of rotation of the intermediate frames, and having an outer frame that surrounds the intermediate frames and that is connected to the outermost intermediate frame via at least one outer spring whose longitudinal direction lies on a second axis of rotation that is oriented non-parallel to the first axis of rotation, and outer electrode fingers being situated on frame girders oriented parallel to the second axis of rotation of the outer frame and of the outermost intermediate frame of the at least three intermediate frames.

Abstract: The present invention provides a system and method of piezoelectric fault recovery comprising: monitoring a set of operational piezoelectric elements of a piezoelectric actuator, detecting a failure of an element of the set, removing the failed element from the set, and rerouting the drive signal sent to the element according to a predetermined behavior preference.

Abstract: A micro-electro mechanical device includes a first structure, a second structure offset from the first structure by a gap. The first structure is configured to be electrostatically actuated to deflect relative to second structure. A pulse generator is configured to combine at least two different pulses to electrostatically drive at least one of the first structure and the second structure between an initial position and a final position.

Abstract: A multi-element piezoelectric actuator and driver is presented that allows greater control over the dynamic displacement response of a piezoelectric actuator. A system comprises a piezoelectric driving apparatus configured to transmit a plurality of waveform signals to a corresponding plurality of piezoelectric elements of a piezoelectric actuator. The piezoelectric driving apparatus comprises a waveform generator to generate a waveform configured to operate a piezoelectric element, a plurality of channels coupled to the waveform generator and configured to be electrically coupled the piezoelectric elements of the piezoelectric actuator, a channel comprising an input configured to receive a waveform, a driving amplifier electrically coupled to the input and configured to amplify the waveform, and an output configured to transmit the waveform and configured to be electrically coupled to a piezoelectric element.

Abstract: A vibration actuator driving device includes a plurality of wiring sections and a supply controller. The plurality of wiring sections are disposed correspondingly to a plurality of electrically independent electrodes of an electromechanical conversion element. The wiring sections input driving signals to drive the electromechanical conversion element. The supply controller is capable of independently supplying a driving signal for each respective wiring section.

Abstract: A piezoelectric vibration device system includes a piezoelectric vibration device that performs predefined movements using the vibration of the piezoelectric element; and a control unit that controls the behavior of the piezoelectric vibration device by controlling the frequency of the piezoelectric element, where the control unit includes: a first signal generating unit that generates a fundamental frequency signal having a fundamental frequency adjacent to the mechanical resonance frequency of the piezoelectric element; a second signal generating unit that generates a variable frequency signal whose frequency periodically rises or falls; and a frequency modulator that generates a frequency modulated signal, whose frequency changes into one of three or more frequencies existing around the fundamental frequency periodically and in sequence, by executing frequency modulation using the fundamental frequency signal and the variable frequency signal, and that outputs the frequency modulated signal as a control si

Abstract: A system and method for defining a signal for driving a piezoelectric actuator, comprising defining a wave profile corresponding to a voltage waveform of a signal for actuating a piezoelectric actuator; modifying the wave profile such that an operational profile of the piezoelectric actuator is adjusted; and providing the signal to the piezoelectric actuator to operate the piezoelectric actuator.

Abstract: A micromechanical component includes a first electrode and a second electrode, the first electrode being moveable relative to the second electrode in a main direction of movement, and the first electrode and/or the second electrode being configured such that a movement of the first electrode parallel to the main direction of movement results in a modification of the average distance in a region of overlap of the projection of the first electrode with the projection of the second electrode, both perpendicular to the main direction of movement and in a main plane of extension.

Abstract: An electrostatic actuator and a method of driving the same are provided. The actuator controls the displacement of a target object by adjusting a voltage between fixed comb electrodes and a moving comb electrode. The actuator includes an actuator control signal generator generating an actuator control signal by pulse-width modulating an actuator driving signal and a carrier signal; and an actuator unit including the fixed comb electrodes and the moving comb electrode and adjusting the voltage according to the actuator control signal. Accordingly, the displacement can be easily controlled using the pulse-width-modulated actuator driving signal even when both the voltage of the actuator driving signal and the frequency of the carrier signal are high.

Abstract: An active scanner bow compensator for use with a scanner is described. The scanner includes a moveable scanning platform supported within a frame. The active scanner bow compensator supports the scanner and includes a frame of reference, sensors, and an actuator. The sensors detect out-of-plane motion of the scanning platform relative to the frame of reference, and the actuators compensate for the out-of-plane motion by adjusting the orientation of the frame relative to the frame of reference. The active scanner bow compensator may be used in atomic force microscopy applications.

Abstract: A resonator includes a translator, a stator, and a control circuit. The control circuit is configured to provide first and second translator voltages and first through third stator voltages, wherein the translator is configured to move with respect to the stator at a resonant frequency of the resonator in response to the control circuit.

Abstract: A piezo-actuator is actuated in a first operating mode (B1) by pulsed supply of a first electrical variable for charging or discharging of the piezo-actuator taking into account at least one actuation parameter (P) for the piezo-actuator. The piezo-actuator is actuated in a second operating mode (B2) by non-pulsed introduction of the first electrical variable for charging or discharging of the piezo-actuator, to be precise with the first electrical variable having a predetermined profile which is substantially independent of any load change on the piezo-actuator (1). A profile of a second electrical variable of the piezo-actuator is recorded during at least one measurement time period while the predetermined profile of the first electrical variable is being applied. The at least one actuation parameter (P) of the piezo-actuator is determined as a function of the recorded profile of the second electrical variable.

Abstract: An electrostatic actuator comprising: first and second comb arrays of electrodes arranged on a base, the electrodes of the first and second comb arrays being interleaved; a third comb array of electrodes spring mounted over the first and second comb arrays, the electrodes of the third comb array being essentially aligned with the electrodes of the second comb array; means for applying a first voltage to the third comb array and a second voltage to the first and second comb arrays to generate an attractive force acting on the third comb array to move the third comb array toward the second comb array; and, means for applying the first voltage to the second and third comb arrays and the second voltage to the first comb array to generate a repulsive force acting on the third comb array to move the third comb array away from the second comb array.

Abstract: A micromechanical element includes a movable functional element, a first retaining element, a second retaining element, a third retaining element, and a fourth retaining element. The first retaining element and the functional element are connected at a first junction, the second retaining element and the functional element are connected at a second junction, the third retaining element and the functional element are connected at a third junction, and the fourth retaining element and the functional element are connected at a fourth junction. In addition, the first retaining element and the second retaining element each include a piezoelectric driving element, the driving element of the first retaining element and the driving element of the second retaining element being configured to move the functional element in accordance with electric excitation.

Abstract: A micro-oscillation element includes a movable main section, a first frame and a second frame, and a first connecting section that connects the movable main section and the first frame and defines a first axis of rotation for a first rotational operation of the movable main section with respect to the first frame. The element further includes a second connecting section that connects the first frame and the second frame and defines a second axis of rotation for a second rotational operation of the first frame and the movable main section with respect to the second frame. A first drive mechanism is provided for generating a driving force for the first rotational operation. A second drive mechanism is provided for generating a driving force for the second rotational operation. The first axis of rotation and the second axis of rotation are not orthogonal.

Abstract: A drive circuit comprising: a direct current power source; a control unit for supplying control signals; a power switch topology comprising a first switch and a second switch each having an input terminal, an output terminal, and a control terminal, the input terminals being respectively connected to the power source, the control terminals being connected to the control unit for receiving the control signals there from, the output terminals being connected to a node; and an inductance connected with a capacitive load in series between the node and the power source, wherein the control signals control the switches to alternately conduct to thereby cause the node to output a pulse signal.

Abstract: A control device for an ultrasonic piezoelectric actuator including a first stage supplied by a DC voltage source and including a mechanism forming a second DC voltage above that voltage delivered by the DC voltage source, and a second stage including a mechanism amplifying the second voltage and chopping the voltage obtained by excitation of the actuator with the chopped voltage, under control of a computer. The amplifying mechanism includes an inductor in electrical resonance with the piezoelectric actuator. The inductor is connected to the first stage so as to constitute, during formation of the second voltage, a secondary winding of a transformer forming part of a flyback voltage converter introduced into the first stage to develop the second voltage. The control device may find application to control of a fuel injector in an internal combustion engine.

Abstract: A stepper motor driving a driven member is calibrated by periodically driving the member from its current operational position to an end stop of the driven member's total travel range; however, the driven member approaches the end stop in a series of ever-shorter travel segments. The first travel segment is less than ? the total travel range to compensate for a possible sudden speed reversal, which can be accidentally triggered by the driven member reaching and “bouncing off” the end stop. Limiting the commanded first travel segment to less than ? the total travel range prevents the driven member from reaching an opposite travel limit should the driven member suddenly reverse direction at three times the normal forward speed, wherein such triple speed is characteristic of reverse-speed situations.

Abstract: The invention relates to a micro-electro-mechanical system comprising a ciliary actuator (100) having a flexible electrode unit (FE) and a stationary electrode unit (SE), wherein the flexible electrode unit (FE) can be rolled-up or out according to a voltage (VPMA) applied between the flexible and the stationary electrode unit (SE). The invention provides means that allow to bring the actuator into a stable intermediate state (INT) between the totally rolled-up (UP) and the totally rolled-out (DWN) state. In one embodiment of the invention, the means comprise the application of a definite voltage and/or the transfer of a definite charge to the actuator. In another embodiment, the stationary electrode unit (SE) is composed of several segments of different drive electrodes (SE1, SE2) that can selectively be activated to roll the actuator (100) to a desired position.

Abstract: Electrostatic microactuators are described in which stationary electrodes (4) and movable electrodes (3) mounted on flexures (6) have relative locations and mechanical properties such that non-linear pull-in/pull-out behavior is displayed when a voltage is applied between the stationary electrodes (4) and the electrodes do not come into contact. Larger electrostatic forces and longer travel ranges are achievable with lower applied voltages than typical microactuators. Further advantageous properties are obtained with the application of time-varying voltages with peak values exceeding the pull-in voltage and also at frequencies near a resonant frequency of the device. Several applications are described.

Abstract: A microcomputer that controls an ultrasonic motor includes a storage unit that stores a compare register value, and a digital/analog (D/A) conversion set value, a D/A converter that generates an amplitude control signal with an amplitude value corresponding to the D/A conversion set value, a timer that generates a pulse width modulation (PWM) signal with a frequency corresponding to the compare register value, a central processing unit (CPU) that reads the D/A conversion set value, and the compare register value from the storage unit, and that sets the D/A conversion set value and the compare register value to the D/A converter and the timer, respectively, and an output circuit that generates the control signal with the amplitude of the amplitude control signal, and the frequency of the PWM signal, in response to the amplitude control signal and the PWM signal.

Abstract: According to the present invention, a moving element such as an electrostatically driven actuator is displaced by supplying a drive signal thereto. Meanwhile, a displacement sensing section senses its displacement and a calibrating section automatically calibrates the correlation between the drive signal and the displacement, thereby compensating for a variation in the characteristic of the actuator with time and according to the environment. A switching section selectively connects the single displacement sensing section to a plurality of moving elements one after another, thereby cutting down the circuit for displacement sensing.

Abstract: A driver for electrically causing a MEMS device to change shape or position includes an amplifier having a first feedback loop and a second feedback loop. The first feedback loop stabilizes output voltage and the second feedback loop reduces current changes through the MEMS device to zero.

Abstract: An actuator and method for MEMS array actuation is disclosed. In one embodiment, the actuator having a pixel coupled to a charge integration circuit, the pixel comprising a voltage bias, a variable gap capacitor, and a switch, all in series, the charge integration circuit configured to modulate charge on the variable gap capacitor during an actuation cycle. In one embodiment, the MEMS actuator having a unit cell with parasitic capacitance and coupled to a negative feedback sampling circuit, the unit cell comprising a variable gap capacitor, a voltage bias, a modulated current source, and a voltage-to-current converter, the negative feedback sampling circuit configured to receive an output current from the unit cell, convert the output current from the unit cell to a low voltage signal, sample the low voltage signal, and provide a feedback signal to the modulated current source to compensate for the parasitic capacitance in the unit cell.

Abstract: An electric circuit for triggering a piezoelectric element, in particular of a fuel injection system of a motor vehicle. Two transistors connected in series and triggerable using a clock pulse are provided, whose shared connecting point is coupled to the piezoelectric element and one of which is provided for discharging the piezoelectric element. In the event of an error, the transistor provided for discharging can be triggered using the clock pulse.

Abstract: An electrostatic actuator includes a stator having a plurality of protruding electrodes formed on a surface of a base material, where the surface serves as a counter surface, and a mover disposed so as to face the stator, where the mover has a plurality of protruding electrodes formed on a surface of a base material and the surface serves as a counter surface. A side surface of each of the protruding electrodes of the stator faces a side surface of a corresponding one of the protruding electrodes of the mover. Planar electrodes are formed on at least one of the counter surface of the stator and the counter surface of the mover in a portion other than a portion where the protruding electrodes are formed, and the planar electrodes face end surfaces of the protruding electrodes formed on the other counter surface.

Abstract: A micro-oscillation element includes a movable main section, a first frame and a second frame, and a first connecting section that connects the movable main section and the first frame and defines a first axis of rotation for a first rotational operation of the movable main section with respect to the first frame. The element further includes a second connecting section that connects the first frame and the second frame and defines a second axis of rotation for a second rotational operation of the first frame and the movable main section with respect to the second frame. A first drive mechanism is provided for generating a driving force for the first rotational operation. A second drive mechanism is provided for generating a driving force for the second rotational operation. The first axis of rotation and the second axis of rotation are not orthogonal.

Abstract: Methods and apparatuses for sensing and adjusting lateral motion in a comb drive actuated MEMS device are provided. If lateral motion is sensed by a lateral motion sensor coupled to the comb drive actuated MEMS device, and the lateral motion is greater than a reference value, a feedback controller adjusts the lateral motion by providing a drive signal to a comb drive electrode of a comb drive actuator.

Abstract: A semiconductor device controls an electrostatic actuator having first and second electrodes formed so as to come close to each other when transition occurs from opened state to closed state by electrostatic attraction against elastic force. The semiconductor device includes: a voltage generation unit generating different applied voltages to be applied to the first and second electrodes; a control unit controlling the voltage generation unit to switch the applied voltages; and a detection unit detecting voltage of the first or second electrode or a rate of change in the voltage. The control unit controls a target voltage of the voltage generation unit to be switched from a first voltage to a second voltage lower than the first voltage according to a detection output by the detection unit.

Abstract: An electrostatic actuator includes a stator that includes a stator-side electrode group including a plurality of electrodes, a mover that includes a mover-side electrode group including a plurality of electrodes and that can move in a predetermined movement direction, this plurality of electrodes opposing the electrodes in the stator-side electrode group, a guide instrument that guides the mover, and a driving signal supply unit that generates driving signals and applies the driving signals between the stator-side electrode group and the mover-side electrode group. In one electrode group of these electrode groups, the electrodes and gaps have the same length and are alternately disposed in the movement direction, and the other electrode group includes a first group and a second group alternately disposed in the movement direction, each of the first and second groups including an electrode and a gap.

Abstract: An electrostatic actuator having a simple structure including a reduced number of systems that supply driving voltages and a method for driving the electrostatic actuator. Stator electrodes 23 including a plurality of electrical systems (A-phase electrodes, B-phase electrodes, and C-phase electrodes) are repeatedly disposed in a predetermined order in the moving direction. A pitch (cycle length) 3P1 of the stator electrodes 23 that forms the electrical systems of the same type in the moving direction is equal to a pitch c of the mover electrodes 33 in the moving direction, and the mover includes at least two types of mover electrodes 33a1 and 33b1 having different lengths.

Abstract: A sub-module consists of a set of two outer sets of stationary fan-blade-shaped sectors. These outer sectors include conductive material and are maintained at ground potential in several examples. Located midway between them is a set of stationary sector plates with each plate being electrically insulated from the others. An example provides that the inner sector plates are connected together alternately, forming two groups of parallel-connected condensers that are then separately connected, through high charging circuit resistances, to a source of DC potential with respect to ground, with an additional connecting lead being provided for each group to connect their output as an AC output to a load. These same leads can he used, when connected to a driver circuit, to produce motor action.

Abstract: There is provided a method of driving an ultrasonic motor configured so that two alternating voltages having a predetermined difference between respective phases and having predetermined drive frequencies are applied to a laminated piezoelectric body that has driving parts abutting a member to be driven, whereby simultaneous excitation of vertical and bending vibrations and hence excitation of an elliptical vibration occur in the piezoelectric body, and the driving parts receiving drive force from the elliptical vibration drive the driven member. The method includes performing wear particle removal drive at a fixed frequency during regular reciprocal drive so as to intermittently interrupt the regular drive, the regular drive being such that the driving parts repeatedly reciprocally drive the driven member within a predetermined range, and the wear particle removal drive being such that the driving parts reciprocally drive the driven member within a removal drive range wider than the predetermined range.

Abstract: A MEMS device uses both piezoelectric actuation and electrostatic actuation and also provides enough electrostatic force to enable very low voltage operation. As the electrostatic actuation uses DC and the piezoelectric actuation uses high frequency, the structure of the device minimizes the coupling of the two actuator structures to reduce noise. In addition, for some embodiments, the location of the physical structures of the piezoelectric actuator and electrostatic actuator generates higher contact force with lower voltage. For some embodiments, the piezoelectric actuator and electrostatic actuator of the device are connected at the contact shorting bar or capacitor plate location. This makes the contact shorting bar or capacitor plate the focal point of the forces generated by all of the actuators, thereby increasing the switch contact force.

Abstract: The present invention provides an electrostatic actuator having a small power consumption and also provides a driving method thereof. The electrostatic actuator comprises first and second substrates having first and second stator electrodes formed thereon, respectively, and a movable section arranged between the first and second stator electrodes. The movable section has first and second surfaces that are positioned to face the first and second stator electrodes, respectively. In first and second moving modes, the movable section is slightly moved between the first and second substrates in response to the signal voltage from the driving circuit. Also, in the holding mode, the movable section is held by one of the first and second stator electrodes and, under this condition, at least one of the stator electrode holding the movable section and the movable section held by the stator electrode is left electrically floating.