In one embodiment, an electrostatic actuator includes a generally planar fixed frame, a generally planar moving frame coupled to the fixed frame by a flexure for substantially coplanar, perpendicular movement relative to the fixed frame, a plurality of interdigitated teeth, a fixed portion of which is attached to the fixed frame and a moving portion of which is attached to the moving frame, and an elongated output shaft having opposite input and output ends, the input end being coupled to the moving frame.

An electret element includes: an Si layer, an SiO.sub.2 layer formed at a surface of the Si layer; and an electret formed at the SiO.sub.2 layer near an interface of the SiO.sub.2 layer and the Si layer.

The invention relates to a device including: a movable element (1) comprising teeth (11; 11.sub.i, i, 11.sub.i+1, 11.sub.i+2, 11.sub.i+3, 11.sub.i+4); a driving element (2) for engaging with the teeth (11; 11.sub.i, 11.sub.i+1, 11.sub.i+2, 11.sub.i+3, 11.sub.i+4) of the movable element (1) so as to set the movable element (1) in motion in a direction of movement; an actuator element (3) capable of generating an alternating movement so as to move the driving element (2) according to at least two phases, i.e. a driving phase, during which the driving element (2) is engaged with a tooth (11; 11.sub.i, 11.sub.i+1, 11.sub.i+2, 11.sub.i+3, 11.sub.i+4) of the movable element (1), and a return phase without driving, during which the driving element (2) is shifted with respect to the movable element (1); and a first indexing element (4), which includes a first indexing finger (41) to be positioned between two teeth (11; 11.sub.i, 11.sub.i+1, 11.sub.i+2, 11.sub.i+3, 11.sub.i+4) of the movable element (1), and which is connected to the actuator element (3) in order to move the driving element (2) and the first indexing finger (41) simultaneously.

A microelectromechanical systems (MEMS) device may be provided with one or more sintered electrical contacts. The MEMS device may be a MEMS actuator or a MEMS sensor. The sintered electrical contacts may be silver-paste metalized electrical contacts. The sintered electrical contacts may be formed by depositing a sintering material such as a metal paste, a metal preform, a metal ink, or a metal powder on a wafer of released MEMS devices and heating the wafer so that the deposited sintering material diffuses into a substrate of the device, thereby making electrical contact with the device. The deposited sintering material may break through an insulating layer on the substrate during the sintering process. The MEMS device may be a multiple degree of freedom actuator having first and second MEMS actuators that facilitate autofocus, zoom, and optical image stabilization for a camera.

[Object] To make it possible to selectively switch the threshold value of the drive voltage.

[Solution] Provided is an electrostatic actuator, including: a base section; a movable electrode section held to be displaceable in a predetermined direction with respect to the base section; and a plurality of fixed electrodes fixed to the base section to be separated from the movable electrode section along a movable direction of the movable electrode section and face the movable electrode section, the plurality of fixed electrodes being electrically separated from each other. The electrostatic actuator is driven in accordance with a drive voltage selectively applied to the plurality of fixed electrodes and a voltage value of the drive voltage.

An optical device includes: a base; a movable portion including an optical function portion; an elastic support portion supporting the movable portion so that the movable portion is movable along a first direction; a first comb electrode provided to the base and including a plurality of first comb fingers; and a second comb electrode including a plurality of second comb fingers. The elastic support portion includes a torsion bar extending along a second direction perpendicular to the first direction and a lever. The second comb electrode is provided to a portion of at least one of the movable portion and the elastic support portion, the portion being located on the optical function portion side with respect to the torsion bar. The first comb finger and the second comb finger adjacent to each other face each other in a direction in which the movable portion has higher external force resistance, of the second direction and a third direction perpendicular to the first direction and the second direction.

An optical device includes a support portion, a movable portion; and a pair of torsion bars. An optical function portion is provided on one surface of the movable portion and a rib portion is provided on the other surface of the movable portion. The rib portion includes eight extending portions of first to eighth extending portions. When setting directions in which the first to eighth extending portions extend as first to eighth extending directions respectively, and setting an angle between the first and second extending directions as a first angle, an angle between the third and fourth extending directions as a second angle, an angle between the fifth and sixth extending directions as a third angle, and an angle between the seventh and eighth extending directions as a fourth angle, each of the first and second angle is larger than each of the third and fourth angle.

A microelectromechanical system (MEMS) device comprising a wafer including a MEMS device in a substrate of the wafer is mounted to a fluid dispenser stage. The MEMS device has a damping structure coupled to a suspended element and one or more fluid confinement structures. The suspended element is connected to a fixed part of the substrate by one or more flexures configured to permit movement of the suspended element relative to the fixed part of the substrate. The damping structure extends into a gap between the suspended element and fixed part of the substrate. The fluid confinement structures permit movement of the damping structure within a limited portion of the gap and confine a viscoelastic fluid to the limited portion of the gap. A viscoelastic fluid is deposited onto the wafer in an area of the wafer configured to communicate the viscoelastic fluid into the limited portion of the gap.

To provide a simply-structured multilayer electrostatic actuator that exhibits a sufficient stroke and a sufficient contraction force in a specific drive range, and rapidly hardens upon an attempt to widen the interval between electrodes beyond the drive range. A multilayer electrostatic actuator (1) is configured by a plurality of actuator parts (2a, 2b, 2c) each including: a first film (3a.sub.1, 3b.sub.1, 3c.sub.1) having a plurality of first connection regions (7a.sub.1, 7b.sub.1, 7c.sub.1) formed on one surface in a predetermined pattern; and a second film (3a.sub.2, 3b.sub.2, 3c.sub.2) connected to the first film via the first connection regions, and having a plurality of second connection regions (7a.sub.2, 7b.sub.2, 7c.sub.2) formed on a surface opposite to the first film in the identical pattern. The actuator parts are connected and layered via the second connection regions. On both the first film and the second film of one actuator part (2a, 2b, 2c), a non-connection region (15) is formed having a substantially fixed width between connection regions adjacent to each other as viewed in a layering direction (Z). The first connection regions and the second connection regions are arranged so as not to overlap each other as viewed in the layering direction. Axes of the patterns between two actuator parts (2a, 2b; 2b, 2c) connected intersect each other at a predetermined angle (, except =0) as viewed in the layering direction. When the multilayer electrostatic actuator is pulled in the layering direction due to an external force, the non-connection region, in particular mainly the non-connection region of the second film, is bending-deformed to separate the first film and the second film, resulting in the multilayer electrostatic actuator extending in the layering direction. Further pulling makes the non-connection region tensile-deformed and hardened. When a voltage is applied, the multilayer electrostatic actuator contracts in the layering direction due to the electrostatic attractive force.

A MEMS actuator including buckled flexures and a method of assembling the actuator are described. The assembled MEMS actuator includes an inner frame; an outer frame including latched electrical bars, where a first of the latched bars includes a latch protrusion secured to a corresponding latch groove of a second of the latched bars; and buckled flexures coupling the inner frame to the outer frame. The flexures are buckled during assembly of the MEMS actuator by incorporating the electrical bar latching mechanism into the design of the outer frame of the MEMS actuator. In one implementation, the MEMS actuator is assembled by providing a MEMS actuator with unbuckled flexures coupling the outer frame of the MEMS actuator to an inner frame of the MEMS actuator, where the outer frame includes unlatched electrical bars, and latching the electrical bars of the outer frame, resulting in buckled flexures.