Abstract: First and second wafers are micromachined by standard integrated-circuit fabrication techniques to respectively make first and second component parts of a variable capacitor. A thin flexible membrane in the first wafer is integral with and mechanically supported by the first wafer. A metal pattern on the first wafer includes a first capacitor plate on the membrane. In the second wafer, a well is formed. A metal pattern on the second wafer includes a second capacitor plate in the well. By bonding the two parts together face-to-face, the capacitor plates are positioned in spaced-apart alignment with each other. External electrical connections to the plates are made via bonding-pad portions of the metal patterns on the wafers. In response to electrical control signals, the metal plate on the membrane can be moved toward the other plate, thereby selectively changing the capacitance of the assembly.

Abstract: An electronic component includes a support substrate (101), a fixed electrode (113) overlying the support substrate (101), a movable electrode (123, 423) overlying the support substrate and the first electrode (113) wherein the first and second electrodes (113, 123, and 423) form a capacitor with a sensing area, an anchor (122, 422) coupled to the support substrate (101), and beams (125, 425) coupling different attachment points (129) of the second electrode (123, 423) to the anchor (122, 422) wherein the different attachment points (129) form a simply connected polygon and wherein a portion of the sensing area is located within the simply connected polygon.

Abstract: A precision, micro-mechanical semiconductor accelerometer of the differential-capacitor type comprises a pair of etched opposing cover layers fusion bonded to opposite sides of an etched proofmass layer to form a hermetically sealed assembly. The cover layers are formed from commercially available, Silicon-On-Insulator ("SOI") wafers to significantly reduce cost and complexity of fabrication and assembly. The functional semiconductor parts of the accelerometer are dry-etched using the BOSCH method of reactive ion etching ("RIE"), thereby significantly reducing contamination inherent in prior art wet-etching processes, and resulting in features advantageously bounded by substantially vertical sidewalls.

Abstract: A variable capacitor includes a first electrode (2), a second electrode (3) and, located between the first and second electrodes, an array of gas discharge tubes (7). The capacitor includes means for producing an electrical discharge in the tubes, thereby affecting the capacitance of the capacitor.

Abstract: A semiconductor pressure sensor utilizing electrostatic capacitance has a plurality of pressure sensing electrostatic capacitances and a reference electrostatic capacitance formed on one side of a silicon chip. As a movable electrode, the pressure sensing electrostatic capacitances each have a diaphragm, which may have a displacement portion composed of a central area thereof, and a peripheral portion which is more deformable than the central portion.

Abstract: In a sensor and a method for manufacturing a sensor, a movable element is patterned out of a silicon layer and is secured to a substrate. The conducting layer is subdivided into various regions, which are electrically insulated from one another. The electrical connection between the various regions of the silicon layer is established by a conducting layer, which is arranged between a first and a second insulating layer.

Abstract: A microfabricated gyroscope to measure rotation about an axis perpendicular to the surface of the substrate. The driving electrodes, X-axis sensing electrodes, and Y-axis sensing electrodes may all be fabricated from a signal structural layer. The gyroscope includes movable sensing electrode fingers which are positioned between paired stationary sensing electrode fingers. The position of the proof mass along the Y-axis is measured by a capacitive bridge. A voltage differential may be applied between the pairs of stationary electrode fingers to reduce the quadrature error, and a bias voltage may be applied between the movable and stationary electrode fingers to adjust the Y-axis resonant frequency.

Abstract: A semiconductor physical quantity sensor includes a substrate and a beam structure having movable electrodes and spacing a given distance from an upper surface of the substrate. First fixed electrodes and second fixed electrodes are fixedly provided on the upper surface of the substrate. Each first fixed electrode faces one side of the corresponding movable electrode, while each second fixed electrode faces the other side of the corresponding movable electrode. A laminated structure of a lower layer insulating film, conductive films and an upper layer insulating film is arranged at an upper portion of the substrate. The conductive layers form a first wiring pattern for the first fixed electrodes, a second wiring pattern for the second fixed electrodes and a lower electrode. The first wiring pattern is electrically connected to the first fixed electrodes via openings formed in the upper layer insulating film and anchors of the first fixed electrodes, respectively.

Abstract: A micromechanical component includes a one-piece surface structure that is created on a substrate. The one-piece surface structure is attached to the surface of the substrate by at least two anchoring areas. The anchoring areas are a small distance apart, which is comparatively small in comparison with the lateral dimension of the surface structure. The surface structure has movable electrodes. Opposite them there are rigid electrodes that are attached to the substrate by additional anchoring areas. The additional anchoring areas also have a small distance between one another and to the anchoring areas.

Abstract: A variable capacitor in a semiconductor device is described in which the capacitance is varied by the movement of a dielectric material in the space between the plates of the capacitor in response to an external stimulus. A method of making such a variable capacitor is also described in which the capacitor is built in a layered structure with the top layer including a portion of dielectric material extending into the space between the capacitor plates. After formation of the top layer, an intermediate layer is etched away to render the top layer flexible to facilitate movement of the dielectric material in the space between the capacitor plates.

Abstract: A protective coating is utilized to protect the silicon during a wet chemical etch step in the process of making a micromachine, thereby preventing the formation of etched holes or pits in the micromachine. In another embodiment, silicon sacrificial pedestals are used to eliminate or greatly reduces the electrical potential difference between metal on the glass substrate and the silicon, thereby eliminating arcing and the resulting damage to silicon and metal. These pedestals may be removed after the anodic bond.

Abstract: Fixed electrodes (A through F) are formed by means of a structural layer that has been provided on fixed bodies (7.sub.1 through 7.sub.4) of a silicon micro-machined substrate and a movable electrode (G) is formed by a movable body attached to fixed bodies (5.sub.1 through 5.sub.4) by flexible members (6.sub.1 through 6.sub.4). Variable capacitors of the parallel plate-type are formed by the movable electrode (G) and the fixed electrodes (A through F). When the movable electrode (G) has been vibrated, the Coriolis force incident to rotation or the force incident to acceleration are added to the movable electrode (G), with a result that the charge of the various variable capacitors change. By detecting the change in charge, both angular velocity and acceleration can be obtained. By providing another variable capacitor formed by a mass portion (H) by a movable body and the substrate, acceleration components in the directions of three axes can be detected.

Abstract: The component has a movable section (2) over a substrate (1), in which spacers (3) preferably made of fluorocarbon are present on the top side of the substrate and prevent the movable section from adhering to the support.

Abstract: A micromachined device is provided that establishes select dimensional relationships between micromachined structures to achieve correlation in dimensional variation among these structures. Such dimensional relationships are achieved through consistent spacing between desired operating structures and by adding new structures (i.e., dimensional control structures) which provide additional consistent spacing at desired locations within the micromachined device.

Abstract: The capacitance type gaseous sensing device (10) includes a first electrode layer (12) formed on a semiconductor substrate layer (14). A seed layer (16) is formed on the first electrode layer (12). A reorganized layer (18) is formed on the first electrode layer (12) through interaction with the seed layer (16) to form a porous sensing layer. A second electrode layer (20) is formed on the reorganized layer (18). The reorganized layer (18) absorbs gaseous elements that change the dielectric constant of the capacitance type sensor device (10). A change in the dielectric constant causes a change in the capacitance of the reorganized layer (18) as measured across the first electrode layer (12) and the second electrode layer (20).

Abstract: A monolithic capacitance-type microstructure includes a semiconductor substrate, a plurality of posts extending from the surface of the substrate, a bridge suspended from the posts, and an electrically-conductive, substantially stationary element anchored to the substrate. The bridge includes an element that is laterally movable with respect to the surface of the substrate. The substantially stationary element is positioned relative to the laterally movable element such that the laterally movable element and the substantially stationary element form a capacitor. Circuitry may be disposed on the substrate and operationally coupled to the movable element and the substantially stationary element for processing a signal based on a relative positioning of the movable element and the substantially stationary element. A method for fabricating the microstructure and the circuitry is disclosed.

Abstract: The capacitance type gaseous sensing device (10) includes a first electrode layer (12) formed on a semiconductor substrate layer (14). A seed layer (16) is formed on the first electrode layer (12). A reorganized layer (18) is formed on the first electrode layer (12) through interaction with the seed layer (16) to form a porous sensing layer. A second electrode layer (20) is formed on the reorganized layer (18). The reorganized layer (18) absorbs gaseous elements that change the dielectric constant of the capacitance type sensor device (10). A change in the dielectric constant causes a change in the capacitance of the reorganized layer (18) as measured across the first electrode layer (12) and the second electrode layer (20).

Abstract: A capacitive sensor for measuring accelerations and inclinations with respect to the gravitational field. The capacitive sensor has at least one stator electrode and one displacement electrode, in which the position of the displacement electrode can change with respect to the stator electrode, thereby resulting in a change in capacitance. From this change of capacitance, an acceleration or inclination can be measured. The capacitive sensor is distinguished by the stator electrode being designed to have an annular shape and the displacement electrode is likewise formed by an annular element which is connected to a central surface part via resilient elastic webs, and wherein the central surface part is immovably connected to the sensor housing. Alternatively, the capacitive sensor may have the stator electrode and the displacement electrode formed as polygonal shapes.

Abstract: A first embodiment of a condition responsive capacitive transducer, such as an accelerometer (1), is shown in which an electrically conductive sensor element (14) is sandwiched between upper (10) and lower (12) electrically insulative planar substrates and mounted in sealed, spaced apart relation by patterns (16) of adhesive containing spacing elements. A second embodiment (100) includes a signal conditioning capacitor having plate portions (114r, 120b and 114s, 120c) on either side of a condition responsive capacitor to minimize errors caused by translational movement of the sensor element (114) relative to the substrates (110, 112). Circuit conditioning electronics (124) is shown mounted directly on one of the substrates (110) and the sensor is mountable directly on a circuit board. A third embodiment (200) shows differential capacitors (224, 226, 228, 230, 232, 234) for minimizing errors due to misalignment of the movable element (114) with respect to the fixed supports (210, 212).

Abstract: An accelerometer having one or more flexure stops for increasing the stiffness of the flexures when the accelerometer is subjected to relatively high acceleration. A wrap-around proof mass is suspended over a substrate by anchor posts and a plurality of flexures. In one embodiment, the proof mass has a rectangular frame including top and bottom beams extending between left and right beams and a central crossbeam extending between the left and right beams. Proof mass sense electrodes are cantilevered from the top, bottom and central beams and are interleaved with excitation electrodes extending from adjacent excitation electrode supports. Each of the flexure stops includes a pair of members extending along a portion of a respective flexure. Also described is a three axis accelerometer triad device and a dissolved wafer process for fabricating the devices described herein.

Abstract: A condition responsive capacitive transducer, such as an accelerometer, is shown using a material system having refractory metal for the sensing element and glass material for a supporting substrate. The refractory metal is preferably tungsten, tantalum or molybdenum, and is coated with a glass seal enhancing material, such as titanium or nickel.

Abstract: In a sensor and a method for manufacturing a sensor, a movable element is patterned out of a silicon layer and is secured to a substrate. The conducting layer is subdivided into various regions, which are electrically insulated from one another. The electrical connection between the various regions of the silicon layer is established by a conducting layer, which is arranged between a first and a second insulating layer.

Abstract: The integrated electronic sensor for characterizing physical quantities comprises a substrate (5) having a characterizing member (3) and a cover (9) maintained in the vicinity of and in front of the characterizing member (3) by means of at least one ball (11) bearing on the substrate (5), so as to provide a first spacing between the cover (9) and the substrate and is characterized in that the cover has a boss (15) facing the characterizing member (3) so as to define a second spacing between the cover (9) and the member, which is smaller than the spacing between the cover and the substrate.

Abstract: An accelerometer having a pair of spaced apart planar electrodes in a housing wherein one of the planar electrodes is made of a thin film and has a mass attached to one side such that acceleration causes the thin film to flex. A solid state amplifier is located in the housing attached to one of the planar electrodes to measure the change in capacitance caused by the flexing of the thin film. The solid state amplifier may be an NPN transistor. The mass may be a 4.5 mm steel airgun shot, and the thin film may be 1 mil polyester aluminized metallic film. The output of the accelerometer is connected to one input of a operational amplifier, and the other input of the operational amplifier is connected to a transducer measuring ambient noise such that the ambient noise is removed from the signal from the accelerometer.

Abstract: A method for forming sub-micron sized bumps on the bottom surface of a suspended microstructure or the top surface of the underlying layer in order to reduce contact area and sticking between the two layers without the need for sub-micron standard photolithography capabilities and the thus-formed microstructure. The process involves the deposition of latex spheres on the sacrificial layer which will later temporarily support the microstructure, shrinking the spheres, depositing aluminum over the spheres, dissolving the spheres to leave openings in the metal layer, etching the sacrificial layer through the openings, removing the remaining metal and depositing the microstructure material over the now textured top surface of the sacrificial layer.

Abstract: Method and apparatus are described for obtaining information about the real and imaginary parts of permittivity in dielectric materials and relating this information to other properties of the materials.

Abstract: An electrostatically actuated color video display is disclosed which can be illuminated by backlighting transmitted through the display and by reflected ambient light to have good visibility in both bright daylight and in subdued or dim light. To display full-color dynamically changing images from an electronic video signal the functions of creating the image and of generating color light rays for use in the image are separated. A preferred embodiment employs a pixellated color screen having rectangular cells of alternate red, green, blue and a somewhat opaque white color and a shuttering mask comprising an array of selectively actuatable light-modulating capacitors with black movable electrodes that when retracted are in registration with and present an open light path to individual color screen cells and when extended present a continuous black screen appearance.

Abstract: A variable capacitor for a high frequency circuit of an electrical appliance includes a chip capacitor mounted on a multilayer circuit board and interdigital capacitors formed at inner layers of the circuit board. A wiring pattern for soldering the chip capacitor is connected with the interdigital capacitors via through holes formed in the circuit board. Capacitance select portions are cut so that the capacitance best-suited to the circuit is obtained. The through holes connected to the interdigital capacitors of the inner layer are selectively disconnected from the wiring pattern for soldering the chip capacitor, thereby obtaining a variable capacitor capable of absorbing fluctuations of the circuit for selecting the best-suited capacitance.

Abstract: A capacitive position sensor employs conventional printed circuit board (PCB) technology to detect capacitive changes caused by the movement of a ball along conductive tracks. A recessed region (or through hole) is stamped on the PCB with well controlled dimensions. Electrically conductive tracks are laid around the region and connect to a capacitance detection circuit on the PCB. As the PCB experiences inclination or acceleration the ball moves along the axis of the recessed region causing variations in the measured capacitance.

Abstract: A capacitive biofeedback sensor including a polyurethane dielectric sandwiched between two wire mesh or carbon impregnated silicone rubber conductors. The sensor is placed within a patient's shoe, boot, ankle, brace, crutch, hand grip, wheelchair, etc., and provides biofeedback to help patients relearn function or prevent complications that impede function.

Abstract: An electrically controllable variable capacitor includes the interelectrode capacitance of at least one power MOSFET, a capacitance connected in series with the MOSFET and having one terminal connected to the drain or source thereof (the series capacitance), and bias control circuitry for controlling the bias voltage applied to the MOSFET. The voltage rating of the MOSFET, the peak amplitude of the applied ac signal, and the value of the series capacitance determine the range of dc bias voltages over which the MOSFET can be operated, and hence the capacitance range of the variable capacitor. Such a variable capacitance is useful as a tuning capacitor in an electrodeless HID lamp ballast.

Abstract: A compact capacitance type acceleration sensor in which a mass portion having a plurality of movable electrodes are arranged in a recess portion formed on the surface of a p-type single crystal silicon base plate under the condition that the mass portion can be displaced. A plurality of stationary electrodes are arranged at a position opposed to the movable electrodes being separate from the movable electrodes. The mass portion is elastically supported by a support from the lower side and also elastically supported by four beams from the lateral side. Due to the above structure, the damping characteristic of the mass portion can be improved.

Abstract: An electrostatically actuated micromechanical sensor having a guard band electrode for reducing the effect of transients associated with a dielectric substrate of the sensor. A proof mass, responsive to an input, is suspended over the substrate and one or more electrodes are disposed on the substrate in electrostatic communication with the proof mass to sense the input acceleration and/or to torque the proof mass back to a null position. A guard band electrode is disposed over the dielectric substrate in overlapping relationship with the electrodes and maintains the surface of the substrate at a reference potential, thereby shielding the proof mass from transients and enhancing the accuracy of the sensor.

Abstract: A contacting of a capacitive accelerometer sensor of monocrystalline material is achieved by a capacitive accelerometer sensor having a structure etched out of a monocrystalline layer arranged on a substrate, including a seismic mass that is only joined to the substrate by suspension segments and executing a movement in its longitudinal direction in response to the occurrence of an acceleration of parallel, plate-like first fingers extending out from this mass at right angles to their longitudinal direction and of plate-like second fingers running parallel to the first fingers and anchored to the substrate. The first and second fingers form a capacitor arrangement. The suspension segments, which are anchored with their end region that is distant from the seismic mass to the substrate, and second fingers are electrically isolated, by an isolation strip, from the other remaining layer of monocrystalline material.

Abstract: A capacitance change switch with a resiliently deformable conductive pad compressible against a dielectric coating on the surface of a pair of spaced coplanar thin foil plates formed on a refractory substrate. The pad forms with the plates a pair of capacitors electrically in series. User movement of an actuator causes pad compression and a significant electrically detectible change in capacitance for effecting a switching function. In one embodiment the pad is formed of conductive elastomer and in another embodiment the pad is formed of non-conductive elastomer with a conductive foil covering.

Abstract: An acceleration sensor is shown having a substrate (16, 16', 16", 16'") on which a capacitor detect plate (24) and source plate mounting portion (28c) are disposed. An electrically conductive blade member (40, 44) having an attachment portion (40a, 44h), a source plate portion (40i, 44a) and integrally attached beams (40b, 40c; 44b) extending along opposite sides of the blade member is mounted on the substrate by welding the attachment portion to a mounting element (36, 36', 36", 36'") which is closely received in a bore (32, 32', 32", 32'") formed through the substrate at the source plate mounting portion. The mounting element or the bore is formed with a surface suitable for forming an interference fit and for making electrical engagement with a conductive layer received in the bore. The mounting element has one end (36b, 36b', 36b") which extends above the top surface (26, 26") an adjustable selected amount(s) to provide desired spacing between the source plate portion and the detect plate.

Abstract: Angle and angular acceleration sensors are fabricated as a layered sandwich structure having a central sensing plate, left and right insulating spacers positioned outside the sensing plate, left and right driver plates positioned outside the insulating spacers, and left and right molded plastic housing shells positioned outside the driver plates for sealing the sensor structure. In an angle sensor embodiment of the invention, the sensing plate includes a peripheral frame and a central plate area mechanically connected to one side of the peripheral frame by way of a pair of beams that serve as a hinge to allow the central plate area of the sensing plate to rotate toward and away from the driver plates sandwiched on either side thereof.

Abstract: An acceleration sensor (10, 10', 10") in which a metal blade member (24) having a source plate portion (24a), attachment portion (24p) and integral resilient beams (24b) extending between the source plate portion and the attachment portion is attached to a pin (22) received in turn in a bore (18a) of a substrate (18). The metal blade member (24) is mounted on the substrate (18) so that the source plate portion is a selected distance from a detect plate (18b) mounted on the substrate. The sensor is disposed in a cylindrical housing (12, 12', 12") which can be directly mounted to a circuit board (50) through terminal pins (18g, 18h, 18i) or can be provided with a threaded fastener (12"d). In one embodiment first and second sensor modules are received in a housing (42) to sense acceleration forces in two perpendicular directions.

Abstract: A silicon capacitive microsensor which is sensitive to acceleration forces includes a silicon capacitive sensing element 10 comprising three silicon layers 12,16,26 having glass dielectric layers 14,24 between each pair of silicon layers with the middle silicon layer 16 consisting of a proof mass 18 suspended between the two glass dielectric layers 14,24 by a silicon hinge 20 which is connected to a slightly thicker silicon support layer 17 around the periphery (FIG. 3 ) between the glass layers 14,24 (FIG. 1 ). Three metallic bond pads 40,42,44 on the surface 45 of the silicon layers 26,16,12, respectively, are soldered to circuit trace pads 108 on a circuit board 100 which has a glass upper layer 104 and a silicon support layer 102. The thermal expansion coefficient between the glass layer 104 and the sensing element 10 are substantially the same, thereby minimizing thermally induced stresses on the sensing element 10 and minimizing inaccuracies associated therewith.

Abstract: Inventive electromagnetic-wave-modulating capacitors with movable electrodes are low-cost, low-energy, reliable and fast-acting elements for employment in highly transparent, conductive fixed electrodes and are incorporated, among others, in reflective display pixels for large and small-scale video displays, including full-color displays where multiple such capacitors are aligned in a single pixel. Further embodiments, not necessarily with a transparent electrode, are assemblable into array antennas deployable in outer space; provide digitally controllable or responsive such variable capacitors; and in mechanically active applications can be constituted as accelerometers, or in microrobotics. Constructions with ultra-thin electrodes have special advantages.

Abstract: A solid-state fringe effect capacitive proximity sensor is described which lends itself to use for surface mounting and other space constrained applications. The sensor comprises an insulating substrate having a plurality of sensing electrodes formed thereon and without any screen elements therebetween. The electrodes are adapted to measure the proximity distance of a target object (conductive or non-conductive) by means of the fringe capacitance effect created between the electrodes. Capacitance measurement processing circuitry is electrically connected to the plurality of sensory electrodes.

Abstract: A piezoelectric force sensor includes a piezoelectric plate, with one electrode on each of the top and bottom sides of the plate. One of the electrodes is electrically connected via a conductor to a contact pad. In the case that the piezoelectric plate experiences breakage, the conductor is broken, and the remaining residual capacitance of the conductor and contact pad becomes so comparatively small that the breakage can be reliably detected.

Abstract: Electrical impedance detector for measurement of physical quantities, in particular of temperature. The detector comprises electrodes (11,14), between which the electrical impedance (C;R) that represents the physical quantity to be measured is measured. Between these electrodes (11,14) there is an active material whose impedance properties are a function of the physical quantity to be measured. The active material of the detector is a very thin thread-like glass or glass-ceramic fibre (10), which has been manufactured by means of the glass-drawing technique. Further, a process for the manufacture of said detectors is described.

Abstract: A device forming a touch screen of the capacitive type intended in particular to cower a visualizing screen of a visualizing display unit such as a cathode ray tube. A group of electrically conducting transparent electrodes are arranged to be insulated from each other, not exposed to the outside and are connected to an electronic circuit for detecting capacitive variation. A second group of electrically conducting transparent electrodes insulated from each other are arranged to form front keys and are separated from the first group by a transparent dielectric material. The electrodes of the second group have substantially the same dimensions as the electrodes of the first group and are superimposed respectively upon the electrodes of the first group while facing one another so as to form pairs of capacitors. The effective capacity of each pair of capacitors varies when a body forming a mass reference frame is applied upon a front key.

Abstract: A capactive sensor contains a bridge circuit (1,2,3,4) which is comprised of an electrode surface (21) and a reference electrode surface (24) with the electrode surfaces located on the opposite sides of a plate. The bridge circuit is constructed as a multi-layered printed circuit board. The feed areas (23) which are opposite the electrode areas (21, 24) on one or two inner layers serve as feed capacitors (1, 2) in the bridge circuit (1, 2, 3, 4).

Abstract: An iron comprises a heating element (97), heating-control (96) for the heating element (97), and a motion detector. The motion detector can be an electrostatic detector (35) which determines an amount of electrostatic charges present at the fabric. The motion detector can be a humidity detector (60) which detects a resistivity of the fabric between two electrodes (62.sub.a, 62.sub.b) which are in contact with the fabric. A counting circuit (89) calculates a number of halfwaves of an electric signal supplied by one of the detectors and determines whether the iron is in use or is not in use. Moreover, the degree of humidity of the fabric can be determined by a measurement circuit (99).

Abstract: An acceleration sensor comprises an upper semiconductor substrate having a rigid frame, four deformable beams connected with the rigid frame, and a weight portion supported by the plurality of deformable beams, a lower semiconductor substrate bonded to the rigid frame, a plurality of movable electrodes attached to the weight portion, and electrically isolated from one another, and a plurality of stationary electrodes attached to the second semiconductor substrate, and opposite to the plurality of movable electrodes for forming a plurality of variable capacitors, and the center of gravity of the weight portion is spaced from a common neutral surface of the four beams for allowing acceleration to produce bending moment exerted on the four beams, thereby causing the variable capacitors to independently change the capacitance.

Abstract: A capacitive micro-sensor includes a sandwich of three silicon wafers, a peripheral stripe of each surface of the central plate being assembled to a corresponding stripe of an opposing external plate through an insulating layer. At least one of the external plates forms a first electrode, the central plate forms a second electrode and at least one portion of the central plate forms a variable capacity with at least one of the external layers. At least one of the insulating layers is formed by a sandwich of a first insulating layer, a conductive layer and a second insulating layer, the conductive layer being associated with connection means.

Abstract: Apparatus for measuring the distance between a surface of a workpiece and a predetermined location of the type which measures the capacitance between the predetermined location and the workpiece surface and determines the distance corresponding to the measured capacitance. The apparatus includes a probe disposed at said predetermined location, the probe may be selectively excited to a known electric potential. A support assembly for supporting the workpiece is mounted on the apparatus for rotation relative to the probe. The support assembly is constructed to support the workpiece for rotation and to maintain the workpiece at a substantially constant electric potential. A grounding mechanism for grounding the support assembly includes a fixed grounding member and a liquid ground contact which engages the support assembly for maintaining electrical contact between the support assembly and the fixed grounding member as the support assembly rotates relative to the fixed grounding member.

Abstract: An electrostatic type micro accelerometer comprising means for preventing permanent sticking between a movable electrode and a stationary electrode due to residual dielectric polarization, resisual electric charges and water adsorption and condensation around possible contacting portions therebetween when the movable electrode excessively displaces. The sticking preventing means is realized by disposing one of electric field reducing means, water adsorption and condensation reducing means and contacting area limiting means around the possible contacting portions.