Abstract:
A thermal isolation structure for use in passively regulating the temperature of a microdevice is disclosed. The thermal isolation structure can include a substrate wafer and a cap wafer defining an interior cavity, and a number of double-ended or single-ended thermal bimorphs coupled to the substrate wafer and thermally actustable between an initial position and a deformed position. The thermal bimorphs can be configured to deform and make contact with the cap wafer at different temperatures, creating various thermal shorts depending on the temperature of the substrate wafer. When attached to a microdevice such as a MEMS device, the thermal isolation structure can be configured to maintain the attached device at a constant temperature or within a particular temperature range.
Abstract:
A technique for manufacturing a piezoresistive sensing structure (170) includes a number of process steps. Initially, a piezoresistive element (108) is implanted into a first side of an assembly (102,106,104A) that includes a semiconductor material (102,104A). A passivation layer (110A) is then formed on the first side of the assembly (102,106,104A) over the element (108). The passivation layer (110A) is then removed from selected areas on the first side of the assembly (102,106,104A). A first mask is then provided on the passivation layer (110A) in a desired pattern. A beam (152), which includes the element (108), is then formed in the assembly over at least a portion of the assembly (102,106,104A) that is to provide a cavity (103). The passivation layer (110A) provides a second mask, in the formation of the beam (152), that determines a width of the formed beam (152).
Abstract:
An epitaxial layer (3, 5) is deposited on a substrate (1) with adjacently grown mono- and poly-crystalline silicon. A region (5, 6) is exposed as a vertically displaceable polycrystalline membrane, in particular for a pressure sensor, by means of etching. The poly/mono transition regions to both sides of the membrane each have an inclined profile such that the mono-crystalline silicon extends over the polycrystalline silicon in the form of a overhang (6) in the membrane region (5, 6). Piezoelements (10) are implanted in the overhang (6).
Abstract:
A MEMS (Micro Electro Mechanical System) electrostatic device operated with lower and more predictable operating voltages is provided. An electrostatic actuator, an electrostatic attenuator of electromagnetic radiation, and a method for attenuating electromagnetic radiation are provided. Improved operating voltage characteristics are achieved by defining a non increasing air gap between the substrate electrode and flexible composite electrode within the electrostatic device. A medial portion of a multilayer flexible composite overlying the electromechanical substrate is held in position regardless of the application of electrostatic force, thereby sustaining the defined air gap. The air gap is relatively constant in separation from the underlying microelectronic surface when the medial portion is cantilevered in one embodiment. A further embodiment provides an air gap that decreases to zero when the medial portion approaches and contacts the underlying microelectronic surface. A moveable distal portion of the flexible composite is biased to curl naturally due to differences in thermal coefficients of expansion between the component layers. In response to electrostatic forces, the distal portion moves and thereby alters the distance separating the flexible composite from the underlaying microelectronic surface. Structures and techniques for controlling bias in the medial portion and the resulting air gap are provided. The electrostatic device may be disposed to selectively clear or intercept the path of electromagnetic radiation. Materials used in the attenuator can be selected to pass, reflect, or absorb various types of electromagnetic radiation. A plurality of electromagnetic attenuators may be disposed in an array and selectively activated in subsets.
Abstract:
A micromechanical system can include a substrate, an actuator, and an actuated element. In particular, the actuator can include a serpentine arrangement of alternating actuating and opposing segments anchored at a first end thereof to the substrate wherein the actuating segments deflect in response to actuation thereof so that a second end of the serpentine arrangement moves relative to the substrate upon deflection of the actuating segments. The actuated element is attached to the second end of the serpentine arrangement so that the actuated element moves relative to the substrate upon deflection of the actuating segments. Related methods and actuators are also discussed.
Abstract:
In a MEMS device employing a beam supported by transverse arms, potential bowing of the transverse arms caused by fabrication processes, temperature or local self-heating from resistive losses is accommodated by flexible terminations of the transverse arms. Alternatively, this bowing is controlled so as to provide selective biasing to the beam or mechanical advantage in the sensing of beam motion.
Abstract:
A MEMS device, and method of fabrication thereof, comprising: a wall arranged as a closed loop(for example, comprising a plurality of interconnected lengths (11-18)); and a bridging portion (54) having two ends and an intermediate portion between these ends; the bridging portion (54) is connected at one end to a first portion of the wall and at the other end to a second portion of the wall non-contiguous to the first; whereby when the intermediate portion is displaced in a direction through a plane defined between the two ends, the portions of the wall connected to the bridging portion (54) are each displaced in a respective direction in the plane, and at least one further portion of the wall is displaced in a direction that is in the plane and that is different to the directions that the two portions connected to the bridging portion (54) are displaced in.
Abstract:
Provided is a polymer actuator element that can maintain satisfactory durability and has a great displacement amount or a great generating force, and excellent responsiveness. A polymer actuator element 1 includes an electrolyte layer 2 and electrode layers 3 and 4, in which the electrode layers 3 and 4 include an activated carbon nanofiber and a carbon nanohorn.