Abstract:
A fluid property sensor includes a substrate having a first electrode thereon, and a flexible member adjacent the substrate and the first electrode wherein the flexible member includes a second electrode. A signal generator generates a predetermined electrical signal across the first and second electrodes so that an electrostatic force is generated between the first and second electrodes and so that said flexible member deflects a predetermined distance. A measuring circuit measures an interval of time between the generation of the predetermined electrical signal and the deflection of the flexible member to the predetermined distance and determines a property of a fluid adjacent the flexible member based on the interval of time. For example, the sensor can be used to determine a viscosity of the fluid. Alternately, the fluid can be a compressible gas, and the sensor can be used to determine a pressure of the gas. Related methods are also discussed.
Abstract:
Optical apparatus for forming correlation spectrometers and optical processors. The optical apparatus comprises one or more diffractive optical elements formed on a substrate for receiving light from a source and processing the incident light. The optical apparatus includes an addressing element for alternately addressing each diffractive optical element thereof to produce for one unit of time a first correlation with the incident light, and to produce for a different unit of time a second correlation with the incident light that is different from the first correlation. In preferred embodiments of the invention, the optical apparatus is in the form of a correlation spectrometer; and in other embodiments, the apparatus is in the form of an optical processor. In some embodiments, the optical apparatus comprises a plurality of diffractive optical elements on a common substrate for forming first and second gratings that alternately intercept the incident light for different units of time. In other embodiments, the optical apparatus includes an electrically-programmable diffraction grating that may be alternately switched between a plurality of grating states thereof for processing the incident light. The optical apparatus may be formed, at least in part, by a micromachining process.
Abstract:
A method for polishing a substrate having at least one micro-sized structure. The method includes identifying a first region of the substrate on which a micro-sized structure is to be located. The first region is the region in which polishing is desired. A second region of the substrate, in which polishing is not desired, is also identified. An adhesion promoter is optionally applied to the substrate. The second region of the substrate is coated with a selected coating material that does not degrade substantially when exposed to a selected electrolyte. Material is removed from the first region, exposing a micro-sized structure. The coating material may be removed by the same machining process that forms the micro-sized structure. The substrate is submerged in the selected electrolyte so that the first region is exposed to the electrolyte. The first region of the substrate is electropolished. The coating is then optionally removed.
Abstract:
An electrostatic micromotor employs a side drive design. The stator operates in a plane above a substract and a moveable member lies and moves in the plane of the stator. An electrostatic field of operational strength is generated and sustained without breakdown in the plane between the stator and edges of the moveable member. Three fabrication processes enable formation of a moveable member in the plane of operation of the stator and spaced apart from the stator by a micron amount. One fabrication process deposits and patterns a structural layer to form the stator and moveable member over a sacrificial layer. A second fabrication process etches channels in a first structural layer to outline a stator, moveable member, and if desired, a bearing. A substrate is connected to the side of the structural layer through which the channels are etched and the opposite side is ground down to the ends of the channels to form salient stator, rotor and, if desired, bearing structures. The third fabrication process grows a sacrificial layer by local oxidation in an etched cavity of the substrate. A structural layer is then deposited and patterned over the substrate and sacrificial layer to form the stator and moveable member in a common plane. A harmonic side drive micromotor is also provided by the fabrication processes.
Abstract:
An electrostatically driven microactuator is micromachined in a monolithic process. Sacrificial layers are placed between a moving element and stator structural layers. Removal of the sacrificial layers leaves a free standing moving element and micron wide air gaps within a stator. An electric field of about 100 Mv/m and higher is supported across the micron wide gap without breakdown and enables high energy torque densities to be produced between the stator and the moving element. One electrostatic drive scheme involves a series of stator electrodes attached to the stator and a series of electrodes attached to the moving element charged in sequence to attract each other in a direction of movement and to oppose each other in a direction normal to movement. A bearing is aligned with the moving element within the stator during the layering of a sacrificial layer over an edge of the moving element structural layer. The bearing and stator laterally stabilize the moving element. Vertical stability is through aerodynamic shaping of the moving element, electronic circuits, or bushings. Applications of the microactuator include a linearly sliding shutter, an optical modulator, a gyroscope and an air pump.
Abstract:
A multi-layer interconnect structure of alternating dielectric (e.g., polyimide) and metal (e.g., copper) is built on a substrate supporting a continuous layer of metal. This metal layer is used as an electrode for plating vias through all the dielectric layers. Once the desired number of layers are formed, the substrate is removed and the continuous metal layer is patterned. Solid metal vias having nearly vertical side walls can be stacked vertically, producing good electrical and thermal transfer paths and permitting small, closely-spaced conductors. Further, by mixing geometrical shapes of conductors, a variety of useful structures can be achieved, such as controlled impedance transmission lines and multiconductor TAB tape with interconnects on tape of different dimensions than TAB fingers.
Abstract:
A method for determining the moisture content of dielectric materials is described wherein a sample of the material is placed between two electrodes and an electric field is applied. An alternating frequency in the range of radio waves and lower is applied to the electrodes and the dielectric loss properties of the material are determined. The dielectric loss properties are then used to determine moisture content. In an alternate embodiment, a step voltage is applied to the electrodes and the direct current is monitored. The decrease in value of direct current during a time interval following the application of the step voltage is used to determine the moisture content.
Abstract:
A waveguide-based sensor is disclosed that uses one or more grating patterns of a bioreceptor on a surface of the waveguide to provide a wavelength-specific sensor response without the requirement of labeling the target molecule or the bioreceptor. Furthermore, there is provided a biosensor that, at least to a first order, is insensitive to non-specific binding.
Abstract:
A method of redirecting light using an actuatable two-layer diffraction grating structure, the method having applications in wavelength-division multiplexed systems. An optical add/drop modulator (OADM) including an actuatable diffraction grating, for use with a wavelength-division multiplexed signal. An OADM having an optical source located off the main pathway to direct a optical carrier to be added onto the actuatable diffraction grating such that the carrier is diffracted into the main pathway. A detector to measure signal strength for use with an optical processor, the optical processor having an actuatable structure having gaps between the actuated portion of the structure. The detector detecting the portions of light diffracted by the gaps.
Abstract:
The invention provides an electrostatically-controllable diffraction grating including a plurality of electrically isolated and stationary electrodes disposed on a substrate. At least one row of a plurality of interconnected actuation elements is provided, with each actuation element suspended, by a corresponding mechanically constrained support region, over the substrate by a vertical actuation gap and including a conducting actuation region connected to the corresponding support region and disposed in a selected correspondence with at least one substrate electrode. A mirror element is provided, for at least one actuation element in at least one row of actuation elements, including an optically reflecting upper surface, and being vertically suspended over a corresponding actuation element by a mechanically constrained mirror support region that is connected to the corresponding actuation element and that defines a vertical mirror gap. A mirror deflection region connected to the mirror support region and is free to be deflected through the mirror gap. The mirror gap is less than the actuation gap of a corresponding actuation element and is selected to produce controlled and stable displacement of the actuation region of a corresponding actuation element through a displacement range to a specified point in the actuation gap when an actuation voltage is applied between an actuation region and a corresponding stationary electrode. This enables diffraction of a beam of light incident on the grating as the light beam is reflected from the upper surfaces of the mirror elements.