Abstract: By directly connecting, ballast to an emitter electrode of an ion generator (e.g., a corona-discharge device), a rapid and self-corrective reduction in emitter-to-collector voltage may be provided responsive to an increase in current characteristic of incipient sparking discharge. Voltage levels in the emitter-to-collector gap can be rapidly reduced based on voltage drop across the ballast that, while negligible under nominal ion current conditions, transiently increases in the event of a sparking discharge. As a result, the portion of supply voltage (typically multi-KV supply voltage) across the emitter-to-collector gap is transiently reduced to levels below a current breakdown voltage and, indeed, field intensity proximate to the emitter is transiently reduced below levels otherwise necessary to sustain ion generation.

Abstract: Cleaning and/or conditioning electrode surfaces can provide significant performance and operational benefits in EHD devices. In particular, conditioning of emitter electrode surfaces with silver (Ag), silver compositions or silver preparations applied in situ at successive times throughout the operating lifetime of an EHD air mover has been found to significantly reduce ozone production. Structures and techniques are described for in situ conditioning electrode surfaces and, in particular, emitter electrode surfaces of an EHD device such as an air mover or precipitator, with a conditioning material that includes silver.

Abstract: An electrohydrodynamic fluid accelerator apparatus includes a corona electrode having an axial shape and configured to receive a first voltage. The electrohydrodynamic fluid accelerator apparatus includes a collector electrode disposed coaxially around the at least one corona electrode and configured to receive a second voltage. Application of the first and second voltages on the corona electrode and the collector electrode, respectively, causes fluid proximate to the corona electrode to ionize and travel in a first direction between the corona electrode and the collector electrode, thereby causing other fluid molecules to travel in a second direction to generate a fluid stream. In at least one embodiment of the invention, the ionized fluid proximate to the emitter electrode travels in a radial direction from the corona electrode to the collector electrode, causing the other fluid molecules to travel in an axial direction to thereby generate the fluid stream.

Abstract: An electronic system is configurable to accommodate either of a mechanical air mover and an EHD air mover within an enclosure. At least one of a plurality of electronic components is selectively configurable to alternately accommodate the mechanical air mover or the EHD air mover within the enclosure. The mechanical fan or EHD is positioned to motivate air flow along a air flow path between inlet and outlet ventilation boundaries of the enclosure. A connector for a respective one of the electronic components allows for selective configuration in an alternate orientation of the respective one of the electronic components to accommodate a difference in geometry between the EHD air mover and the mechanical air mover.

Abstract: An apparatus for tandem cleaning of an emitter electrode and collector electrode in electrohydrodynamic fluid accelerator and precipitator devices via movement of a cleaning mechanism including respective cleaning surfaces positioned to frictionally engage the emitter electrode and collector electrode. The cleaning mechanism causes the respective cleaning surfaces to travel along a longitudinal extent of the emitter electrode and, in tandem, over a major dimension of the collector electrode to remove detrimental material from respective electrode surfaces. Alternatively, the electrodes can be transited in tandem in frictional engagement with a fixed cleaning mechanism in the same or opposite directions. A conditioning material is optionally deposited on an electrode to at least partially mitigate ozone, erosion, corrosion, oxidation, or dendrite formation on the electrodes. The conditioning material can include an ozone reducer.

Abstract: Cleaning and/or conditioning electrode surfaces can provide significant performance and operational benefits in EHD devices. In particular, conditioning of emitter electrode surfaces with silver (Ag), silver compositions or silver preparations applied in situ at successive times throughout the operating lifetime of an EHD air mover has been found to significantly reduce ozone production. Structures and techniques are described for in situ conditioning electrode surfaces and, in particular, emitter electrode surfaces of an EHD device such as an air mover or precipitator, with a conditioning material that includes silver.

Abstract: A tilting mirror MEMS variable optical attenuator attenuates light over a band of wavelengths with minimum wavelength dependent loss. The attenuator includes a lens that has a wedged input face and is made from a material that has high dispersion. The lens design causes different wavelengths to travel different paths through the attenuator such that wavelength dependent loss is reduced. The attenuator may be designed to have minimum wavelength dependent loss at a specified attenuation greater than zero.

Abstract: Flow paths, duct work, ventilation boundaries, and/or placement of EHD and mechanical air mover within a electronic device enclosure can all affect the efficacy of a thermal management solution that seeks to provide silent air cooling over a significant thermal operating envelope with staged introduction of electrohydrodynamic (EHD) and mechanical air mover devices. For electronic devices in which it is desirable to employ passive, unforced convective cooling over a portion of the thermal operating envelope, practical designs for consumer electronics form factors may be quite sensitive to flow path, duct work and ventilation boundary design as well as to the placement of EHD and mechanical air mover components relative thereto and to each other. A range of inventive solutions that have been developed to address some or all of these design challenges.

Abstract: Techniques are described for integration of EHD-type air movers with electronic systems, and in particular, for limiting infiltration of ions and/or charged particulates into an internal air plenum. In some designs, it may be desirable to allow or even encourage EHD motivated air flow (whether drawn or forced) through the internal air plenum while providing a barrier to transit of ions and/or charged particulates that may be generated during EHD operation. Such a barrier may employ electrostatic forces to impede transit of ions and/or charged particulate across a vent positioned to allow air flow from or into the internal air plenum. In some cases, an electrostatic barrier may include a fluid permeable mesh or grill that spans a substantial cross-section of the vent.

Abstract: An electronic system is configurable to accommodate either of a mechanical air mover and an EHD air mover within an enclosure. At least one of a plurality of electronic components is selectively configurable to alternately accommodate the mechanical air mover or the EHD air mover within the enclosure. The mechanical fan or EHD is positioned to motivate air flow along a air flow path between inlet and outlet ventilation boundaries of the enclosure. A connector for a respective one of the electronic components allows for selective configuration in an alternate orientation of the respective one of the electronic components to accommodate a difference in geometry between the EHD air mover and the mechanical air mover.

Abstract: An electronic system including an enclosure and an internal air plenum within the enclosure. At least one component of the electronic system within the enclosure evolves heat and has a surface exposed to the internal air plenum. The enclosure has inlet and outlet ventilation boundaries together with an EHD air mover disposed therein to motivate airflow along a flow path between the inlet and outlet ventilation boundaries, wherein the flow path is substantially excluded from the internal air plenum by a barrier.

Abstract: Electrostatic precipitation is performed upstream of collector electrode surfaces toward which a downstream EHD fluid mover accelerates fluid flow. In this way, the upstream electrostatic precipitator (ESP) acts as a pre-filter (with low flow-impedance) and can reduce accumulation of otherwise detrimental materials on downstream electrodes and/or arcing. In some cases, pre-filtering by an upstream electrostatic precipitator may also reduce accumulation of otherwise detrimental materials on downstream heat transfer surfaces and/or ozone catalytic or reactive surfaces/materials. In some embodiments, an EHD fluid mover with an ESP pre-filter is used in a thermal management system to dissipate heat generated by a thermal source.

Abstract: A thermal management apparatus includes an electrohydrodynamic fluid accelerator energizable to motivate fluid flow. Primary heat transfer surfaces are positioned to transfer heat into the fluid flow and an ozone reducing material is positioned downstream of the primary heat transfer surfaces. Heating of the ozone reducing material by the fluid flow increases the efficacy of the ozone reducing material. A method of making a product includes positioning an emitter electrode and at least one other electrode to motivate fluid flow along a flow path when the electrodes are energized. The method further includes positioning heat transfer surfaces in the flow path to transfer heat to the fluid flow and positioning ozone reducing material downstream of the heat transfer surfaces in the flow path, the ozone reducing material selected such that heating of the ozone reducing material by the fluid flow increases ozone reducing efficacy of the ozone reducing material.

Abstract: A tilting mirror MEMS variable optical attenuator attenuates light over a band of wavelengths with minimum wavelength dependent loss. The attenuator includes a lens that has a wedged input face and is made from a material that has high dispersion. The lens design causes different wavelengths to travel different paths through the attenuator such that wavelength dependent loss is reduced. The attenuator may be designed to have minimum wavelength dependent loss at a specified attenuation greater than zero.

Abstract: Multi-stage electrohydrodynamic (MHD) fluid flow acceleration is described. In some embodiments, an EHD fluid accelerator apparatus includes a substrate for thermal conduction and a plurality of electrode structures for thermal conduction therethrough, wherein each electrode structure has a collector electrode portion and a corona discharge electrode portion.

Abstract: An electrohydrodynamic fluid accelerator apparatus includes a corona electrode having an axial shape and configured to receive a first voltage. The electrohydrodynamic fluid accelerator apparatus includes a collector electrode disposed coaxially around the at least one corona electrode and configured to receive a second voltage. Application of the first and second voltages on the corona electrode and the collector electrode, respectively, causes fluid proximate to the corona electrode to ionize and travel in a first direction between the corona electrode and the collector electrode, thereby causing other fluid molecules to travel in a second direction to generate a fluid stream. In at least one embodiment of the invention, the ionized fluid proximate to the emitter electrode travels in a radial direction from the corona electrode to the collector electrode, causing the other fluid molecules to travel in an axial direction to thereby generate the fluid stream.

Abstract: A tilting mirror MEMS variable optical attenuator attenuates light over a band of wavelengths with minimum wavelength dependent loss. The attenuator includes a lens that has a wedged input face and is made from a material that has high dispersion. The lens design causes different wavelengths to travel different paths through the attenuator such that wavelength dependent loss is reduced. The attenuator may be designed to have minimum wavelength dependent loss at a specified attenuation greater than zero.

Abstract: A tilting mirror MEMS variable optical attenuator attenuates light over a band of wavelengths with minimum wavelength dependent loss. The attenuator includes a lens that has a wedged input face and is made from a material that has high dispersion. The lens design causes different wavelengths to travel different paths through the attenuator such that wavelength dependent loss is reduced. The attenuator may be designed to have minimum wavelength dependent loss at a specified attenuation greater than zero.

Abstract: A method is provided of forming a capped chip which includes a conductive interconnect exposed through an opening in the cap. A cap having openings extending between outer and inner surfaces is aligned and joined to a chip. A mass of fusible conductive material is positioned through a first such opening onto a first such bond pad of the chip. The positioned mass is heated to bond the mass to the first bond pad. The steps of positioning and heating the mass form at least a portion of a conductive interconnect extending from the first bond pad at least partially through the first opening.

Abstract: An electronic camera module includes a lens or refractive element formed by a pair of immiscible liquids and having optical properties which can be varied by applying a voltage so as to deform the meniscus. One of the two liquids extends from the meniscus all the way to the front surface of the sensor, so that light passing through the meniscus does not encounter further changes in refractive index enroute to the sensor.