Abstract:
An optical detection apparatus includes a housing having a circumferential opening therein. A primary mirror reflects light rays to form a first set of light rays to a secondary mirror that has a generally concave shape coupled to the housing. A tertiary mirror having a generally concave shape coupled to the housing spaced apart from the secondary mirror directs light to detection optics that form an image using the third set of light rays. The detection optics include a micro-mirror array that redirect the image to a detector. A controller controls the micro-mirror array and determines an event characteristic based upon the image thereon.
Abstract:
A piezoelectric device connected to a vibration source converts vibration energy to electrical current. A plurality of pairs of oppositely polarized piezoelectric wafers deflect to produce an electrical current. Each pair of wafers are arranged back-to-back and electrically joined together. The plurality of pairs of wafers are each connected to a set of micro-machined parts. Each pair of wafers form a bimorph, configured as a cantilevered beam attached to a set of parts to form an element. Each cantilevered beam has a mass weighted first end and is fixedly attached to one or more flexible sheaths on a second end. A plurality of elements form a cell unit. A plurality of cell units form an array. The electrical current produced varies by the number of elements per cell unit, and/or with the number of cell units per array.
Abstract:
A metamaterial has a magnetic permeability response at frequencies sufficient to generate a repulsive force between a fluid and a surface to which the metamaterial may be applied. The metamaterial may be nanofabricated such that an absolute value of the magnetic permeability of the metamaterial is substantially greater than an absolute value of an electric permittivity of the metamaterial. The metamaterial may generate a repulsive force between the surface and the fluid moving relative to the surface and thereby reduce viscous drag of the fluid on the surface. A method of reducing the viscous drag of the fluid moving past the surface includes producing relative motion between the surface and the fluid and generating the repulsive force between the surface and the fluid.
Abstract:
A method for fabricating an acoustic metamaterial may include providing a planar pattern of springs arranged in columns and rows and separated from each other by interconnection nodes, providing a planar pattern of mass units separated from each other by a distance corresponding to a distance between the interconnection nodes, providing an array of vertically oriented springs separated from each other by the distance between the interconnection nodes, and aligning and joining the planar pattern of springs, the planar pattern of mass units and the array of vertically oriented springs to form a layer of unit cells.
Abstract:
A leaky cavity resonator that includes a waveguide, the waveguide being filled with a dielectric material, and at least two complementary split ring resonators (CSRRs), the CSRRs residing inside the waveguide parallel to each other placed symmetrically both radially and in height, a leaky resonant cavity being formed between the at least two CSRRs and a wall of the waveguide. A frequency band of the leaky cavity resonator is adjustable by varying a distance w between at least one outside perimeter of at least one CSRR and an interior wall of the waveguide. A frequency band of the leaky cavity resonator is also adjustable by varying a size of the leaky resonant cavity. The at least two CSRRs each have at least one stub connecting to a wall of the waveguide. A frequency band of the leaky cavity resonator is also adjustable by varying a size of the stubs.
Abstract:
Methods and apparatus for improved thermal isolation for thermoelectric devices are disclosed. In one embodiment, a thermoelectric device includes a first substrate having a first conductive pad, a second substrate having a second conductive pad, and a gap formed between the first and second conductive pads. At least one of the first and second substrates includes at least one opening positioned adjacent to an outer peripheral edge of the conductive pad. The opening may comprise a trench disposed partially or entirely around the outer peripheral edge of the conductive pad. In operation, the opening inhibits heat transfer between the first and second substrates.
Abstract:
A method is provided to generate electrical current. The method includes creating a plurality of unitary masses each connected to one of a plurality of piezoceramic mass supports. The mass supports are electrically joined to a sheath. The method also includes removing material from the unitary masses to operably limit a mass vibration deflection. The sheath is attached to a vibrating body. The unitary masses are pre-tuned to match at least one natural frequency mode of the vibrating body. The unitary masses and the piezoceramic mass supports are induced to vibrate to generate the electrical current.
Abstract:
Semiconductor materials optimized for their electrical conductivity and thermal conductivity promise much higher thermoelectric cooling power. The materials can achieve the same cooling or power generation capacity in thermopiles with less electron current compared with present bulk materials. Because less electron current is required to accomplish the same task, total thermopile semiconductor material cross-sectional area normal to thermal and electron flow is greatly reduced and the element length-to-cross-sectional area aspect ratio is increased. The net result is a significant improvement in the figure of merit, ZT, and in the device Coefficient of Performance (COP).
Abstract:
Silicon wafers containing conductive feedthroughs of an hourglass shape located around their peripheries that can be incorporated into multichip modules that includes silicon wafer spacers having radial grooves for receiving cooling fluid.
Abstract:
A method for producing a planar surface on which conductive traces can be formed to fabricate a multi-layer integrated circuit. In this method, a substrate (20) serves as a base for the formation of conductive traces including copper conductors (30). These conductors are preferably bonded to an adhesion layer (22) and coated with a corrosion barrier (31). A first polyimide coating (34) is spin coated over the substrate and the copper conductors, leaving an undulating surface. Portions of the first polyimide coating lying above the copper conductors are removed, and the resulting surface is coated with a second polyimide coating (44). The polyimide comprising the first and second coatings is selected for its characteristic ability to partially dissolve a previously applied layer of the material, so that the two layers combine, thereby leveling out an non-planar irregularities existing in the first layer. The resulting planar surface forms a base for application of subsequently applied copper conductors (54), which are connected to the previously applied copper conductors at vias, photolithographically formed in the second polyimide coating. Additional layers of copper conductors can be applied to the planar surface as the process is repeated.