Abstract:
A mobile system includes a self-supporting platform, a tunable reflective skin or film disposed on and secured to the mobile platform, one or more actuators and a controller. The tunable reflective skin or film includes one or more layers that are at least partially reflective to optical energy at one or more optical wavelengths. The skin or film is substantially flexible and/or stretchable and has an optical reflectivity to incident electromagnetic radiation of a given wavelength which is selectively variable when flexed and/or stretched. The actuators are able to flex and/or stretch the skin or film in response to receipt of a control signal. The controller generates the control signal based on a measured value of the optical reflectivity of the skin or film to the incident electromagnetic radiation of the given wavelength.
Abstract:
A hydro-thermal exchange unit (HTEU) for desalinating feed water in accordance with a humidification-dehumidification includes feed water, fresh water and gas conduit circuits for transporting feed water, fresh water, and gas, respectively. The unit also includes an evaporator through which a portion of the feed water conduit and the gas conduit pass. The evaporator causes evaporation of a portion of the feed water to produce vapor that is transported through the gas conduit. The unit also includes a condenser through which a portion of the gas conduit and the fresh water conduit pass. The condenser has input and output ports for coupling the gas and fresh water conduit circuits. The condenser extracts moisture from the vapor transported therethrough by the gas conduit. The extracted moisture is discharged through the fresh water conduit. The unit also includes a heat exchanger through which a portion of the fresh water conduit and the feed water conduit pass to thereby extract residual heat from the fresh water such that the residual heat heats the feed water.
Abstract:
A method and apparatus of forming compositionally homogeneous particles is provided. The method includes forming a homogenous melt from a plurality of constituent materials under a first pressure sufficient to prevent substantial vaporization of the constituent materials. Droplets are generated from the homogenous melt. The droplets are cooled under a second pressure sufficient to prevent substantial vaporization of the constituent materials at least until the homogeneous particles formed therefrom have stabilized.
Abstract:
A multi-functional, multi-layer film or skin which may be used as a covering for a structure or platform incorporates an integrated photovoltaic element and an integrated RF antenna element. The film or skin is suitable for use in various applications, including those involving autonomous, self-powered, mobile communication systems and especially for use as a skin or covering for solar powered aircraft and UAVs. Planar PV cells and planar RF antenna are used to facilitate their integration into the film or skin. The PV cells and RF antenna are configured to face operate outward from opposite faces of the skin. The film or skin addresses potential problems arising from conflicting directional requirements for PV orientation and antenna pointing on mobile platforms. This is accomplished by employing wide angle AR coatings on the PV elements and electrical controls to steer the RF antenna.
Abstract:
A photovoltaic device is provided which includes a plurality of junction layers. Each junction layer includes a plurality of photovoltaic cells electrically connected to one another. At least one of the junction layers is at least in part optically transmissive. The junction layers are arranged in a stack on top of each other.
Abstract:
A multi-input electrical power conversion device is provided for converting multiple DC energies each arising from different junctions in a multi-junction solar cells into AC energy. The device includes a plurality of electrical inputs for receiving the multiple DC energies from at least one multi-junction solar cell. The number of DC energies id no less than the number of junctions in the multi-junction solar cell. The device also includes at least one DC-to-AC circuit for receiving the multiple DC energies from the plurality of electrical inputs and at least one electrical output receiving at least one AC energy from the DC to AC circuit. The device also includes at least one MPPT circuit operatively coupled to the DC to AC circuit.
Abstract:
A method is provided for fabricating a thin film semiconductor device. The method includes providing a plurality of raw semiconductor materials. The raw semiconductor materials undergo a pre-reacting process to form a homogeneous compound semiconductor target material. The compound semiconductor target material is deposited onto a substrate to form a thin film having a composition substantially the same as a composition of the compound semiconductor target material.
Abstract:
An electro-optic device includes at least one electro-optic module having first and second conductive layers and at least first and second semiconductor layers disposed between the conductive layers. At least one optically transparent, electrically insulating base substrate is disposed on the module. The base substrate has a plurality of grooves disposed therein and an electrically conducting material filling the grooves. Electrical contact is established between the conducting material and at least one of the conducting layers of the module.
Abstract:
Free-standing, flexible articles (skins), with settable or tunable reflectivity, for a defined range of electromagnetic frequencies are provided. The articles include a monolayer, or multi-layers, of ductile or elastic materials which retain mechanical integrity when the skin is stretched, flexed or otherwise altered in shape during deployment or use. The articles may further include an optical structure which exhibit changeable reflectivity when the skin is stretched, flexed or otherwise altered in shape. Methods of tuning the reflective characteristics of such skin through stretching, flexing or otherwise changing shape are also provided.
Abstract:
A method is provided for producing a thin-film photovoltaic device. The method includes forming on a substrate a first thin-film absorber layer using a first deposition process. A second thin-film absorber layer is formed on the first thin-film absorber layer using a second deposition process different from the first deposition process. The first and second thin-film absorber layers are each photovoltaically active regions and the second thin-film absorber layer has a smaller concentration of defects than the first thin-film absorber layer.