Patent Application
20170058440
Radiofrequency (RF) systems, such as cell phones and geo-positioning systems (GPS) employ micro circuitry that includes wire connectors having diameters as small as a few nanometers. At the same time, energy storage and such systems is limited and, therefore, loss of energy, such as through electrical heat loss, are significant, thereby further limiting utility and ability to scale down the size of such devices.
One option for reducing electrical heat loss from wires is to braid or twist them, whenever possible, so that are in relatively close proximity to each other. However, wires on such a small scale are not only difficult to manufacture, but are extremely fragile and have a limited ability to bend. Further, the size of wires on a nano- and micrometer scale are difficult to manipulate, once fabricated, and are extremely susceptible to failure.
Therefore, a need exists for a method of assembling nano and micrometer-scale wires in a braid, weave or twist that overcomes or minimizes the above-referenced problems.
The invention generally is directed to a method of weaving a braided, woven or twisted wire, typically for use in RF systems, such as cell phones and GPS systems.
In one embodiment, the method of weaving a braided, woven or twisted wire includes attaching an end piece to a first end of each of a plurality of wires, each end piece having a response to an electromagnetic or fluidic force different than that of the wire. Respective second ends of each of the wires are fixed relative to each other, and the end pieces are manipulated relative to each other by selective application of an electromagnetic or fluidic force that braids or twists the wires to thereby weave the braided or twisted wire.
Typically the wire is a microwire, having a diameter in a range of between about 1 μm and about 1 mm. Alternatively, the wire is a nanowire, having a diameter in the range of between about 1 nm and about 100 nm.
The wire is formed of a suitable material, such as a material that includes at least one member of the group consisting of a metal, a ceramic, a polymer, and a glass.
The end piece typically includes at least one member of the group consisting of a dielectric material, a magnetic material, a metallic material, and a ferro-electric material. In one specific embodiment, the end piece is formed of a dielectric material that is an electret.
The end piece in one embodiment is a bead. Alternatively, the end piece can be a spool of the wire that is braided, woven or twisted by the method of the invention.
Examples of suitable electromagnetic forces that can be employed to manipulate the end pieces typically include at least one member of the group consisting of an electrostatic force, a magnetostatic force, an electroquasistatic force, and an optical electromagnetic field.
Examples of suitable fluidic forces that can be employed typically includes at least one member selected from the group consisting of pressure, a concentration gradient, a thermal gradient, and an electrogradient.
In one embodiment, the end pieces are selectively manipulated by use of an addressable platform that controls an electromagnetic force to which the end pieces are exposed. The beads or spools move relative to each other by responding to selective application of a force from, for example, an addressable platform, thereby braiding, weaving or twisting the wires to which the end pieces are attached.
This invention has many advantages. For example, by braiding, weaving or twisting the wires, electrical heat loss in the wires during use and or assistance is significantly reduced, thereby resulting in better performance and greater durability of electrical systems in which they are employed. In addition, braiding, weaving or twisting of the wires by the method of the invention can be done rapidly and at a very low rate of failure. Braiding, weaving, or twisting also provides high mechanical strength while preserving mechanical flexibility.
The foregoing will be apparent from the following more particular description of example embodiments of the invention, as illustrated in the accompanying drawings in which like reference characters refer to the same parts throughout the different views. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating embodiments of the present invention.
A description of example embodiments of the invention follows.
The invention generally is directed to a method of weaving a braided or twisted wire for the use in RF systems, such as cell phones and GPS systems.
“Braiding,” as that term is understood herein, means plaiting or interweaving a continuous length of material to form a braid.
“Weaving,” as that term is employed herein, means interlacing or entwining a continuous material, also referred to herein as a “wire.”
“Twisting” means interweaving or twining a continuous length of material, such as a wire to form a weave of that material.
In one embodiment, the method includes attaching an end piece to a first end of each of a plurality of wires. Examples of suitable wires include microwires and nanowires. In one embodiment, the wire is a microwire, having a diameter in a range of between about 1 μm and about 1 mm. In another embodiment, the wire is a nanowire, having a diameter in a range of between about 1 nm and about 100 nm.
The wires suitable for use in the method of the invention are those typically employed in the fabrication of RF devices or other devices that employ microcircuitry and nanocircuitry. Examples of suitable wires include those that are formed of at least one member of the group consisting of a metal, a ceramic, a polymer, and a glass. Examples of suitable metals include copper, silver and gold. Example of a suitable ceramics is aluminum oxide. An example of a suitable polymer is polyimide. Examples of suitable glasses include silicon dioxide. Examples of suitable nanotubes include those formed of at least one material selected from the group consisting of carbon and inorganic material.
In one embodiment, the wire has a dielectric core, coated by an electrically conductive layer which, in turn, is insulated from its surrounding environment by the dielectric coating.
The end pieces are formed of a suitable material that is susceptible to selective application of an electromagnetic or fluidic force. In one embodiment, the end pieces are all formed of the same material or composition of materials. In an alternative embodiment, the end pieces are each formed of different materials, whereby the end pieces are differentially susceptible to distinct electromagnetic or fluidic forces. Examples of suitable materials are those known to be susceptible to electromagnetic or fluidic force, such as a dielectric material, a magnetic material, a metallic material, and a ferro-electric material. In one specific embodiment, wherein at least a portion of the end pieces are formed of a dielectric material, the dielectric material includes an electret.
In one embodiment, the end pieces have a diameter greater than that of the wire to which they are attached. In one specific embodiment, the end piece is a bead, having a suitable shape, such as that of a sphere. Typically, the bead will have a diameter in a range of between about 30 microns and about 100 microns. Alternatively, the end piece can be in the form of a spool about which the wire to be braided, woven or twisted is wound. In some embodiments, the beads or spools are formed of a uniform material. In an alternative embodiment, the beads or spools are formed in layers having distinct electromagnetic properties. For example, in one embodiment, the beads can include a magnetic core.
In one embodiment, the end piece are beads that are attached to a first end of each of a plurality of wires by a suitable means. In one embodiment, the bead is a metal bead that is attached to a nanowire by a suitable glue, such as a UV-curable epoxy glue. In one specific embodiment each metal bead is attached to a respective first end of the plurality of wires by first affixing each nanowire to the surface of a fluorinated ethylene polypropylene (FEP) sheet. A drop of UV-curable epoxy glue is then applied with a micropipette to the first end of the nanowire and a micromanipulator arm is employed to lower a metal-coated bead onto the bead of UV-curable epoxy glue. UV light can then be employed to cure the epoxy, thereby fixing the bead to the first end of the nanowire.
The second ends of each of the wires are fixed relative to each other. In one embodiment, the wires are fixed at their respective second ends to each other. In an alternative embodiment, the wires are fixed at their respective second ends to a fixed support and are proximate to each other. In either case, the end pieces are suspended by the wires from the point at which the second ends of the wires are fixed to each other or to a separate support by a suitable force, such as gravity.
The end pieces are manipulated by selective application of an electromagnetic or fluidic force that braids, weaves or twists the wires to thereby form the braided, woven or twisted wire. The beads or spools of the end pieces can be manipulated in two dimensions or three dimensions. The end pieces are manipulated relative to each other by suitable means, such as by employing an addressable platform. For example, where the end pieces are manipulated relative to each other by selective application of an electromagnetic force, the selective application of that force can, in one embodiment, be obtained by a planar, or semi-planar grid of patterned electrodes. The patterned electrodes can exist in a single layer or in multiple layers whereby selective actuation of the pattern of electrodes directs the end pieces, whether they be beads or spools, or some other configuration, across the patterned surface relative to each other in a manner that causes the wires to which the end pieces are attached to form a braided, woven or twisted wire.
The platform of electrodes, in turn, is fabricated by a suitable method, such as by photo lithography. Examples of suitable materials to fabricate an addressable platform can be found, for example, in Zemánek, et al., “Dielectric actuation strategy for micromanipulation along complex trajectories.” IEEE/ASMI Int'l. Conf. on Advanced Intelligent Mechatronics (AIM) (2014), the relevant teachings of which are incorporated herein by reference in their entirety.
In one embodiment, the wires are all fixed relative to each other at a constant distance from the grid providing selective application of electromagnetic force, as shown in
The teachings of all patents, published applications and references cited herein are0 incorporated by reference in their entirety.
While this invention has been particularly shown and described with references to example embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the scope of the invention encompassed by the appended claims.
This application claims the benefit of U.S. Provisional Application No. 62/211,139, filed on Aug. 28, 2015. The entire teachings of the above applications are incorporated herein by reference.
This invention was made with government support under contract FA8650-15-7543 from the Air Force Research Laboratory. The government has certain rights in the invention.
| Number | Date | Country | |
|---|---|---|---|
| 62211139 | Aug 2015 | US |
