JP2009525620A - Proximity electrode with uniform gap - Google Patents

Abstract

Improved designs have been disclosed to maintain the separation between electrodes in tunnels, diodes, thermionics, and thermophotovoltaic. At least one electrode is made of a flexible material. A magnetic field exists to generate a force that combines with the current flowing in the flexible electrodes and balances the electrostatic force or other attractive force between the electrodes. Force balance maintains the separation and parallelism between the electrodes in a very narrow spacing without requiring the use of multiple control systems, actuators or other operating means or spacers. One or both electrode shapes are designed to maintain a constant separation across all overlapping regions of the electrode. The result is a simple structure that is simple and easy to manufacture, with a uniform gap over a wide area, keeping two closely spaced parallel electrodes between them stable and parallel, Used to cool electricity or electricity.
[Selection] Figure 1

Description

  The present invention relates to diodes, thermoelectrons, tunnels, thermophotovoltaic, and other devices that are designed with very narrow spacing between electrodes and in some cases require thermal insulation between the electrodes. The present invention can be applied to thermal tunnel / thermophotovoltaic generators and heat pumps, and can be applied to similar systems using thermionic and thermoelectric methods. These thermal tunnel generators and heat pumps convert heat energy into electrical energy and perform refrigeration when operating in reverse. The present invention is also applicable to devices that require a spacing between two adjacent parallel electrodes through which current flows.

  The phenomenon that high-energy electrons flow from one conductor (emitter) to another conductor (collector) is used for many purposes in many electronic devices. For example, the vacuum tube diode was provided in this way, and its physical phenomenon was called thermionic emission. Due to the limitations imposed by the relatively wide physical spacing available, these diodes had to operate at very high temperatures (above 1000 Kelvin temperatures). In order to overcome the high quantum barrier by gaining enough energy for the electrons to travel a long distance to the collector, the hot electrode needed to be very hot. Nevertheless, vacuum tubes allowed the construction of electronic diodes and later amplifiers. Over time, these devices were optimized by coating the electrode with an alkali metal or oxide such as cesium to reduce the operating temperature. Although the temperature of thermionic generation is still much higher than room temperature, this power generation method is effective in converting heat from combustion or solar concentrators into electricity.

  Later, it was discovered that if the emitter and collector were very close to each other with an interatomic distance on the order of 2 to 20 nanometers, electrons would flow at a much lower temperature, even at room temperature. At this narrow interval, the electron clouds of the atoms of the two electrodes are very close, so hot electrons actually flow from the emitter electron cloud to the collector electron cloud without physical conduction. This type of current when the electron clouds cross but the electrons are not in physical contact is called a tunneling current. A scanning tunneling microscope uses, for example, a pointed conductive needle very close to the conductive surface, and the atomic contour of this surface is delineated by illustrating the current flow as the needle scans the surface. U.S. Pat. No. 6,057,059 teaches such a method applied to scanning tunneling microscopy.

  If such atomic separation is maintained over a large area (eg 1 square centimeter), a large amount of heat is converted to electricity by a single device such as a diode, which can be used as a refrigeration system or various sources It is known in the industry that it will be effective in recovering unused heat energy from the industry. See Non-Patent Document 1, Non-Patent Document 2, and Non-Patent Document 3. The spacing between the electrodes must be narrow enough to allow “hot” electrons (electrons with energy above the Fermi level) to flow, but usually allow conduction (electron flow below the Fermi level). Must not be close. There is an effective range of separation distances of 2 to 20 nanometers that allows conversion from electricity to refrigeration of thousands of watts per square centimeter. See Non-Patent Document 1 above. These references also suggest the advantage of having a coating or monolayer of alkali metal or other material on the emission electrode to achieve a low work function in the transfer of electrons from one electrode to the other. . This coating or monolayer further reduces the operating temperature and increases the conversion efficiency.

  Mahan reveals that the theoretical efficiency of a thermionic refrigeration system using a low temperature electrode of 500 e with a work function of 0.7 eV is higher than 80% of the Carnot efficiency. See Non-Patent Document 4. By analogy, the conversion efficiency of the electron tunnel process is also expected to have a high Carnot efficiency. Carnot efficiency represents the upper limit of achievable thermal energy conversion efficiency.

  Maintaining electrode separation in the atomic dimension over a large area was the single most important challenge in building devices that remove heat from conductors. For example, a scanning tunneling microscope requires a special laboratory environment without vibrations and its operation is limited to a range of a few square nanometers. Most recently, all measurements of cooling in actuators are limited to a few square nanometers. See Non-Patent Document 3.

  Separation of electrodes with relatively large dimensions of about 100 nanometers can aid in the conversion of heat to electricity using thermophotovoltaic methods. In a thermophotovoltaic system, photons pass through the gap. If one photoelectron emitting electrode emits from a heat source and the second photosensitive electrode is not as far apart as the emission wavelength, up to 10 times the conversion power of a standard photovoltaic system is possible. is there. The heat source may be focused sunlight, fossil fuel combustion, or other means. The photoelectron emission electrode may be made of tungsten, for example. The photosensitive electrode may be made of silicon, selenium or indium gallium arsenide. See Non-Patent Document 5 for further information on thermophotovoltaic methods.

Thus, there remains a need for devices that cost effectively and efficiently convert thermal energy to electrical energy in packages that are convenient for use in both heat sources as inputs and electrical circuits that require power as outputs. An abundant heat source including exhaust heat can be easily used as a power source. Examples of where such a device is useful for the environment, saves money, and both are possible:
(1) Convert solar heat and light to electricity more cost-effectively than currently used photovoltaic devices. Many publications describe high temperature thermionic emission for recirculating thermal energy from solar concentrators by using such thermal conversion devices. See Non-Patent Document 4 above. However, if tunneling is performed at naturally occurring temperatures, such a conversion will be even less expensive and more prevalent.
(2) recovering the heat generated by an internal combustion engine, such as that used in automobiles, into a beneficial exercise. Some currently available vehicles, called hybrid gas electric vehicles, can generate motion using either electric power or internal combustion. In current internal combustion engines, about 75% of gasoline energy is converted to exhaust heat. A tunnel conversion device can recover most of this thermal energy from the engine of a hybrid vehicle and place it in a battery for later use. U.S. Pat. No. 6,057,056 teaches a method of converting heat from a combustion chamber and storing this energy or converting it into motion.
(3) To reduce the need for harmful gases to enter the atmosphere. More energy efficient hybrid vehicles are an obvious example in which harmful exhaust gases released into the atmosphere are reduced. Devices that convert engine heat and exhaust heat of a hybrid engine and then store it or generate electricity with a hybrid battery further increase the efficiency of the hybrid vehicle and reduce the need for exhausting harmful gases. The coolant used for refrigeration is an example of another harmful gas that needs to remove heat, and the tunnel conversion device will reduce the need to release harmful gases.
(4) Collect heat energy when it is available, store it in the battery as chemical energy, and reuse it when it is not available. The tunnel converter would be able to convert solar energy into electricity during the day and store it in the battery. At night, the stored battery power can be used to generate electricity.
(5) Power generation from geothermal energy. Heat exists in many places on the earth's surface and is virtually infinite deep in the earth. Any effective tunnel conversion device could use this energy supply.
(6) Implementation of refrigeration using a solid state device that is small and quiet. In this case, such a tunnel device would provide cooling or refrigeration for the air conditioner and could replace the need for large air machines and compressors.
(7) Power generation from body temperature. The human body generates about 100 watts of heat, which can be converted into useful power for handheld products such as mobile phones, cordless phones, music players, personal digital assistants, flashlights and the like. Thermal conversion devices as presented in this disclosure can generate enough power from heat applied by partial contact with the human body to operate and charge the batteries for these handheld products.
(8) Electric power from burning fuel. Wood stoves generate tens of thousands of watts of heat. Such tunnel devices can generate 1 or 2 kilowatts from this heat, which is sufficient to power a typical household appliance. Similar applications are possible by burning other fuels such as natural gas, coal, etc. This way, even in remote homes, you can get modern conveniences without the need for a power grid connection or a noisy generator.

  If two parallel electrodes are to be provided together in a separation gap of less than 20.0 nanometers, two parameters need to be noted. One is surface roughness and the other is surface flatness. Surface roughness is the difference from a smooth state in a narrow local area. Holes and flaws are examples of differences that affect surface roughness. The surface flatness is a difference from the parallel state in a wide range. Warpage, bending, and creep are examples of differences that affect surface flatness.

  If the two grid materials are polished flat using the best techniques available today for integrated circuits, the surface flatness will be on the order of micrometers over a range of one square centimeter. Furthermore, heat and other stresses cause warping and bending changes over time, creating additional challenges in maintaining uniform separation once achieved. A surface of metal or semiconductor polished using current technology can easily achieve roughness of less than 0.5 nanometers.

  State-of-the-art tunnel energy conversion devices are subject to one or more of the following constraints: (1) Separation too wide for tunneling, (2) Range too narrow for mass energy conversion, (3) Layer of solid material that cannot be adiabatic and consequently has low conversion efficiency, (4) Cost efficiency Design too complex to produce well.

  Many thermionic systems perform separations of 10 microns or more, but these systems operate only at very high temperatures, require costly designs for safety, and are limited to environments where this temperature is achieved Is done.

  A separation of about 2.0 to 20.0 nanometers has been implemented in the design of scanning tunneling microscopes by the method taught in US Pat. Such a range is too narrow (compared to the desired range of about 1 square centimeter or more) to carry enough current to convert a large amount of energy, even for the optimal material.

  The semiconductor industry teaches and employs many methods for controlling physical parameters such as film thickness on the order of a few nanometers. A thermoelectric device is an example of an integrated circuit that converts energy by a stack of layered materials. See Non-Patent Document 7. However, all these methods require that the solid materials come into contact with each other within the layer. Heat easily flows from layer to layer, limiting temperature differences and conversion efficiency. Because the two electrodes are in contact, the design depends on the available thermoelectric sensing material, and the energy barrier to electron traversal is made possible by setting the width of the vacuum gap and cannot be arbitrarily determined. . Materials with the necessary properties are new types of expensive elements such as bismuth and tellurides. For these reasons, thermoelectric devices are costly per watt cooling and are limited to a low efficiency of about 7 percent.

  The technique of separating two conductors by about 2.0 to 20.0 nanometers over a square centimeter range has been advanced by the use of an array of feedback control systems that are very accurate over these distances. The control system includes feedback means for measuring the actual separation and comparing it with the desired separation, and moving means for moving the elements close or apart to maintain the desired separation. The feedback means can measure the capacitance between the two electrodes, which increases as the separation decreases. The moving means for these dimensions is in the state of the art actuators that generate movement through piezoelectric, magnetostrictive and electrostrictive phenomena. Patent Document 3 describes a design that includes forming one surface with another surface and then using a feedback control system to complete the parallel state before use. This design approach precludes low cost manufacturing due to the complex processes involved in shaping one surface against the other and the use of multiple feedback control systems to maintain parallelism.

  Other methods are documented in US Pat. Nos. 5,098,086 and 5,058,6, which involve inserting a “sacrificial layer” between the electrodes during manufacture. Thereafter, when the sacrificial layer evaporates, a gap close to the desired spacing of 2 to 20 nanometers is formed between the electrodes. These three methods are susceptible to post-manufacturing variations due to warpage or thermal expansion differences between the electrodes, or require an array of actuators to compensate for these variations.

  Another way to implement and maintain the desired spacing over time is through the use of dielectric spacers that maintain the spacing of the flexible electrodes as well as the poles supporting the tent. 8 is recorded. One of the disadvantages of these dielectric spacers is that they transfer heat from one electrode to the other, reducing the efficiency of the conversion process. Another disadvantage of this method is that in the presence of a large electrostatic force, the flexible metal electrode stretches or deforms between the spacers over time and moves slowly towards the spacing, thus tunneling or thermionic emission. Instead of conducting.

  Another method for implementing the desired vacuum spacing between the electrodes is disclosed in US Pat. No. 6,057,089 by forming a narrow gap at the interface between the two bonded wafers. These voids are narrow enough to allow thermal tunneling of electrons in gaps of a few nanometers. Although these gaps aid in thermal tunneling, unnecessary heat conduction occurs around the gaps and it is difficult to control the uniformity of the electrode spacing.

  Yet another method of providing a thermal tunneling gap is by contacting the opposing surfaces of two wafers and then separating them several nanometers using an actuator, as described in US Pat. . Although this method can generate a thermal tunneling gap, this method suffers from the cost of multiple actuators and heat conduction between wafers outside the gap range.

  Despite ongoing efforts to meet the requirements to achieve and maintain electrode spacing with a separation gap of less than 20.0 nanometers in mass-produced low cost thermal tunnel devices Remaining.

  An additional utility for devices that can move electrons in a vacuum gap (in addition to performing direct cooling) is to provide this gap on top of the thermoelectric stack. This combination is more efficient because the high temperature side and the low temperature side of the thermoelectric gap are insulated. A device comprising a combination of a thermoelectric material and a vacuum gap can be cooled or thermally converted via a thermoelectric method, a thermal tunneling method, a thermoelectronic method, or a combination of these methods.

US Pat. No. 4,343,993 US Pat. No. 6,651,760 US Pat. No. 6,720,704 US Pat. No. 6,774,003 US Patent Application Publication No. 2002/0170172 US Patent Application Publication No. 2001/0046749 US Pat. No. 6,876,123 US Patent Application Publication No. 2004/0050415 US Patent Application Publication No. 2004/0195934 US Patent Application Publication No. 2006/0000226 Y. Hisinuna, T .; H. Geballe, B.M. Y. Moyzhes, T .; W. Kenny's "Efficiency of refrigeration using a thermal tunnel and thermionic emission in vacuum: use of nanometer-scale design" (Applied Physics Communications Vol. 78 No. 17: April 23, 2001) Y. Hisinuna, T .; H. Geballe, B.M. Y. "Vacuum thermoelectron refrigeration by semiconductor heterojunction structure" by Moyzhes (Applied Physics Communications Vol. 81, No. 22: November 25, 2002) Y. Hisinuma, T .; H. Geballe, B.M. Y. Moyzhes, T .; W. Kenny's “Measurement of Cooling by Room Temperature Thermionic Emission in the Nanometer Gap” (Applied Physics Journal Vol. 94, No. 7: October 1, 2003) G. D. “Thermo-Electron Freezing” by Mahan (Applied Physics Journal, Volume 76, No. 7: October 1, 1994) R. Di Matteo, P.M. Greiff, D.C. Seltzer, D.C. Meulenberg, E.M. Brown, E.I. Carlen, K.M. Kaiser, S .; Finberg, H.M. Nguyen, J. et al. Azarkevic, P.A. Baldasaro, J. et al. Beausang, L.M. Danielson, M.C. Dashiell, D.C. DePoy, H.M. Ehsani, W.H. Topper, K.M. Rahner, R.A. “Micron-Gap Thermophotovoltaic (MTPV)” by Siergie (American Physical Society, 6th Thermophotovoltaic Power Generation Conference: 2004) G. D. Mahan, J. et al. A. Sofao, M .; “Multilayer Thermoelectric Refrigerator” by Bartkoiwak (Applied Physics Journal, Volume 83, No. 9: May 1, 1998) Chris LaBounty, Ali Shakouri, John E. et al. “Design and Features of Thin Film Microcoolers” by Bowers (Applied Physics Journal Vol. 89, No. 7: April 1, 2001) A. N. Korotkov, K.K. K. “Cooling by resonance Farr-Nordheim emission” by Likharev (Applied Physics Communications Volume 75 No. 16: August 23, 1999)

  Therefore, there is a need for an improved design to maintain vacuum isolation between electrodes in tunnels, diodes, and other devices that are more efficient and less expensive than existing designs. In particular, there is a need for a design having a proximity electrode with a uniform vacuum gap. More specifically, the need for a design with a pair of electrodes that self-align and self-align in the close gap between the electrodes to move the electrons in the gap, possibly due to tunneling in combination with thermoelectric elements, thermionics, and other emissions. Sex exists.

  The present disclosure is directed to overcoming the foregoing or other problems and disadvantages of the prior art. Disclosed are devices and processes that employ electron flow in ways not previously thought of in the prior art. In previous designs, the flow of electrons in the tunnel device was used for two purposes. (1) as a thermodynamic fluid for transferring heat from one conductor to another, (2) for directly transferring conversion energy to or from the battery or electrical circuit. In the present invention, device structures and processes are provided in which electron current is also used to generate a restoring force that balances electrostatic forces or other attractive forces at the desired electrode separation.

  Devices and processes for providing proximity electrodes with uniform gaps are disclosed. More specifically, the present disclosure provides self-alignment and self-alignment in the close gap between the electrodes to allow movement of electrons in the gap, possibly by tunneling, thermoelectrons, and other emissions combined with thermoelectric elements. It relates to a pair of electrodes.

  The present invention uses a flexible material on one of the electrodes and naturally places the flexible electrode in a stable equilibrium position at a desired spacing distance from the surface of the other electrode over a wide range. And a magnetic field that balances the simultaneously acting magnetostatic repulsive force with electrostatic or other attractive forces to accommodate the difference between continuous and spatial flatness at either electrode.

  By polishing the opposing surface of the electrode prior to assembly, a surface roughness of less than 0.5 nanometer is achieved. Polishing techniques are readily available in the industry to achieve surface roughness of less than 0.5 nanometers for metals, semiconductors and other materials.

  In order to achieve a separation of less than 20.0 nanometers over a wide range of 1 square centimeter or more, a non-contact force combination is generated that causes the electrode material to rest at the desired spacing. In stable equilibrium conditions, one force already present in these diode devices is the electrostatic force between the emitter and collector. When a voltage is applied, opposite charges collect at each of the electrodes, and the presence of these charges creates an attractive force between the electrodes. Although the electrostatic force is considered to be the dominant attractive force in the proximity electrode, other attractive forces such as gravity, surface tension, van der Waals force, kashmir force, and static friction also exist.

  One aspect of the present invention is an equivalent and opposite orientation that acts on the flexible electrode to balance the electrostatic and other attractive forces at all points so that the flexible electrode maintains the desired spacing and alignment. A second force is generated. This second force is due to a physical phenomenon in which a force is generated when a current flows through the conductor in the presence of a magnetic field. This force acts in a direction perpendicular to the plane defined by the direction of the current and the direction of the magnetic field.

  By providing a permanent magnet near or in the electrode, a magnetic field can be added to the embodiments of the present invention. Permanent magnet materials such as iron, cobalt, nickel, and their alloys are also highly thermally and electrically conductive metals. These magnetic materials are therefore compatible with the thermal and electrical conductivity of the electrodes. Even if it is desirable to provide a magnetic field using a non-conductive magnetic material, such a magnet is covered with a conductor or simply a flat conductor is attached to the magnet in order to constitute the emission electrode.

  Since the magnetic material loses magnetism at Curie temperature levels, typically 600 to 1400 Kelvin degrees, the temperature of the surface on which the permanent magnet is provided affects the operating parameters of the permanent magnet. However, in the present invention, since the magnet is provided on either the low temperature side or the high temperature side of the conversion device, a structure that prevents the magnet from reaching the Curie temperature can be found.

  The present invention provides a new, non-obvious way of bringing electrode materials together in order to produce simple and inexpensive thermal tunneling, thermophotovoltaic or thermoelectronic devices with the following advantages. (1) simplicity by avoiding the need for actuators and control systems required by the prior art; (2) low-cost mass utilizing technology and manufacturing processes already developed in the light bulb and semiconductor industries. Carrying out production, (3) realizing a narrow gap between the electrodes without spacers, so as to allow the tunneling of hot electrons from one electrode to the other and cool the first electrode, (4) Maintain a uniform spacing gap over a wide electrode range such as 1 square centimeter.

  Other systems, devices, features, and advantages of the disclosed devices and processes will be apparent to those skilled in the art or upon review of the following drawings and detailed description. All additional systems, devices, features, and advantages are included in this description, are within the scope of the invention, and are protected by the accompanying claims.

  Many aspects of the disclosed devices and processes can be better understood with reference to the accompanying drawings, FIGS. The parts in the drawings are not necessarily to scale, emphasis instead being placed upon clarifying the principles of the invention. Moreover, in the drawings, like reference numerals do not require corresponding parts in all of the several figures. Although embodiments have been disclosed with reference to the drawings, there is no intention to limit the disclosure to the disclosed embodiments. On the contrary, what is intended is to have all alternatives, modifications and equivalents.

  Referring more particularly to the drawings in which like reference numerals refer to like elements throughout the several views, embodiments of the devices and processes of the present disclosure are illustrated in FIGS.

  In general, devices and processes are disclosed that employ counter electrodes and involve two force distributions. The main electrostatic attraction distribution between the electrodes is generated by the charge in the electrodes. Due to the current distribution in the electrode combined with the applied magnetic field distribution, an equal and opposite repulsive force distribution is generated. The two force distributions act simultaneously to establish a stable and balanced separation of the electrodes at the opposing surface.

  FIG. 1 illustrates one embodiment of the present disclosure. The electrode 1 is a flexible metal foil, that is, a plastic film such as polyimide, or a metal foil attached to a substrate. The plastic substrate helps to prevent the metal foil from cracking, breaking or breaking after repetitive motion caused by electrostatic and electromagnetic forces. The plastic substrate or electrical properties of the electrode 1 also serve to avoid vibrations during equilibrium, i.e. operational instability. The electrode 2 is a permanent magnet made of or coated with a conductive material. In an example of the shape, the electrode 2 is a rectangular block. Both electrodes have their surfaces facing each other polished. A heat source 30 is present when the device is used for heat energy conversion, and is an object to be cooled when the device is used as a refrigeration apparatus. A power supply 10 is present when the device is used as a refrigeration device, and an electrical load when the device is used as a heat conversion generator. An insulating layer 4 is present to provide a non-conductive contact point for the tip 6 of the electrode 1 when the device is not in operation (i.e., while the device is deactivated). In addition, one of the electrodes has a coating of non-conductive material that is thinner than the desired equilibrium spacing between the electrodes against which the other electrode abuts when the device is not in operation. The top layer or coating 5 of electrode 2 is a material designed to have a low work function that facilitates electron tunneling between electrode 2 and electrode 1. Connectors 9a, 9b and wires 8a, 8b complete the circuit. Chamber 20 seals the area between opposing electrodes 1, 2 with a vacuum or inert gas to minimize heat transfer from one of the electrodes to the other. Suitable gases include argon and helium. The wide end of the flexible electrode 1 is fixed to the support structure of the chamber 20, and when the power is turned off, the electrode 1 contacts the insulating layer or film 4 at the tip 6.

  FIG. 1 a shows the directional state of the current (I) flowing through the electrode 1, the magnetic field (B) generated by the presence of a permanent magnet in the electrode 2, and the force F resulting from the interaction between I and B. . The force F acts in a vertically upward direction at every point on the electrode 1 and balances against the electrostatic attractive force that pulls the electrode 1 downward to the electrode 2.

  FIG. 1 b shows an alternative configuration of electrode 2. Here, the surface of the material is patterned by an array of tops 5. Due to the electromagnetic field in these top regions, the top geometry facilitates electron emission from the electrode 2. These tops may naturally occur due to intentional or unintentional roughness of the surface of the electrode 2 after polishing.

  The device of FIG. 1 also has an additional force generation / modification mechanism or system that assists in the operation of the device during power off, equilibrium or transition from power off to equilibrium or from equilibrium to power off. For example, these mechanisms attenuate the system so as to prevent vibration of the electrode 1 around the equilibrium abutment position. These additional forces may be generated mechanically, magnetically, electromechanically, electromagnetically, or by other methods that compensate for excess or deficiency of the main static and magnetic balance forces.

  The material of the flexible electrode 1 may be a conductive metal, a semiconductor material, a layered glass / metal or a layered metal / plastic. Examples of the conductive metal include gold, silver, aluminum, and copper. Examples of semiconductor materials are silicon, germanium, and gallium arsenide. The conductive metal or semiconductor material is optional and can be attached to a material such as glass, polyamide, polyester, polyimide, polyacryl or polyolefin that adds flexibility to the metal if the metal is not sufficiently flexible by itself , And may be combined with this material in layers.

  The permanent magnet of the electrode 2 may be provided on the electrode or a part thereof. In an exemplary embodiment, the permanent magnet may have a conductive ferromagnetic material combined with iron, cobalt, nickel, neodymium or aluminum. Alternatively, the permanent magnet may have one or more non-conductive ferromagnetic materials coated with a conductive material. Examples of non-conductive ferromagnetic materials include ferrite, barium ferrite, and iron oxide particles sealed with a binder.

  The layer or coating 5 on the electrode 2 may be a low work function material, a thermoelectric sensing material, a resonant tunneling material, an electric field enhancing texture, or a combination thereof. Typical examples of low work function materials include layered alkali metals, alkali metal alloys, oxides, diamonds such as diamond films, nanotubes, or other combinations. A collection of tops and troughs resulting from surface roughness or patterning (eg as illustrated in FIG. 1b) enhances the electric field and improves electron emission from the electrode 2. Finally, a semiconductor layer configured to achieve resonant tunneling also improves electron emission. Typical semiconductor materials include silicon, germanium, and gallium arsenide. Typical thermoelectric sensing materials include bismuth telluride with various dopings.

  The low work function material of the layer 5 of FIG. 1 or the reinforcing material 5 ′ of FIG. 1b is, for example, cesium (Cs), barium (Ba), strontium (Sr), rubidium (Rb), germanium (Ge), sodium (Na ), Potassium (K), calcium (Ca), lithium (Li), and combinations or oxides thereof. Such materials have been found to reduce the work function of the emission electrode 2 from 4-5 eV to 1.1 eV or less. Other low work function materials include thorium (Th), metal-clad oxide, and silicon. Other materials not mentioned here can also achieve low work functions, and the addition of such material layers is a trivial extension of the present invention. For example, Korotkov has proposed a different type of layer for promoting electron tunneling, a wide gap semiconductor layer. See Non-Patent Document 8. Here, a thin oxide layer with carefully controlled thickness excites electrons to resonance conditions, thereby helping hot electrons to be released into the vacuum. Also, layer 5 of FIG. 1 and 5 'of FIG. 1b may be an array of carbon nanotubes or similar configuration to maximize emission and minimize work function. The insulating layer 4 material includes glass, polyimide, and other plastics.

  The flow of electrons in FIG. 1 and the uniqueness of the present invention will be described below. Free electrons flow from the power supply or electrical load 10 to the emission electrode 2. The free electrons emitted from electrode 2 to electrode 1 are selected by this design to be high temperature electrons that can remove heat from electrode 2. One aspect of the present invention is that free electrons flow in the electrode 1 from left to right in FIG. 1 in the presence of the magnetic field B whose direction is shown in FIG. This free electron flow direction is combined with the applied magnetic field to balance the electrostatic attraction and achieve a constant and desired separation between electrode 1 and electrode 2 over a wide range, the direction being shown in FIG. Generate a repulsive force.

  FIG. 2 is a schematic top view of an exemplary embodiment of the electrode 1 of FIG. 1 showing a cross section 7 with an arrow pointing in the direction of electron flow. Cross section 7 has a current density equal to the collective tunneling current picked up by all 7 left electrode surfaces divided by the length of cross section 7. Since the tunneling current is predicted to be proportional to the range of the 7 left-hand tunneling action, the length of the cross-section 7 is appropriately increased in proportion to the increase in the range of the left electrode surface. Therefore, the boundary line 3 of the electrode 1 draws an exponential function. Thus, the width of the surface of the flexible electrode 1 increases exponentially from the tip 6 to the opposite end. The exponential function is mathematically equal to the range enclosed by it and the X axis up to the integration point. The function drawn by the boundary 3 can correct other changes in current density, such as electrical resistance due to the path length in the electrode 1. Also, in some cases, the design can be sub-optimized by the triangular electrode 1 for ease of manufacture.

  FIG. 2a is a schematic view of the bottom side of the excised portion of the electrode 1 shown in FIG. It shows how the electrode 1 is patterned on the bottom surface facing the electrode 2. Depending on the pattern, the tunneling area (defined by the total area X of the raised surface x) differs from the total area Y available for current flow. By patterning the electrode 1 in this manner, the total area Y is widened, and hence the electrical resistance loss and the heat generation loss are reduced so that the collective current flows. At the same time, the area close to the electrode 2 is minimized, which reduces the electrostatic force that must be exceeded to place the electrode in the desired position. The same effect of patterning the electrode 1 can also be achieved by intentional or unintentional surface roughness after polishing. Intermittent ridge segment 4 is a thin insulating layer that supports electrode 1 and prevents a short circuit when the foil material of electrode 1 becomes pleated into electrode 2 when the device is activated.

  FIG. 3 is a schematic diagram illustrating another embodiment of the present disclosure that can achieve a smaller package. Here, the electrode 2 is a cylindrical permanent magnet having a magnetization direction that diverges radially outward from the center. At this time, the electrode 1 takes the shape of an exponential spiral whose width exponentially increases with each rotation. Alternatively, the electrode 1 may have a linear incremental spiral shape that more easily resembles an exponential spiral shape for ease of manufacture. Since the electrode 1 has a spiral shape, the current flows in the tangential direction. The force on electrode 1 acts in the vertical direction to provide a repulsive force that balances the electrostatic attraction similar to that achieved in FIG. This embodiment is a more compact design due to the helical shape of the electrode 1 because the total tunnel area does not need to be extended over one long dimension as in FIG. Cylindrical magnets with radial magnetism (measuring a radial magnetic field from the center of the device) are commonly available in the industry because they are common in loudspeaker construction. The remaining parts of this embodiment are the same as in FIG.

  In addition to the embodiment of FIGS. 1 and 3, there are many other obvious embodiments of the present invention that use one specially shaped electrode to achieve a uniform repulsive force. FIG. 4 is a schematic diagram of such another embodiment. Instead of a change in electrode width, a change in magnetic field is used. For example, in FIG. 4, since more current is available in the tunnel range, the current density of electrode 1 increases from left to right. To achieve a uniform force across the electrode 1, the required magnetic field strength is reduced when a higher current density is obtained, so the magnetic field decreases from left to right. Thus, the magnetic field strength changes in inverse proportion to the current density of the flexible electrode 1 so as to achieve a constant force. One way to reduce the magnetic field from left to right is to change the depth of the permanent magnet material 23 provided on the electrode 2 to increase the amount of non-magnetized material 24 such as copper or aluminum.

  FIG. 5 is a graph showing how the forces interact to provide a constant spacing between two electrodes in the tunnel range in FIGS. The Y axis 40 is force, and the X axis 41 is the gap gap width or separation distance between the electrodes. Curve 43 represents the electrostatic attraction between electrode 1 and electrode 2. The force indicated by the curve 43 is inversely proportional to the square of the gap 41. Curve 46 shows the repulsive force between two electrodes generated by a tunneling current that flows in the presence of a magnetic field. This current approaches zero until the separation becomes narrow enough for tunneling to occur. Second, it rises very rapidly as the spacing further decreases. The location of the tunneling separation point 42 and the complete conduction separation point 44 depends on the process conditions used. According to Hisinuma, for example, in a device with an applied potential of 0.1 to 2.0 volts, the tunneling start separation point 42 is approximately 20 nanometers and the essentially complete conduction point 44 is approximately 1 nanometer. . See Non-Patent Document 1 and Non-Patent Document 3 above. The attractive force and the repulsive force are equal at point 45. This is a separated state where the device is in a stable equilibrium position. When the separation state becomes larger than the point 45 due to some interference with the device, the attractive force 43 tends to overcome the repulsive force 46 and return to the equilibrium point 45. Similarly, if any interference is applied to lower the separation state below the point 45, the repulsive force 46 overcomes the attractive force 43 and returns the device to the equilibrium point 45 again.

  In addition to the electrode configuration described above, the electrodes may be arranged in multiple layers with periodic spacing. In addition, to achieve a high level of energy conversion, multiple units of the device may be assembled in series, in parallel, or in parallel and in series.

  In operation, the current distribution, that is, the density of the flexible electrode 1 and the strength of the magnetic field of the counter electrode 2 are adjusted so that the electrode is disposed at an equilibrium position in a stable separated state. In one example, when the device of the present disclosure is used to convert heat to electrical energy or to cool using electron tunneling or a combination of thermoelectron transfer, electron tunneling and thermionic principles, The current density or distribution of the electrode 1 and the magnetic field of the electrode 2 are arranged so that the counter electrode is placed at an equilibrium position in a stable separated state in the range of 1 nanometer to 20 nanometers using a flexible metal foil for one electrode. And the intensity is adjusted. In another embodiment, when the device of the present disclosure is used for cooling by thermal electron transfer or heat conversion to power generation, using a silicon wafer as the substrate for one or both electrodes, The strength of the current density, that is, the distribution of the electrode 1 and the strength of the magnetic field of the electrode 2 is adjusted so that the counter electrode is arranged at an equilibrium position in a stable and separated state.

  The devices of the present disclosure can be used in processes that convert heat to cooling or electrical energy. The heat source may be a radiation source such as solar radiation, heat from the environment, geothermal energy, engine or heat from the human body, but not limited to animal metabolism. The heat source can also be from an operating electric machine, steam, an internal combustion engine, or by burning fuel in a stove such as a wood stove, coal stove, other types of stove, etc. It may be exhaust gas. When the heat source is, for example, from an operating internal combustion engine or its exhaust gas, the device may be incorporated into the engine or gas exhaust pipe as a heat sink. The fuel for combustion may be wood, natural gas, coal, or other combustible fuel. The converted energy is stored in a battery or the like or sent to power a handheld electrical device such as a mobile phone, cordless phone or other product as described above.

  The operation of the device of the present disclosure when operating as a refrigeration apparatus will now be described. Referring again to FIG. 1, a voltage rising from zero is applied between the electrode 1 and the electrode 2 by the power supply 10. This voltage results in an electrostatic force that pulls the tip 6 of the electrode 1 to the surface of the electrode 2. As the voltage gradually increases, the flexible electrode 1 bends downward to the surface of the electrode 2 so as to be rounded starting from the tip 6. This bending continues until the electrode 1 approaches the electrode 2 as the tunnel current starts to flow upward from the electrode 2 to the electrode 1. Once this tunnel current reaches the electrode 1, it flows horizontally to the right in the electrode 1 toward the connector 9. This current flows in the direction I in FIG. 1a, and since the magnetic field generated by the permanent magnet of the nearby electrode 2 is in the B direction, a force acts to push the electrode 1 upward. As long as the voltage from the power supply 10 continues to rise, the electrode 1 becomes flat and the surface of the electrode 2 matches the contour. The electrostatic force acts to attract the two electrode surfaces to each other, and the opposing force from the current of electrode 1 prevents the two electrodes from coming closer than desired.

  The operation of the device of the present invention as a power generation device is similar except that the heat source 30 generates “hot electrons” that move from the high energy state of the electrode 2 at a high temperature to the low energy state of the electrode 1 at a low temperature. ing. It is this transfer of electrons from one energy state to another that generates a current between the electrodes. The electric load 10 serves as a sink for the electric energy thus generated.

  In the freezing operation, electric energy from the power source is used so as to draw hot electrons from the electrode 2 and cool it. When operating as a generator, the heat source 30 is used to send electrons to a power source.

  Examples The invention is further illustrated by the following examples based on the basic principles of physics combined with experimental data and measurements obtained by the inventors and the scientists mentioned above. These examples are: (1) the device of the present disclosure can be designed and constructed using industry common dimensions and processes, and (2) the amount of generated force results in the desired electrode separation. (3) The electrical properties of the device of the present invention show that it can effectively transport and transmit the converted electrical energy. The example demonstrates the three attributes of the device of the present invention for a thermal tunnel converter with an electrode separation of less than 20 nanometers and a thermo-photovoltaic converter with an electrode separation of about 100 nanometers.

  For the thermal tunnel converter, consider the following dimensions in FIGS.

The total overlapping tunnel area of the counter electrode is 1 square centimeter or 10 ⁻⁴ square meters. The length L of the flexible electrode 1 is 2 centimeters, and the maximum width W is 1 centimeter. The length L and the width W are similarly defined in FIG. 3, but the electrode 1 is wound in a spiral shape as compared with the linear shape of FIG. The opposing surface of the electrode 1 is surface patterned or has surface roughness so that the total tunnel area X (the sum of all x) is one tenth of the total surface area Y, ie 10 ⁻⁵ square meters. The permanent magnet material used for the electrode 2 has a magnetic field strength B of 1.2 Tesla. The voltage V between the electrodes is 0.15 volts. The dielectric constant ε of the vacuum or authorized inert gas between electrodes 1 and 2 is equal to 8.8 × 10 ⁻¹² farads / meter. The resistivity γ of the flexible electrode 1 is close to that of copper, ie 1.7 × 10 ⁻⁸ ohm-meter. It is estimated that the resistance of the electronic path from the upper connector 9a to the other lower connector 9b is sufficiently concentrated on the electrode 1 because it needs to be thin and flexible as compared with the rest of the circuit. The thickness t of the flexible electrode 1 is 20 microns and is therefore a foil material.

The formula for electrostatic attraction Fe is 1 / 2εXV ² / d ₂ , where d is the separation between the electrodes. The formula of the magnetic repulsive force Fm is ILB, I is the current, and L is the effective average length of the current in the electrode 1.

  The tunneling current I as a separation function is obtained from the Hisinuma graph and has a work function of the coating 5 of FIG. 1 of 1.0 eV and an operating temperature of 300 Kelvin degrees. See Non-Patent Document 1 and Non-Patent Document 3 above.

FIG. 6 shows force functions F _m and F _e for the values listed above, with a logarithmic scale on the Y axis and an electrode separation gap d with an arithmetic scale on the X axis. Only when all the quantities have been determined, can a graph like FIG. 5 be obtained from this figure. The stable equilibrium point 45 is close to 2.0 nanometers, and according to Hisinuma, this is the desired spacing range to achieve a 20 amp tunnel current. See Non-Patent Document 3 above. When the spacing gap attempts to shift in any direction from stable equilibrium due to interference, the restoring force is greater than 0.2 Newton, which is sufficient to overcome the bending resistance of the flexible electrode. , Push it back to the equilibrium position.

When the emission electrode is at room temperature, the current is 20 amps, and the voltage is 0.15 volts, the device achieves either 16 watts of power generation capacity or refrigeration capacity, as described in Non-Patent Document 3 above. This is calculated as the current (I) multiplied by the Peltier coefficient of 0.8 used in this example. The resistive force lost by this current flow in the flexible electrode is I ² rL / tw. With the aforementioned values, the ohmic power loss is calculated to be 1.0 watt, which is assumed to be treatable as both the power loss and the heating source electrode 1. Heat transfer from electrode 2 to electrode 1 is also effected by radiation, convection, and conduction, but is estimated to be 1.3 watts or less when the inventive device chamber is evacuated to an argon gas level of 0.06 mmHg. Is done. Finally, as described in Non-Patent Document 3 above, there is electrical heat generated at the electrode 2, which in this example is equal to the voltage V multiplied by the current I, ie about 3.0 watts. is there. The remaining available energy from 16 watts of converted energy is 10.7 watts. This corresponds to a calculated efficiency of 67 percent.

  Thus, it has been found that the system level features of the device based on established electromagnetic theory can support feasible designs and means for practical application to high efficiency thermal tunnel converters.

  Another example of the versatility of the present invention is in material selection. As described in Example 1, the preferred embodiment includes a metal foil as one electrode. In another embodiment, single crystal silicon may be used as the flexible electrode. Silicon is not normally considered a flexible material, but is usually manufactured in the industry to have a roughness of 0.5 nanometers and a flatness of 1 micrometer on a 1 square centimeter surface. It can be seen from the flatness that silicon is much stiffer than a metal foil as measured by Young's modulus, but requires very little bending to achieve ideal flatness. It has been found that the force generated by the present invention can bend the silicon wafer by the 1 micron required to completely flatten the silicon wafer. In general, the use of silicon as a flexible electrode or as a substrate for both electrodes provides several advantages. (1) A silicon wafer can be easily obtained at low cost. (2) Silicon wafers have desirable roughness and flatness characteristics. (3) Adding low work function materials or patterns of materials to silicon is easily and frequently practiced in the industry. (4) The resistivity of the silicon prevents the flexible electrode from reacting too quickly while the flexible electrode is in contact with or nearly in contact with the other electrodes of the present invention. (5) The desired silicon resistivity can be arbitrarily controlled by doping, a common practice again in the industry. The design of the present invention is generally performed by materials and processes commonly available in the semiconductor industry.

  To illustrate an example of the invention using silicon as the flexible electrode, consider FIG. Here, the electrode 1 includes a foil backing 62 and a silicon substrate 65. The shape of the electrode 1 in FIG. 8 is a triangle, which is close to the optimal exponential shape described in Example 1. The silicon substrate 65 may be cut from a standard wafer and bonded to the foil backing 62 of the electrode 1 using a conductive adhesive. The electrode 2 'in FIG. 8 has a structure similar to that of the electrode 2 in FIG. 1, but no magnet is shown, and it is assumed that they are arranged separately. By separating the magnet from electrode 2 ', it is possible to construct electrode 2' of FIG. 8 using the same materials and processes as electrode 1 of FIG. An arrow 61 indicates a flow of electrons having directionality. Since the foil backing has a much higher conductivity than silicon, the electrons take the path of least resistance. Therefore, electrons flow through the foil backing of electrode 2 'from right to left by conduction, and then flow vertically through the silicon substrate of electrode 2' as indicated by arrow portion 67, and the electrons are As indicated by portion 66, it flows in a vacuum from surface 64 of electrode 2 'to electrode 1 via tunneling or thermionic emission. When the electrons reach the electrode 1, they flow vertically through the silicon substrate as indicated by the arrow portion 65 and finally reach the foil backing 62 of the electrode 1. Next, the foil backing 62 of the electrode 1 is passed from left to right through a very low resistance path. The flow of electrons whose direction is indicated by the arrow 61 interacts with a magnetic field of a nearby permanent magnet not shown in FIG.

In this example, the total silicon thickness _ts is 0.5 millimeters or 0.25 millimeters per wafer, which is a standard thickness in the industry. The silicon material is doped to have a resistivity r _s of 0.02 ohm-cm, which is also a common practice. Young's modulus _{E s} of silicon are known to be 47 GPa clogging 4.7 × ^{10 10} Pascals. Silicon wafers are typically polished in the industry to a surface roughness of 0.5 nanometers, and a wafer with a lateral dimension of 1 centimeter achieves a surface flatness d _x of 1.0 micron.

  FIG. 7 shows the effect of silicon on the force compared to FIG. Since the gap is very narrow, the magnetostatic force is suppressed to 0.6 Newton. The resistance of silicon limits the current, and thus the magnetostatic repulsion. Also, if the gap is very narrow, there will be a drop in silicon at all supply voltages and zero voltage will appear in the gap, which means that the electrostatic attraction is zero at very narrow gap intervals.

To represent these effects quantitatively, consider the maximum current flowing in the system, which is the supply voltage V divided by the silicon resistance and equal to r _s t _s / Lw. With the applied voltage, electrode length and width of Example 1, the maximum current is about 50 amps in the presence of silicon. Furthermore, when the current approaches this 50 ampere level, the supply voltage is all reduced by silicon, and no voltage difference is obtained at the opposing surfaces of the electrodes.

  The restoring differential power in FIG. 7 is relatively large. According to the figure, a 0.1 nanometer difference from the desired separation produces a restoring force exceeding 0.05 Newton. As will be calculated, this restoring force is much greater than the bending force required to flatten the electrode 1 and much greater than the bending force required to achieve a parallel state with the electrode 2.

To flatten the 1 micron waveform of electrode 1, a force of 40 d _x E _s wt _s ³ / 12L ³ is required. This force is calculated to be 0.003 Newton. If electrode 1 and electrode 2 have opposing waveforms, the required force is twice this amount, or 0.006 newtons, to maintain the gap within 0.1 nanometer of the desired gap. Much less than the 0.05 Newton resilience available.

  For the following reasons, the force feature of FIG. 7 with silicon electrode material is more desirable than that of FIG. 6 with metal foil material. (1) The force in the presence of silicon is not so great as to generate vibrations or sudden movements that can damage or destabilize the system as in the case of pure metal electrodes. (2) Since the flatness of the silicon wafer is higher than that of the metal foil, the system can be started closer to the desired operating point. (3) The resistance of silicon prevents the generation of a large amount of current in a narrow local range that results in high temperature and evaporation damage to the electrode material. (4) The rigidity of silicon reduces the amount of material movement, maintains the gap for a long time, and reduces the risk of fatigue, cracking and deformation. (5) The high rigidity and flatness of the silicon ensures that the gap is maintained even in the presence of local variations, reducing the exponential shape, uniformity of electrode thickness, and accuracy of other parameter variations in materials and design No longer need it.

  FIG. 9a shows another example of how this device can be used in the case of another type of energy conversion called thermophotovoltaic. In this example, the heat source 71 emits a light beam, indicated by 72, to the photosensitive material 75 across a gap 74 that is narrower than the wavelength of the light beam, and the photosensitive material is indicated by an arrow 76. Generate current. In this example, the photoelectron emitting material 73 may be tungsten or the like. Photosensitive material 75 may be silicon, selenium, gallium, arsenic, indium, or combinations or alloys thereof. The required length of the gap 74 is generally shorter than the minimum wavelength emitted by the photoemission material 73 to achieve near-field optical conditions, i.e. about 100 nanometers. In this case, the photoelectron emission electrode 73 is rigid and flat, and the gap side is polished. The photosensitive electrode 75 is sufficiently flexible to be planarized to form a very uniform gap of about 100 nanometers.

  FIG. 9b shows a graph of the force that can form a stable gap in the thermophotovoltaic implementation of the present invention. At these distances, the electrostatic force is very small and unimportant, so a spring force or similar external force may be substituted for this to create an attractive force between the two electrodes. The spring force has a linear magnitude correlated with the gap separation. The repulsive force that keeps the balance is generated as in the previous example by the current drawn by the arrow 76 flowing in the presence of a magnetic field not shown in FIG. This current is generated by the photosensitive material that receives the photons emitted from the electrode 73, otherwise it acts to provide and maintain a uniform gap separation as described in the previous example. The repulsive force 46 ′ in FIG. 9 b is proportional to the thermophotovoltaic current, and its action and separation state are derived from Non-Patent Document 5 described above.

  FIGS. 10a-10c show how the design of FIG. 8 or FIG. 9 is assembled, with a number of devices connected electrically in series and thermally in parallel. In addition, FIGS. 10a-10c show how many of these devices can be scaled up using manufacturing techniques widely used in the semiconductor industry. FIG. 10a shows a base substrate 82 that holds one side of a number of devices. This substrate 82 is cooled when the device operates as a thermal tunnel cooler, or heated when operating as a thermo-electric converter, and emits when the device operates as a thermo-photovoltaic converter. FIG. 10 b shows a side view of a film stack formed to produce a number of devices on the substrate 82. The substrate 82 is made of silicon, silicon carbide, aluminum, gallium arsenide, or similar substrate materials commonly used in the industry. Layer 88 is an oxide or similar film that electrically insulates first metal layer 83 from substrate layer 82 but is capable of conducting heat. The first metal layer 83 is a relatively thick layer with high conductivity to conduct current for thermal tunneling operation or to conduct heat for thermophotovoltaic operation. Layer 83 may be, for example, copper or a less expensive metal such as aluminum. The gap layer 84 is a metal or other film that is most suitable for the boundary with the gap. In the case of a thermal tunnel, gold is an inert metal, so this layer 84 is gold to protect it from oxidation and contamination. In the case of thermophotovoltaic operation, the gap layer 84 may be tungsten or other material with high photoemission so that heat is maximally converted into photons that traverse the gap. The layer 85 is a sacrificial layer that is removed after the film stack of the layers 83, 84, 84 ', and 83' is formed. The sacrificial layer provides an additional film including the second electrode in the structure. After removing the sacrificial layer 85, a gap is formed between layers 84 and 84 'due to the force balance of FIGS. 5, 6, 7 and 9b described above. Layer 84 'receives energy from the gap and is optimized to protect layer 83' from contamination or oxidation. In the case of thermal tunneling, layer 84 'may be made of gold. For thermophotovoltaic operation, layer 84 'may be a photosensitive material described as material 75 in Figure 9a. Layer 83 'is an energizing layer that carries current from the device, and its material may be copper or aluminum. When the film stack shown in FIG. 10b is formed using semiconductor processing, a series electrical connection is made as seen in FIG. 10c. In this case, electrical connections are made from the top electrode to the adjacent substrate electrode using wires and wire bonds 86. Wire 89 provides electrical input and output to a number of devices. The sacrificial layer 85 may be made of a material that is removed using a processing liquid, gas, or by dissolving or evaporating with heat.

  Once a pair of devices are formed as shown in FIGS. 8, 9a, 10c, they can be inserted into a heat exchanger package, for example as shown in FIG. 11a. Here, the electrode pair or array 92 of electrode pairs transfers heat from one fin 93 to a corresponding fin 93 '. All the fins 93 are physically connected to the first hot plate 90, and all the corresponding fins 93 'are physically connected to the second hot plate 90'. By assembling a small high temperature side 93 and a small low temperature side 93 ', the hot plates 90, 90' become a high temperature side and a low temperature side for thermal tunnel or thermophotovoltaic operation. The hot plates 90 and 90 'are manufactured from a material having high thermal conductivity such as copper, aluminum or silicon. The rectangular tube 91 becomes the wall of the sealed container and is made of a material having low thermal conductivity such as glass, Teflon (registered trademark), polyimide, or a similar material having sufficient compressive strength. If the thermal conductivity is low, the hot and cold plates 90, 90 'can be insulated to increase the effectiveness of the system. If the plates 90, 90 'have thermal expansion characteristics that are not compatible with the tube wall 91, soft vacuum compatible rubber, such as Viton, Teflon, polyimide, or such a type of seal in the industry The boundary material 95 may be fabricated from similar materials used to fabricate O-rings. When the thermal expansion characteristics of the hot plate materials 90, 90 'and the tube wall material 91 are substantially equal, the boundary material 95 may be a hard joint material such as glass frit, epoxy, solder, or welding. FIG. 11b shows how to build a magnet structure that surrounds the heat exchanger package 11a and supplies the magnetic field necessary to form a gap in the electrode pair 92 of FIG. 11a. Permanent magnet 101 is fixed in a rectangular ring of magnetically permeable material 100. Permanent magnet 101 may be fabricated from standard materials used for magnets, such as iron, cobalt, nickel, neodymium, boron, and aluminum alloys. Generally, the alloy is sintered into fine particles and then consolidated with a binder into the desired shape to achieve high remanence when magnetized. In order to maximize the magnetic permeability and magnetic field obtained by the permanent magnet 101, the rectangular ring 100 is made of the same steel used in the transformer. Such material may be iron-rich steel, or other alloys such as iron, cobalt, nickel, chromium, platinum.

  FIG. 13 shows how the magnet assembly is scaled up to accommodate an array of heat exchangers. The magnetically permeable material 110 is configured in a lattice structure with an array of voids for inserting the devices found in FIGS. 8, 9a, 10c, 11a. When the permanent magnet 101 is inserted into each cell, a magnetic field is generated between the magnets.

  In a microfabrication process, the magnet array of FIG. 13 may be constructed on top of the substrate of FIG. 10c, and the electrode pairs of FIG. 10c may be configured to be received in the air gap of the magnet array of FIG. In this case, the permanent magnet 101 and the transparent material are directly formed on the substrate similar to the structure of the electrode film in FIG. 10b directly as a metal film using a standard process such as vapor deposition, sputtering, or plating. 110 may be grown.

  FIG. 14 shows additional electrical circuitry that may be required when the device of FIGS. 8, 10c, 11a operates as a thermal to electrical thermal tunnel converter. In the device 120 of the present invention, since a current needs to flow in order to form the gap, there is no gap before the current flows. In FIG. 14, the external power supply 122 supplies the current used to form a gap in the device 120. When a gap is formed and heat is applied to one electrode, a temperature difference is generated with respect to the other electrode. When this temperature difference exists, the thermal tunnel current of hot electrons begins to flow, generating an additional current. When the thermal tunnel current flows, as described above, the gap of the device 120 can be maintained by itself. At this time, the external power source 122 is no longer necessary and is disconnected by the switch 123. Thus, the circuit of FIG. 14 is a starting circuit for heat tunneling the heat to a power source for the electrical load 126. Whenever the heat source is removed and then repositioned, the switch 123 can turn on the external power source 122 again.

  FIG. 12a shows another example of housing the electrodes of the device, similar to how a microelectromechanical system (MEM) is housed when a vacuum environment is needed. The upper and lower hot plates 130 are made of silicon and cut from a standard silicon wafer. Silicon has high thermal conductivity and is therefore well suited for the thermal path of this device. The walls of the package 132 are made of glass with a low thermal conductivity but a thermal expansion coefficient close to that of the silicon heat plate 130. Since glass and silicon have similar thermal expansion characteristics, it is possible to use a known glass frit bonding method between 130 and 131. Glass frit bonding is commonly used to bond two pieces of glass together, but naturally a glass silicon dioxide layer is formed on the silicon surface exposed to air, so that the glass is bonded to silicon. Can also be used for joining. As a result, a very hard and hermetic seal is formed between the glass and silicon that can easily withstand vacuum pressures. In the MEM industry, similar vacuum packages are used for accelerometers, oscillators, and high frequency switches. The pedestal layer 131 is also made of silicon and may be bonded to the heat plate 134. The metal layer 134 on the upper and lower hot plates 130 is used to make electrical connections to the electrodes inside the package without the need for through holes or other mechanisms that limit the life of bulbs and other vacuum products.

  FIG. 12b shows how electrodes are provided in the vacuum package of FIG. 12a. The electrode pair 145 corresponds to FIGS. 8, 9a and 10c. The thermal boundary material 141 provides a soft layer that conducts heat between each electrode and the outside of the package, allowing the electrodes to move during operation. Examples of thermal boundary materials 141 include Bergquist Corporation gap pads, Apiezon or Dow Chemical vacuum grease, MER Corporation carbon nanotube composites and mixtures, or other soft materials mixed with thermally conductive particles. Bonding material 143 bonds the glass walls to the silicon hot plate, examples of which include epoxy and glass frit. A wire 144 connects the base of the electrode to the upper and lower plates. Examples of wire materials include flat foil or cylindrical wire made of copper, aluminum, or other conductive material. The copper layer 134 allows a current to flow widely throughout the resistive silicon plate 130. The silicon plate is doped with boron, arsenic, or similar elements to increase conductivity and minimize resistance loss of current to the package. The getter filament 140 becomes hot when a voltage is applied to the copper pad 134, just like the filament in the bulb. A suitable material, such as cesium chromate, coats the filament 140 and releases cesium vapor into the vacuum package. Cesium vapor, once released, performs the following functions: (1) By reacting with air and other gases remaining in the package to produce solids, these air and gases are discharged after sealing. (2) A similar reaction removes gas leaking into the chamber throughout the life of the device. (3) By naturally forming a cesium single layer or a sub-single layer on the gap facing surface of the electrode 145, a low work function layer is generated to assist electron emission in the gap.

  Other Embodiments The basic example above shows how a functional thermal tunnel system is designed to achieve cooling or power conversion. Other examples can be easily designed by changing one or more of the parameters used in Examples 1 and 2. The gap distance can be increased by one or more of the following changes. (1) increase in magnetic field, (2) decrease in voltage, (3) increase in current, (4) increase in length of the flexible electrode, (5) decrease in area of the flexible electrode. By making the opposite change, the gap distance can be reduced.

  It should be noted that some of the features described above are not necessary or can be achieved without increasing manufacturing complexity. Functional thermal tunnel converters larger than the nanometer dimension are not produced in the industry, so the actual behavior at large scale is unknown. For example, referring again to FIGS. 1a-1b, the low work function layer 5 may not be necessary if the gap is slightly small. Depending on the surface roughness after polishing, it may be possible to easily provide the reinforcing material 5 ', thus naturally forming the top and valleys known to improve electron emission. Depending on the choice of resistive material for the electrodes 1, 2, the abutment tip 6 may also be unnecessary. The electrode patterning of FIG. 2a, which is also provided with a top and a valley to reduce electrostatic forces, may also be achieved by natural surface roughness after polishing. Finally, if the tunnel process has been experimentally demonstrated in an air gap, the vacuum chamber 20 may not be necessary. In addition, the exponential shape of the electrode 1 can be approximated by a triangle that is easier to manufacture. These complex features (tip 6, layer 5, reinforcing material 5 ′, patterning in FIG. 2a, curved shape of electrode 1, vacuum chamber 20) all explain what may be required in the final production. It is included in this disclosure for completeness above.

  The devices disclosed herein are useful in manufacturing various types of electronic junctions in the electronics industry that require a uniform gap between the electrodes. For example, the present disclosure can be applied to a thermoelectric device that has insufficient heat insulation between the high temperature side and the low temperature side. Since the vacuum spacing over the thermoelectric stack provides better thermal insulation, the present disclosure provides a means of providing this gap independent of or in combination with thermionic or thermal tunneling methods.

  The final comment on the ease of manufacturing of the device disclosed here relates to an explanation of other natural forces that occur when two very smooth surfaces are brought close together. Two attractive forces known to bring smooth surfaces close together are the Kashmir force and the Van der Waals force. These forces are strong enough to bring the two electrodes of the present invention into close proximity before applying a voltage, but during operation of the present invention, the desired interaction between electrostatic and magnetostatic forces as described is desired. It is not expected to be powerful enough to affect action and superiority. However, these Kashmir and van der Waals forces ensure that the two electrodes are in full surface contact before operating the device with the applied voltage. In this case, the operation of the present invention only requires that the two electrodes be separated by a few nanometers. These Kashmir and van der Waals forces also help to avoid the need for the insulating layer 4 of FIG. 1 and further simplify the design of the present invention.

  Multiple units of the device can be connected in parallel and in series to achieve a high level of energy conversion or to match the voltage with the power source, or both.

  (Results of Experiment and Simulation) The electrode configuration of FIG. 8 was assembled in a microelectronics laboratory using copper as the foil backing, and this electrode pair was placed inside the magnet structure as shown in FIG. 11b. . In order to generate a voltage proportional to the temperature, a thermocouple was attached to each electrode, and the entire apparatus was placed in a vacuum chamber pumped to a vacuum pressure of 1E-3 Torr. When the electrode pair was activated by an external power supply of 1.1 amperes, a relative temperature difference of 3.0 degrees was observed between the two electrodes, and the low temperature side was the side emitting electrons. It was observed that this same relative temperature difference was removed when any of the following operations were performed. (1) replacing the vacuum with atmospheric nitrogen, (2) deactivating the chip by turning off the external power supply, and (3) current to increase the constant attractive force between the electrodes instead of forming a gap. To reverse. It is estimated that each of these three actions has removed the thermal tunneling effect. Not only the electrical properties observed for the electrodes, but also the computer simulation of the electromechanical system of this device was consistent with this design that well forms the thermal tunneling gap.

  It is emphasized that the device and process embodiments described above, and in particular the “preferred” embodiments, are merely possible implementations and are presented merely for a clear understanding of the principles of the invention. Keep it. Various embodiments of the self-positioning electrodes described herein can be designed and / or fabricated without departing from the spirit and scope of the invention. All such variations and modifications are intended to be included within the scope of this disclosure and protected by the following claims. Accordingly, the scope of the invention is not limited except as supported in the appended claims.

1 illustrates one example of a self-positioning electrode device of the present disclosure. The direction state of the electric current of the device of FIG. 1, a magnetic field, and a magnetostatic force is shown. 2 shows an alternative embodiment of the electrode 2 of the device of FIG. It is a schematic top view of the electrode 1 of the device of FIG. FIG. 3 is a bottom perspective view showing a cut portion of the embodiment of the electrode of FIG. 2. 2 shows an alternative embodiment of the device of FIG. Fig. 4 shows yet another embodiment of the device of Fig. 1; It is a graph which shows qualitatively the interaction force in the device of FIGS. 5 is a graph showing quantitatively the interaction force in the device of FIGS. 5 is a graph showing quantitatively the interaction force in the devices of FIGS. 2 is a diagram illustrating a method of manufacturing an electrode from a silicon wafer material. Figure 4 shows an alternative embodiment with a wide gap suitable for thermophotovoltaic applications. Fig. 9 is a graph similar to Fig. 5 showing the interaction force in the device of Fig. 9a. FIG. 9 illustrates a method for mass production in which the multiple electrode pairs of FIG. 8 are assembled simultaneously using processing techniques common in the semiconductor industry. FIG. 9 illustrates a method for mass production in which the multiple electrode pairs of FIG. 8 are assembled simultaneously using processing techniques common in the semiconductor industry. FIG. 9 illustrates a method for mass production in which the multiple electrode pairs of FIG. 8 are assembled simultaneously using processing techniques common in the semiconductor industry. FIG. 9 shows how the multiple electrode pairs of FIGS. 8, 9a and 10c are housed in a large heat exchanger to achieve high density and high capacity device functions. FIG. 9 shows how the multiple electrode pairs of FIGS. 8, 9a and 10c are housed in a large heat exchanger to achieve high density and high capacity device functions. FIG. 9 illustrates the electrode pair of FIG. 8 being stowed using a silicon glass frit vacuum seal and other standard microelectromechanical (MEM) packaging techniques common in the industry. FIG. 9 illustrates the electrode pair of FIG. 8 being stowed using a silicon glass frit vacuum seal and other standard microelectromechanical (MEM) packaging techniques common in the industry. Fig. 13 shows an array of permanent magnets mounted on a magnetically permeable grid to produce a large device from the small device of Fig. 8, 9a, 10c, 11a or 12b. FIG. 9 shows an example of a starting electronic circuit that can be used to form a gap in the device of FIG. 8, 10c, 11a or 12b before applying thermal energy in an embodiment where electricity is generated.

Claims (75)

  A device comprising a counter electrode or electrode assembly, wherein the repulsive force is equal and opposite to the attractive force distribution in the electrode or electrode assembly generated by the current distribution in the electrode or electrode assembly in the presence of an applied magnetic field distribution A device in which the distribution acts simultaneously to establish a stable and equilibrium separation at the opposing faces of the two electrodes.   The device of claim 1, wherein one or both of the counter electrodes are flexible.   The device of claim 2, wherein the flexible electrode comprises a substrate selected from the group consisting of a conductive metal, a layered metal / glass, a layered metal / plastic composite, and a semiconductor material.   Conductivity selected from the group consisting of silicon, germanium or gallium arsenide, optionally glass, polyimide, polyester, polyamide, polyacryl, or gold, silver, aluminum, copper and nickel combined in layers with polyolefins The device of claim 3, wherein the substrate comprises a metal.   The surface of the one or more electrodes is a low work function material, a thermoelectric sensing material, a plurality of peaks and valleys, a semiconductor resonator, a layered material having a resistive lower layer and a lower work function upper layer, and combinations thereof The device of claim 1, wherein the device is fabricated, coated, or deposited.   6. The device of claim 5, wherein the low work function material comprises layered alkali metals, alkali metal alloys, oxides, diamonds, nanotubes, or other combinations.   The low work function material includes cesium, sodium, potassium, thorium, metal-coated oxide, diamond film, silicon, germanium, an array of carbon nanotubes, and a collection of nanometer-dimensional oxide particles. The device of claim 6, wherein the device is selected from the group consisting of:   The device of claim 1 further comprising a permanent magnet attached to any electrode or in the vicinity of the electrode.   9. The device of claim 8, wherein the permanent magnet is provided on or is part of one of the counter electrodes.   9. The device of claim 8, wherein the permanent magnet comprises a conductive, ferromagnetic magnetic material of any combination of iron, cobalt, nickel, neodymium, and aluminum.   9. The device of claim 8, wherein one of the electrodes is formed of a permanent magnet having a non-conductive, ferromagnetic material coated with a conductive material.   The device of claim 1, further comprising mechanical, magnetic, electrostatic, electromechanical, or electromagnetically generated forces that compensate for excess or deficiency in magnitude of the magnetic attraction and repulsion.   The device of claim 1, further comprising a damping system to prevent vibration of the electrode about the equilibrium abutment position of either electrode.   The flexible electrode has a shape that generates a current density distribution that generates a desired repulsive force distribution between the electrodes or a repulsive force distribution equal to an attractive force distribution in the vicinity thereof in combination with a magnetic field distribution. Item 2. The device according to item 2.   The device of claim 14, wherein the width of the surface of the flexible electrode increases exponentially from one end to the other.   The device of claim 1, wherein the one or more electrodes are patterned or roughened with raised and non-raised areas to simultaneously reduce electrostatic forces and electrode resistance losses.   The device of claim 2, wherein the flexible electrode is wide at one end, and the wide end is secured to a support structure.   The device of claim 2, wherein the flexible electrode is narrowed at one end and the narrow end abuts the insulating support while the device is deactivated.   The device of claim 1, wherein a portion of the one electrode has a coating of non-conductive material, and another electrode abuts the coating while the device is deactivated.   The device of claim 2, wherein the flexible electrode comprises a metal foil attached to a flexible plastic membrane.   The device of claim 1, wherein the electrode is enclosed in a vacuum chamber.   The device of claim 1, wherein the electrode is enclosed in a chamber filled with an inert gas.   24. The device of claim 22, wherein the inert gas comprises argon or nitrogen.   The device of claim 2, wherein the strength of the magnetic field varies inversely with the current density of the flexible electrode to achieve a constant force.   The device of claim 1, wherein one of the counter electrodes is formed in a spiral shape and a magnetic field extends radially from the center of the device.   26. The device of claim 25, wherein the helical shape is linear and increases in width.   26. The device of claim 25, wherein the helical shape is exponentially increasing in width.   The device of claim 1, further comprising a heat source connected to the electrode.   The device of claim 1, further comprising a power source connected to the electrode.   Providing the device of claim 1 and adjusting the strength of the magnetic field and current distribution to place the counter electrode in a stable, spaced, balanced position, or for converting thermal energy into current, or A process for converting electrical energy into refrigeration.   32. The process of claim 30, wherein the counter electrodes are spaced apart in a range of about 20 nanometers or less.   31. The process of claim 30, wherein the strength of the magnetic field and the current distribution is adjusted so that the counter electrode is placed in stable, spaced and balanced positions separated by a range of 1 nanometer to 20 nanometers.   31. The process of claim 30, wherein the intensity is adjusted to provide an electrode spacing in the range of 6 nanometers to 20 nanometers.   31. The process of claim 30, wherein the intensity is adjusted to provide an electrode spacing in the range of 1-6 nanometers.   A process for converting heat into cooling or electrical energy using the device of claim 1.   36. The process of claim 35, wherein the heat source is a radiation source, heat from the environment, geothermal energy, heat generated from an engine or animal metabolism.   36. The process of claim 35, wherein the heat source is a human organism.   36. The process of claim 35, wherein the heat source is a human organism and the device is a handheld device.   36. The process of claim 35, wherein the heat source is an operating electric / steam / internal combustion engine, burning fuel, exhaust gas thereof.   36. The process of claim 35, wherein the heat source is an internal combustion engine or exhaust gas thereof and the device is incorporated into the engine or gas exhaust pipe as a heat sink.   The device of claim 1, wherein the magnetic field strength decreases in the same direction as the current density decreases at one or both electrodes to achieve a uniform force distribution acting between the electrodes.   42. The device of claim 41, wherein the proximity of the magnetic material decreases in the direction of increasing current density at one or both electrodes.   The device of claim 1, wherein the electrodes are comprised of multiple periodically spaced layers.   A device comprising multiple units of the device of claim 1 assembled in series.   A device comprising multiple units of the device of claim 1 assembled in parallel.   A device comprising multiple units of the device of claim 1 assembled in parallel and in series.   36. The process of claim 35, operating at a naturally occurring temperature.   36. The process of claim 35, wherein the device is used in a refrigeration apparatus, an air conditioner, a cooling blanket, a cooling garment, a cooling apparatus attached to or provided on a human or animal body.   A device comprising a multi-device of the device of claim 1 fabricated on a wafer or wafer stack to achieve production efficiency, packaging density or a combination of production efficiency and packaging density.   50. The device of any of claims 43 to 46 and 49, wherein the electrodes are disposed on a small heat sink that is all connected to a large heat sink that accumulates heat flow to or from the multi-device.   51. The device of claim 50, wherein the small heat sink includes fins that extend in a different planar direction than the large heat sink and are connected to the large heat sink.   44. A plurality of permanent magnets and transparent and ferromagnetic materials configured to have air gaps with magnetic fields that form gaps in the individual devices when current is passed through the devices. One of the devices 46, 49, 50, and 51.   The permanent magnets are arranged inside a grid formed of a permeable magnetic material so as to form an array of devices comprising a side for injecting heat into the array and a side for extracting heat from the array. 53. The device of claim 52.   54. A device according to any one of claims 1, 43 to 46, 49 to 53, produced by micro electro mechanical system (MEM) processing and design techniques.   55. The device of claim 54, wherein one or both of the electrodes are formed from an array of cantilever structures fabricated from a combination of film growth and sacrificial layer removal on an industry standard substrate.   53. The device of claim 52, wherein the permanent magnet and / or transmissive magnetic material is one of iron, cobalt, nickel, chromium, platinum, aluminum, neodymium, alloys thereof, or recombination sintered materials thereof.   2. The device of claim 1, further comprising an electrical circuit that causes the device to generate a gap formation start current that provides a separation that maintains a temperature difference between the two electrodes or electrode assemblies until an electron tunneling current is generated as the gap formation current. .   A low work function layer is formed by including cesium or barium or a combination of cesium and barium in a vacuum package that generates vapor that forms a single layer, sub-single layer, or multiple single layers on one or both of the counter electrodes. The device of claim 1.   57. A device according to any one of claims 1 and 49 to 56, comprising a material that acts as a getter to remove unwanted gases after production.   60. The device of claim 59, wherein the getter material is selected from the group consisting of titanium, cesium, barium, sodium, potassium, and combinations thereof.   57. The device of claims 1 and 49 to 56, wherein the electrode or electrode assembly is provided in a evacuated vessel comprising two heat paths into and out of the vessel.   62. The device of claim 61, wherein the two thermal path separating material is glass, ceramic or other material with low thermal conductivity.   62. The device of claim 61, wherein the thermal path material is made of silicon, copper, aluminum, or other material with high thermal conductivity.   64. The device of claim 62 or 63, wherein the container walls are glass and the thermal path is silicon and they are joined using a glass frit process to form a vacuum seal.   65. A silicon material is highly doped so that electrical connections to the electrodes flow through the silicon to avoid the need for wire holes, feedthroughs, or similar connections to the interior of the vessel. Devices.   64. A soft heat transfer material with sufficient thermal conductivity is used to allow some movement of the electrode while simultaneously transferring heat to or from the electrode. 64 or 65 device.   68. The device of claim 66, wherein the heat transfer material is one of a liquid metal, a non-silicon polymer, a mixture comprising carbon nanotubes, a vacuum compatible grease or a suspension of thermally conductive particles in a soft or liquid material.   66. The device of any of claims 62, 63, 64, 65, wherein the connection wire to the electrode or electrode assembly is attached by solder, solder bumps, ultrasonic wire bonding, conductive epoxy, solder paste or contact pressure.   59. The device of claim 58, wherein an alkali metal composite is attached to the filament so that the alkali metal is present inside the container by heating, evaporation and condensation.   70. The device of claim 69, wherein the alkali metal is cesium and the complex is cesium chromate.   70. The device of claim 65 or 69, wherein the filament connector is electrically routed through the doped silicon heat transfer side to avoid the need for wire holes and feedthroughs.   70. The device of claim 69, wherein the filament is electrically connected in parallel with the device and is designed to open a circuit after the alkali metal has evaporated.   13. The device of claim 12, wherein the additional force results from a distribution of spring or sponge material.   A photosensitive material for use in radiant conversion of electrical power from a radiation electrode to the other photosensitive electrode, primarily by thermal tunneling of photons, generating an electrode spacing in the range of 20 nanometers to 1000 nanometers. 32. The process of claim 30, wherein the electrode comprises.   75. The process of claim 74, wherein the intensity provides an electrode spacing in the range of 20 nanometers to 100 nanometers.

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