Patent Publication Number: US-7582992-B2

Title: Electrical assemblies using molecular-scale electrically conductive and mechanically flexible beams and methods for application of same

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This is a divisional of U.S. patent application Ser. No. 10/453,326, filed Jun. 2, 2003, now U.S. Pat. No. 7,199,498 which is hereby incorporated by reference herein in its entirety. 
    
    
     BACKGROUND OF THE INVENTION 
     This invention relates to micrometer scale and nanometer-scale electromechanical assemblies and systems. In particular, the present invention relates to electromechanical assemblies based on suspended nanotubes or other molecular-scale electrically conductive and mechanically flexible wires. These assemblies may be used in a variety of systems for applications, such as motors, generators, pumps, fans, compressors, propulsion systems, transmitters, receivers, heat engines, heat pumps, magnetic field sensors, magnetic field generators, inertial energy storage and acoustic energy conversion. 
     Molecular wires, such as carbon nanotubes, can now be assembled and grown into structures. However, current nanometer and micrometer structures provide limited functionality. It is therefore desirable to provide nanometer-scale and micrometer scale electromechanical structures that can utilized in a wide variety of applications. 
     As the use of electronic devices continues to flourish, there is an ever increasing need to provide more efficient and/or quieter ways to cool the components that are typically the heart of such devices. For example, most personal computers include one or more fans that are required to maintain the temperature of the microprocessor within a certain operational range. These fans are often noisy, and often result in large quantities of dirty air being pulled through the computer from the air intakes. 
     Furthermore, conventional vacuum pumps and heat engines generally have a large number of moving parts that wear with use. These vacuum pumps and heat engines are also fabricated on the meter to micro-meter scale. It is therefore desirable to provide low wear pumps and engines that can be fabricated on the nanometer-scale. 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention to provide molecular structures that can be utilized as, for example, motors, generators, pumps, fans, compressors, propulsion systems, transmitters, receivers, heat engines, heat pumps, magnetic field sensors, magnetic field generators, inertial energy storage and acoustic energy conversion. 
     The nanometer-scale assemblies of the present invention preferably utilize suspended nanotubes, or nano-wires, such as tubular carbon fullerenes, as an electromechanical element. These suspended nanotubes may be attached at both ends, similar to a transmission line or jump-rope, or they may be attached at one end only, like a cantilevered rod. These nanotubes can be coupled electromagnetically by suspending them in a magnetic field. As a result, electrical currents in the nanotube may interact with the magnetic field. Alternately, these nanotubes can be coupled electrostatically by suspending them near conductive surfaces, plates or pads. Thus, electrical charges on the nanotube may interact with charges present on nearby conductive surfaces through electrostatic forces. 
     An electromagnetically coupled assembly may include a nanotube which is suspended at both ends and immersed in a magnetic field. The nanotube may be grown or assembled such that the nanotube is suspended between two electrical connections. By applying a pulsed DC or AC current through the nanotube, the suspended nanotube can be caused to oscillate like a jumprope, spinning around a line drawn between two anchor locations at the two electrical connections. The motion of the nanotube can be used as mechanical energy for a variety of applications. Conversely, a moving suspended nanotube immersed in a magnetic field will generate currents in the nanotube, which can be collected and utilized by electronic circuits attached to said nanotube. 
     An electrostatically coupled assembly may include a nanotube that is suspended near one or more plates, pads or surfaces, where these surfaces are electrically isolated from said nanotube. The nanotube may be included in the assembly, for example, such that the nanotube is suspended between two electrical connections or attached at one end only to an electrical connection. By applying appropriate voltages to the nearby plates and the nanotube, electrostatic forces can be applied to the nanotube. In this manner, the suspended nanotube which is attached on both ends can be caused to oscillate like a jumprope, spinning around a line drawn between two anchor locations at the two electrical connections. A nanotube which is attached at one end only can be caused to whip in a spinning motion around the line normal to the connection point. The motion of this nanotube can be used as mechanical energy for a variety of applications. Conversely, a moving nanotube will generate voltage fluctuations in the nearby plates because of changes in the capacitive coupling, which can be utilized and collected by electronic circuitry. 
     The nanometer-scale electromechanical assemblies of the present invention may be constructed to convert electrical energy into mechanical energy, such that the mechanical energy can be applied at a molecular scale. This mechanical energy can be used to drive molecules in a fluid, such as a liquid or gas, to provide a molecular scale pump, fan, compressor or propulsion system. Further, a plurality or array of these assemblies may be used to affect said fluid at a macroscopic level, in systems such as cooling fans, pumps, compressors or propulsion devices. These systems can be incorporated as components of larger systems, such as a compressor in a heat engine. Alternatively, said nanotube assemblies may be used as a motor, in which said mechanical energy is used to directly impart motion to other molecules which are part of a larger microelectromechanical (MEM) device. 
     The nanometer-scale electromechanical assemblies of the present invention may be constructed to convert mechanical energy to electrical energy, such that said electrical energy may be used for other purposes. This electrical energy can be generated using the mechanical energy supplied by the motion of molecules in a fluid, such as a liquid or gas, to provide a molecular scale turbine generator, wind generator or heat pump. Further, a plurality or array of these assemblies may be used to provide electrical energy at a macroscopic scale. These systems can be incorporated as components of larger systems, such as a turbo-generator in a heat engine. Alternatively, said nanotube assemblies may be coupled to other molecules in a larger microelectromechanical (MEM) device, such that it can be used as a generator or alternator driven by the motion of molecules in said MEM device. 
     The nanometer-scale assemblies may be arranged within a chamber and utilized to control the flow of a working substance, such as a gas or other fluid, down a desired path through the chamber. The current applied to the nanotubes, or the timing of charges applied to plates, may be reversed to change the direction of the spinning nanotube and, as a result, pull the working substance in the opposite direction. The nanotube assemblies may include an array of transistors that are utilized in routing the current to the nanotubes for electromagnetically coupled assemblies, or are utilized in routing the application of voltage to nearby plates for electrostatically coupled assemblies. 
     Each of the nanotubes may be mounted within a trough such that half of the circumference of rotation of the nanotube occurs within the trough and half within the chamber. This provides an efficient mechanism for the working fluid to be smoothly transported from one side to the other. This type of assembly may be used in a variety of different applications, such as, for example, a vacuum pump, cooling fan, compressor, propulsion system, or any other device that benefits from moving a working substance in a desired direction. 
     Other applications of assemblies of the present invention may include, for example, a nanometer-scale jet engine for propulsion applications or a nanometer-scale heat engine for power conversion. In such a system, a central chamber would be used in conjunction with multiple nanotube assemblies. One or more of the nanotube assemblies may be included in a channel connected to the central chamber on one side, while a second set of nanotube assemblies is present in a channel connected to the central chamber at the other side. Gas, such as air, which may be used as the working substance, is compressed by action of the nanotube assemblies in the channel leading into the central chamber. Once there, the gas is heated by some thermal source and ejected into the other channel containing nanotube assemblies, with said second assembly of nanotubes acting as a turbine or expander. The nanotubes in the assembly that act as the input to the chamber act as motors or compressors, while the nanotubes in the expander assembly operate as generators or turbines, producing a net increase in power output due to the heat input into the central chamber, in the manner of a jet engine or a turbine power generator. 
     Assemblies of the present invention can also respond to changes in the electromagnetic conditions in the environment. Accordingly, it is a further object of the present invention to provide nanotube electromechanical assemblies that can be used as sensors for magnetic field or as antenna for sensing electromagnetic transmissions. 
     Assemblies of the present invention can also respond to changes in the mechanical conditions in the environment. Accordingly, it is a further object of the present invention to provide nanotube electromechanical assemblies that can generate electrical energy from the motion provided by ambient acoustic vibrations or ambient motion of other molecules in the environment, either through direct collision or other mechanical energy transmission means. 
     Assemblies of the present invention can create changes in the electromagnetic conditions in the environment. Accordingly, it is a further object of the present invention to provide nanotube electromechanical assemblies that can be used as magnetic field generators or as antenna for transmitting electromagnetic radiation. 
     Assemblies of the present invention can also store energy in the inertia of the molecular-scale wire, such as a flywheel would in a macroscale energy storage device. Accordingly, it is a further object of the present invention to provide nanotube electromechanical assemblies that can be used as inertial energy storage devices. These molecular flywheels, coupled either electromagnetically or electrostatically consistent with the above descriptions, can be either driven as a motor to increase the inertial energy storage or used as a generator to discharge said energy as electrical power. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above assemblies of the invention, and systems and constructs enabling methods for application of said invention, and advantages of the present invention shall be apparent upon consideration of the following description, taken in accordance with accompanying drawings, in which like reference characters refer to like parts throughout, and in which: 
         FIG. 1  is a perspective, partial-sectional view of a nanotube electromechanical system constructed in accordance with the present invention; 
         FIG. 2  is a perspective view of the portion of the nanotube electromechanical system of  FIG. 1  in which the upper surfaces have been removed to expose the individual nanotube assemblies; 
         FIG. 3  is a cross-sectional plan view of the portion of the nanotube electromechanical system of  FIGS. 1 and 2 , taken along the line  3 - 3 ; 
         FIG. 4  is a plan view of the nanotube electromechanical system of  FIGS. 1 and 2 , as viewed from the exit of the chamber; 
         FIG. 5  is a three-dimensional, perspective view of the underside of the nanotube electromechanical system of  FIGS. 1 and 2 , which shows possible control/driver electronics; 
         FIG. 6  is a schematic illustration of the layout of the control/driver electronics of  FIG. 5 ; 
         FIG. 7  is a perspective, partial sectional view of a portion of another nanotube electromechanical system constructed in accordance with the present invention; 
         FIG. 8  is a cross-sectional plan view of the portion of the nanotube electromechanical system of  FIG. 7 , taken along line  8 - 8 ; 
         FIG. 9  is a three-dimensional, perspective view of the underside of the nanotube electromechanical system of  FIG. 7 , which shows the control/driver electronics; 
         FIG. 10  is a schematic illustration of the layout of the control/driver electronics of  FIG. 9 ; 
         FIG. 11  is a perspective, partial-sectional view of a portion of another nanotube electromechanical system constructed in accordance with, the present invention; 
         FIG. 12  is a perspective view of the portion of the nanotube electromechanical system of  FIG. 11  in which a portion of the upper surfaces have been removed to expose the individual nanotube assemblies and circuitry; 
         FIG. 13  is a cross-sectional plan view of the portion of the nanotube electromechanical system of  FIGS. 11 and 12  taken along line  13 - 13 ; 
         FIG. 14  is a perspective view of a portion of another nanotube electromechanical system constructed in accordance with the present invention; 
         FIG. 15  is a cross-sectional plan view of the portion of the nanotube electromechanical system of  FIG. 14  taken along line  15 - 15 ; 
         FIG. 16  is a perspective view of a portion of another nanotube electromechanical system constructed in accordance with the present invention; 
         FIG. 17  is a schematic illustration of the layout of the control/driver electronics of  FIG. 16 ; 
         FIG. 18  is a cross-sectional plan view of the portion of the nanotube electromechanical system of  FIG. 16  taken along line  18 - 18 ; 
         FIG. 19  is a perspective view of a portion of another nanotube electromechanical system constructed in accordance with the present invention; 
         FIG. 20  is a cross-sectional plan view of the portion of the nanotube electromechanical system of  FIG. 19  taken along line  20 - 20 ; 
         FIG. 21  is a perspective view of a portion of another nanotube electromechanical system constructed in accordance with the present invention, viewed from above the system; 
         FIG. 22  is a perspective view of the portion of the nanotube electromechanical system of  FIG. 21 , viewed from below the system; 
         FIG. 23  is a cross-sectional plan view of the portion of the nanotube electromechanical system of  FIG. 21  taken along line  23 - 23 ; 
         FIG. 24  is a perspective view of a portion of another nanotube electromechanical system constructed in accordance with the present invention; 
         FIG. 25  is a cross-sectional plan view of the portion of the nanotube electromechanical system of  FIG. 24  taken along line  25 - 25 ; 
         FIG. 26  is a close-up perspective view of a portion of the nanotube electromechanical system of  FIG. 24  for illustrative purposes; 
         FIG. 27  is a perspective view of a portion of another nanotube electromechanical system constructed in accordance with the present invention; 
         FIG. 28  is a cross-sectional plan view of the portion of the nanotube electromechanical system of  FIG. 27  taken along line  27 - 27 ; 
         FIG. 29  is another cross-sectional plan view of the portion of the nanotube electromechanical system of  FIG. 27  taken along line  27 - 27 ; 
         FIG. 30  is another cross-sectional plan view of the portion of the nanotube electromechanical system of  FIG. 27  taken along line  27 - 27 ; 
         FIG. 31  is a perspective view of a portion of another nanotube electromechanical system constructed in accordance with the present invention; and 
         FIG. 32  is a perspective view of a portion of another nanotube electromechanical system constructed in accordance with the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE DRAWINGS 
       FIG. 1  shows a portion of a nanotube electromechanical assembly  100  constructed in accordance with the principles of the present invention. The portion shown in  FIG. 1  includes a lower substrate base  102 , channel side walls  104  and  106 , permanent magnet  108 , upper substrate  110  and six nanotube assemblies  112 . Also shown in  FIG. 1  are illustrations of molecules  114  that represent molecules of the working substance in which assembly  100  is immersed, as well as indicators  116  that show the path of molecules  114  through the channel side walls  104  and  106 . 
     Each of the electromagnetically coupled nanotube assemblies  112  of the present invention includes several components that may be more readily appreciated from  FIG. 2 .  FIG. 2  shows nanometer-scale assembly  100  of  FIG. 1 , except that upper substrate  110  and permanent magnet  108  have been removed. Each of nanotube assemblies  112  is formed from a nanotube  120 , a pair of electrically conductive pads  122  and  124 , and a trough  126 . For clarity, only one of the six nanotube assemblies of  FIG. 2  is labeled, however the description applies to each of them equally. Pads  122  and  124  are mounted to lower substrate  102 , which is electrically insulating. 
     The nanotube assemblies  112  of this invention may be arranged within the chamber in any manner for application in this system or other systems consistent with this invention. It may, however, be preferable to arrange the assemblies  112  in a staggered fashion, such as shown in  FIG. 2 , to increase the likelihood that molecules of the working substance (such as a gas, liquid or other fluid) are forced to travel from one end of the channel to the other. The advantage of this configuration is readily apparent from  FIG. 4 , which shows how the staggered configuration provides at least 60% coverage of the channel. Such a configuration would therefore necessarily increase the overall efficiency of the device in many applications. Thus, if the device were configured as either as a pump or as a generator, more energy would be transferred between the nanotubes and the working fluid with the staggered configuration than if the troughs  126  were in alignment with each other. 
     The ends of each nanotube  120  are mounted, respectively, to one of the pads  122  and  124 . It may be preferable to include some slack in nanotube  120  so that it hangs like a jump rope (see, for example,  FIGS. 1-4 ). Alternatively, it may be preferable to mount nanotube  120  across pads  122  and  124  such that there is some tension between pads  122  and  124 , in which case, the device would take advantage of the vibration of the nanotube rather than the rotation, or would take advantage of a smaller rotational amplitude at a higher frequency than a nanotube with lower tension. Alternatively, it may be preferable to mount nanotube  120  across pads  122  and  124  such that one or more of said pads is on a flexible member, in which case, the ends of the nanotube would become drawn closer together as the tension in the nanotube is increased at high rotational speeds; thereby allowing higher amplitudes and higher energies that one could obtain using a nanotube which was mounted with no slack to rigidly positioned pads. 
     Each of nanotubes  120  may, for example, be constructed of a material such as carbon; an example being a single walled carbon nanotube (a tubular fullerene) having a diameter of approximately 1 to 20 nanometers and a length from 20 to hundreds of nanometers (persons skilled in the art will appreciate that the dimensions of nanotubes  120  may be varied without departing from the spirit of the present invention). One advantage using single walled carbon nanotubes for nanotubes  120  is that they are formed of a single molecule, therefore, they may be bent endlessly at will within dimensional limits without damaging them, and without losing a lot of energy to friction. A further advantage of using single walled carbon nanotubes for nanotubes  120  is that the tensile strength is very high, allowing high vibrational and rotational energies. Another further advantage of using single walled carbon nanotubes for nanotubes  120  is the high electrical conductivity of these nanotubes. Alternatively, each of members  120  may be another suitable structure which is not a single molecule, such as, but not limited to, a carbon filament, a multiwalled carbon nanotube, or simply an electrically conductive, flexible piece of wire. Alternatively, the nanotube may be any of many other suitable molecular structures, including, but not limited to, tubular boron carbide molecules, tubular carbon nitride molecules or a single crystal filament such as quartz. In addition, it may be preferable to bond other molecular structures at one or more points along the primary nanotube or molecular wire to increase the mass or the cross-sectional size of the rotating element. 
       FIG. 3  shows a cross-sectional plan view of assembly  100  taken along line  3 - 3  of  FIGS. 1 and 2 . In addition to the components shown in  FIGS. 1 and 2 ,  FIG. 3  shows how the control/driver electronics  130  may be configured as essentially a bottom layer affixed to substrate  102 . It should be noted that pads  122  and  124  (not shown in  FIG. 3 ) extend from troughs  126  through substrate  102  to provide a direct electrical connection between electronics  130  and nanotubes  120 . Similarly, for an electrostatically coupled embodiment of the present invention, similar electronics could be connected through the substrate to conductive plates or pads present in the walls or floor of the trough. 
       FIG. 3  is useful in illustrating the operation of assembly  100 . During normal operation, assembly  100  is immersed in a working substance, such as a gas or other fluid, or said working substance is introduced into the central chamber via ducts, piping or other means. An external magnetic field is provided by permanent magnet  108 . While a permanent magnet is shown as the source of the magnetic field, persons skilled in the art will appreciate that in this embodiment, as well as other embodiments herein, the external magnetic field may be provided by other sources besides a permanent magnet, such as electromagnetic field coils, or it may be generated locally for each suspended nanotube assembly by means such as other nanotube assemblies of this invention or other nanoscale magnetic field generators such as those in U.S. Pat. No. 6,157,042. 
     Control/driver electronics  130  provide pulsed DC or AC current to nanotubes  120 , which cause the nanotubes  120  to rotate due to interactions between said current and the magnetic field. For example,  FIG. 3  shows that all of the nanotubes are driven to rotate in a clockwise direction, which would thereby force the molecules of the working fluid to travel from left to right across  FIG. 3 , so that they exit the channel at end  128 . For purposes of illustration, molecule  114  and indicator  116  are intended to show the present position of molecule  114  and the path  116  it has taken to reach that location. Similarly, for an electrostatic embodiment of the present invention, voltages applied to plates or pads located in one or more of the sides of the trough may be sequenced using the control/driver electronics to obtain essentially identical rotational motion from each of the nanotube assemblies. 
     When nanotubes  120  are single walled carbon nanotubes, they may be rotated at speeds of up to several gigahertz, because these molecules are so small, light and strong. The velocity of the nanotubes  120  at their maximum radius may be on the order of several thousand meters per second, which may accelerate the molecules of the working substance up to around mach  5 . Such speeds may be particularly useful if assembly  100  is configured as, for example, a vacuum pump, fan, compressor or propulsion system. Other molecular tubes, rods or wires may have similar strength and so would allow high velocities and high energy transfer. 
     Control/driver electronics  130  may also provide sequencing to the current pulses so that different nanotubes  120  are out of phase with each other, but are timed in a manner with respect to other nanotubes that is beneficial to the operation of the system, assembly  100  in this case. For example,  FIG. 3  shows six nanotube assemblies  112 , which have been labeled in even numbers from 132-142. Electronics  130  controls the timing of the current pulses so that none of the six nanotubes  120  is rotating at the same angle (i.e., out of phase with each other).  FIG. 3  shows each of the six nanotubes in a position rotated thirty degrees out of phase from the neighboring nanotubes. 
     When viewed together, the six nanotubes of  FIG. 3  are timed to maximize the force and momentum applied on the molecules of the working fluid. For example, nanotube  132  is rotated parallel to the surface of the channel within assembly  100 . Nanotube  134  is beginning to push the molecules of the working fluid through the channel. Nanotube  136  is rotated an additional thirty degrees so that it does not act to block the incoming molecules and is timed to receive the molecules pushed by nanotube  134 . Nanotubes  138 ,  140  and  142  are each rotated an additional thirty degrees, such that nanotube  142  is rotating back into trough  126  as the molecules of the working fluid exit from the end  128 . 
       FIGS. 5 and 6  provide an illustration of one example of control/driver electronics  130 .  FIG. 5  show how electronics  130  may be essentially affixed to the bottom of substrate  102 . Locating the driving or switching transistors close to their associated nanotube may be preferable for many applications in order to minimize the power required by maintaining low interconnection resistances. The formation of electronics  130  on substrate  102  may be accomplished by any of a variety of conventional manners. As illustrated in this example, each of nanotubes  120  is provided with a driver circuit  150  formed from four transistors  152 - 158 , sensor leads  160 , control lines  153 ,  155 ,  157  and  159 , and transistors  152 ,  154 ,  156  and  158 , respectively. For clarity, only one instance of the individual elements of driver circuit  150  are labeled, but each instance of driver circuit  150  is substantially similar to that shown and described herein. Each instance of driver circuit  150  is associated with one of the nanotube assemblies  112 . The control lines lead to additional electronics, not shown, which are coupled to the transistors for controlling the transistors. 
     Electronics  130  also includes a DC bus formed by lines  162  (hot) and  164  (ground), with each of these DC bus lines attached to half of the transistors. The pads  112 , to which the nanotubes  120  are anchored and connected, extend through the substrate to provide a direct connection to electronics  130 . Each pad is connected to two transistors such that each end can be switched to either of two bus lines in a standard H-bridge driver configuration. Sensor leads  160  measure the voltage across nanotubes  120 , which can provide position and velocity information, and this information may be used to determine which polarity and timing of current pulses should be transferred to the nanotube in order to accelerate it in the proper direction. 
     While driver circuit  150  is shown to include four transistors  152 ,  154 ,  156  and  158 , persons skilled in the art will appreciate that nanotubes  120  may be current pulsed by circuits having only one or two transistors each, if rotation is to be unidirectional. The use of four transistors enables each nanotube  120  to be rotated in either direction. If nanotubes  120  are rotated in a counter clock-wise direction (opposite of that shown), they will push the molecules of the working substance through the channel started from end  128 , rather than exiting there. When used in a power generation embodiment of this invention, the transistors would be timed to transfer the current generated in the nanotubes into an external load. Further, it may be preferable to include other components, either passive or active, to further limit, amplify or otherwise modulate the current flowing through the nanotubes. Persons skilled in the art will also recognize that these electronics may be made as an integrated circuit or integrated transistor array, rather than as discrete components as shown. Electronics  130  may be formed on the substrate  102 , through means such as photolithographic and etching techniques, or the electronics may be attached later through other means. Persons skilled in the art will also recognize that transistors  152 ,  154 ,  156  and  158  may be any of many devices which switch or modulate current, such as, but not limited to bipolar transistors, J-FETS, MOSFETS, switches or transistors made using other nanotubes. As will be shown in a later drawing, an electrostatically coupled embodiment of an assembly similar to assembly  100  with similar function can be made by including pads or plates in the walls or floor of the troughs, with said plates or pads connected to similar control/driver electronics. 
       FIGS. 7-10  show another embodiment of the present invention as nanotube assembly  200 , which is constructed in accordance with the principles of the present invention and is a method of application for this invention. In many aspects, assembly  200  is substantially similar to that described with respect to assembly  100 . Accordingly, the descriptions above apply here equally as well. For convenience, each of the components of assembly  200  that are substantially similar to components of assembly  100  are similarly numbered, except that the first digit is “2” instead of “1”. For example, while each of the individual nanotube assemblies of this invention in  FIGS. 7-10  is labeled  212  versus  112  in  FIGS. 1-6 , they are substantially the same. 
     In fact, it may be noted that, in some aspects, assembly  200  is simply two instances of assembly  100  formed together on either side of a “hot box” chamber  270 , with the chambers of these assemblies containing one or more nanotube assemblies. For example, assembly  100  includes six instances of electromagnetically coupled nanotube assemblies  112  of the present invention, while assembly  200  includes two sets of similar arrays of six electromagnetically coupled nanotube assemblies  212 , with each set of assemblies on ether side of chamber  270  and each nanotube assembly  212  containing a nanotube suspended over a trough between two pads  224 . Thus, assembly  200  may be formed with two assemblies  100  and a central chamber by replacing two upper substrates  110  with a single upper substrate  210 , that includes an additional portion  211  that is configured to be parallel to the surface of permanent magnets  208 , such that the upper interior surface of the channel remains substantially flat. 
     Assembly  200  operates differently than assembly  100  because chamber  270  is heated from an external source, as indicated by arrow  272 . The heat input to chamber  270  may be supplied by various means, including, but not limited to, external combustion of a fuel, a radioisotope thermal source, a waste heat source or solar heating. Accordingly, if assembly  200  is mounted to a microprocessor, the source of heat may simply be the heat generated by the microprocessor, while also providing a heat sink for the microprocessor. Alternatively, those skilled in the art will recognize that the chamber  270  may be any size without departing from this invention, and may contain other features to improve the heat transfer between the heat source  270  and the working fluid which passes through said chamber, where said features may include, but are not limited to, finned protrusions, modified emissivity of surfaces, single-phase heat pipes or two-phase heat pipes. 
     The inclusion of heated chamber  270  between two nanotube assembly channels results in a device that is essentially a nanometer to micrometer scale turbine generator or jet engine. In this instance, the working substance is likely to be a gas, which is compressed by the rotating nanotubes located in subassembly  275 , thereby forcing said gas to enter the heated chamber  270  at an increased pressure. The gas is heated in the chamber and allowed to expand through subassembly  277 , driving the nanotubes as this gas exits. The gas will pass through a Brayton cycle approximately, during its transition through this device. The nanotube assemblies  212  contained in subassembly  275  function as a motorized compressor, being driven by input current from the control/driver electronics  250 . The nanotubes assemblies  212  contained in subassembly  277 , on the other hand, operate as turbine generators, being driven by the hot gas flow exiting chamber  270  and generating electrical currents, with generated power switched into a load by the control/driver electronics or used to drive the compressor. This functionality is essentially the same functionality obtained in macroscale open-cycle Brayton generators and jet engines through the use of turbine wheels. As with those macroscale devices, the system shown in  FIGS. 7-10  can provide a net electrical power or a propulsive thrust based on the heat input. 
       FIGS. 9 and 10  show the control/driver electronics mounted on the opposite side of substrate  202  from the nanotubes and the channel. Each identical nanotube subassembly  212  has an identical associated section of control/driver electronics  250 . Again, the mounting pads  224  extend through the substrate  202  and provide a connection to control driver/electronics. The magnetic fields are provided by permanent magnets  208 , but may be provided by other means as previously described. 
     Alternatively, as with other heat engines, the assembly shown in  FIGS. 7-10  can also be operated as a heat pump or refrigerator to cool an object in contact with chamber  270 , by providing a net positive electrical input to the system. Also, the assembly  200  may be constructed using electrostatically coupled nanotubes in each nanotube assembly  212  instead of the electromagnetically coupled nanotubes shown, as previously described for assembly  100 . 
       FIGS. 11-13  show another alternate embodiment of a nanotube electromechanical assembly  300  constructed in accordance with the principles of the present invention. Assembly  300  is also based on the principles described above with respect to assemblies  200  and  300 , in that it contains one or more of the electromagnetically driven nanotube jump-rope assemblies of the present invention for the purpose of driving a working fluid in a preferred direction. Assembly  300  includes a vacuum pump assembly  360  and a chamber  370 . Vacuum pump  360  includes a lower assembly that is similar to the base of assembly  100 , in that it includes a lower substrate  302 , nanotube assemblies  312 , electronics  330  and side chamber walls  304 . Assembly  300  also includes a channel wall opposite  304 , but it has been removed for illustrative purposes only. 
     Unlike assemblies  100  and  200 , assembly  300  includes an upper assembly which also contains nanotube assemblies  312  and is essentially similar to the lower assembly, differing only to the extent that the location of the nanotube assemblies varies depending on the distance down the channel. Another difference between assembly  300  and those previously discussed is that the driver circuits  350  are located within the pump channel, rather than on the opposite side of the substrate. This location of circuits is arbitrary for proper function of the nanotube assemblies, but when the fluid is compatible with the electronics, such as in a vacuum system, the control/driver electronics  350  may be situated inside the channel so that connection pads  322  and  324  do not need to extend through the substrate. Also, the permanent magnets are not shown in  FIGS. 11-13  and the external magnetic field is simply indicated by arrows  362 , which may again be provided by a permanent magnet or by other means as previously discussed. 
     Operation of assembly  300  is similar to previous assemblies in that a multiplicity of nanotube assemblies  312  function together forcing molecules of a working fluid  314  down the central channel. In this case, a working fluid, which is contained in chamber  370  is pumped through vacuum pump assembly  360  by the upper and lower assemblies of nanotubes. As illustrated in  FIG. 13 , nanotubes  320  in the upper assembly rotate in a clockwise direction, while nanotubes  320  in the lower assembly rotate in a counter-clockwise direction. Thus, the nanotube assemblies in the upper and lower assemblies cooperate, due to the offset location of these nanotubes, to accelerate the molecules of the working fluid  314  out of the exit  328 . The line  316  indicates a potential path of one of these molecules. 
     Accordingly, if the chamber  370  is comprised of a sealed chamber containing gas under ambient conditions, the assembly  300  of  FIGS. 11-13  will perform as a vacuum pump to remove the gas from the chamber and maintain a vacuum condition in the chamber. Alternatively, if the fluid in chamber  370  is comprised of a substantial quantity of liquid or gas, then the assembly  300  of  FIGS. 11-13  will perform as a reaction rocket engine by propelling the fluid at high velocity. Alternatively, multiple assemblies consistent with assembly  300  may be combined to provide an injection system for fuels and oxidants in combustion systems, for fuels and oxidants in chemical rocket engines, or for controlled fluid or gas injection in a variety of chemical and medical applications. Persons skilled in the art will appreciate that if the direction of nanotubes  312  is reversed, assembly  300  will compress gas into chamber  370 . 
       FIGS. 14 and 15  show an additional alternate embodiment of a nanotube electromechanical assembly  400  constructed in accordance with the principles of the present invention. Assembly  400  is also based on the principles described above in that it contains one or more of the electromagnetically driven nanotube jump-rope assemblies of the present invention for the purpose of driving a working fluid in a preferred direction. Accordingly, the same numbering scheme applies, such that nanotubes  420  are substantially similar to nanotubes  120 , and hence the previous discussion also applies to nanotube  420 . 
     The differences between assembly  400  and the previously described assemblies are as follows. Each of assemblies  100 ,  200  and  300  are configured to pump molecules in series, from one nanotube to another. The nanotubes of assembly  400 , however, are configured to pump working substance in parallel, essentially independently of each other. In addition, the upper portion of chamber  470  also serves as the substrate  402  to which control/driver electronics  430  and nanotube assemblies  412  are mounted. Channels  472  are provided through the substrate  402  to allow transfer of the working fluid from the interior of chamber  470 , as indicated by the trajectory  416  of the molecule  414 . In this embodiment, the nanotubes are suspended from posts  422  and  424  to which they are mechanically and electrically connected, with these posts being of sufficient height to prevent the nanotubes from striking the substrate during rotation. These posts may also be flexible to allow increased slack in the nanotube at higher rotational speeds. 
     Similar to assembly  300 , assembly  400  also shows the external magnetic field indicated by arrows  462 , which may still be provided by permanent magnets or other means. Again, the control electronics are shown with four transistors  452 ,  454 ,  456 , and  458  corresponding to each individual nanotube assembly, allowing independent bi-directional control of each nanotube. If the nanotubes are desired to be synchronized, however, a parallel array of such assemblies could be driven by a single instance of the control/driver electronics by electrically connecting all posts  422  to one side of the driver circuit and connecting all posts  424  to the other side of the driver circuit. Alternatively, if a unidirectional rotation of the nanotubes is desired then the driver circuit may contain only one or two transistors instead of the four shown. Persons skilled in the art will appreciate that the lower chamber of assembly  400  may be removed such that assembly  400  may be utilized as a propulsion system. 
     Pumping the fluid simultaneously through parallel channels with multiple nanotubes, as in assembly  400 , can increase the flow rate obtained by the assembly, whereas pumping the fluid sequentially through a singles channel, as in assemblies  100 ,  200  and  300 , can increase the pressure difference obtained by the assembly. Accordingly, it is apparent that combinations of parallel pumping and sequential pumping arrays of nanotubes can be used to obtain a variety of flow rates and pressure differences. Similarly, the variety of flow rates and pressure differentials seen in generation applications, such as wind power generation or heat engines, can be utilized by combinations of parallel nanotube and series nanotube arrays. 
       FIGS. 16 ,  17  and  18  show an additional alternate embodiment of a nanotube electromechanical assembly, assembly  500 , in which the individual electromagnetically coupled nanotubes  520  are used to transmit and receive electromagnetic signals, in accordance with the principles of the present invention. Nanotube assemblies such as assembly  500  could also be applied as magnetic field sensors or magnetic field generators. Furthermore, assemblies such as assembly  500  could be applied as a READ/WRITE head for a magnetic storage medium. Assembly  500  includes a lower substrate  502 , to which three suspended nanotube assemblies are fabricated. Each nanotube assembly  512  includes a nanotube  520  mounted between posts  522  and  524  and driver electronics circuit  550 , which includes four transistors  552 ,  554 ,  556  and  558  and interconnection circuitry. An external magnetic field is applied to assembly  500  as indicated by arrow  562 . 
     As shown in  FIGS. 16-18 , an electric charge can be applied to nanotubes, as indicated by the “+” signs on each of nanotubes  520 , by the application of a bias voltage to either of pads  522  or  524  or to assembly  500  itself. Assembly  500  may be operated as an electromagnetic transmitter by rapidly rotating nanotubes  520 , which thereby accelerates the charge stored therein. The accelerated charge creates electromagnetic radiation at a frequency that is substantially equal to the rotational frequency of the nanotubes. The accelerated charge creates electromagnetic radiation at a frequency that is substantially equal to the rotational frequency of the nanotubes. Unlike a conventional antenna in which charge must be moved through one or more resistive elements, the accelerated charge in the nanotubes suffers significantly less resistive losses and operation is significantly more efficient than conventional devices. 
     Nanotube assembly  500  may be operated as an electromagnetic receiver by similarly storing charge on nanotubes  520 . The charged nanotubes would then vibrate in response to external electromagnetic signals, and the vibrational motion could then be converted into an AC voltage as the rotating tube moves through the assembly&#39;s external DC magnetic field  562 . While control/driver electronics  550  is shown as including the four transistor circuits previously described, there is less likelihood of a need for bi-directional rotation in assembly  500  than in the previously described assemblies. Accordingly, it may be more efficient and cost effective for driver circuits  550  to be formed from one or two transistors. It may be preferable to suspend the nanotubes  520  across a trench, as in assemblies  100 ,  200  or  300 , rather than on posts as shown in  FIG. 500  without loss of functionality in this application. Also, as with other assemblies shown, it may be preferable to have one or more conductive plates or pads embedded in the surface of substrate  502  and connected to control/driver electronics  550  such that nanotube  520  may be driven via electrostatic forces, in which case, the applied magnetic field  562  is not necessary. Furthermore, nanotube assembly  500  may be constructed with uncharged nanotubes such that nanotube assembly  500  does not create unwanted electromagnetic waves which otherwise may be provide by fast-spinning charged nanotubes. 
       FIGS. 19 and 20  show an additional alternate embodiment of a nanotube electromechanical assembly  600  constructed in accordance with the principles of the present invention. Assembly  600  is also based on multiple instances of an electromagnetically coupled suspended nanotube with the principles discussed above and accordingly, the same numbering scheme applies here as well; e.g., nanotubes  620  are substantially similar to nanotubes  120 , and therefore, the earlier discussion above also applies to nanotubes  620 . 
     In particular, assembly  600  is substantially similar in configuration to nanotube assembly  500  described above in that it is based on a single substrate  602 , and includes nanotubes  620  suspended between posts which are electrically connected to control driver electronics fabricated on the surface of substrate  602 . A magnetic field indicated by arrows  662  is applied by means external to the drawing. Although very similar to assembly  500  without the applied bias charge, assembly  600  illustrates that the same assembly can be applied to operate as a propulsion system. To indicate the use as a propulsion system, the illustrations of  FIGS. 19 and 20  include the working system molecules  614  and path indicator  616  for these molecules. 
     In nanotube assembly  600 , nanotubes  620  are rotated at high speed by application of pulsing currents provided that an external magnetic field is applied to assembly  600 .  FIGS. 19 and 20  illustrate the impact of rotating nanotubes  620  with molecules  614 , and the resultant drastic change of path of molecules  614 . The molecules of the working substance, preferably air in this instance, bounce off of the nanotubes at high speeds. The molecules that are driven into substrate  602  by interaction with the nanotubes will bounce off of the substrate at higher speeds than those that are struck away from the substrate; i.e., those molecules which are struck by the nanotubes will have a higher impact velocity with the substrate. This action results in a net positive force on substrate  602  opposite the direction of the departing molecules, so that it is effectively propelled by the impacts of the air molecules. 
       FIGS. 21 through 23  show an additional alternate embodiment of a nanotube electromechanical assembly  700  constructed in accordance with the principles of the present invention. Assembly  700  is also based on multiple instances of an electromagnetically coupled suspended nanotube with the principles discussed above and accordingly, the same numbering scheme applies here as well; e.g., nanotubes  720  are substantially similar to nanotubes  120 , and therefore, the earlier discussion above also applies to nanotubes  720 . 
     In particular, assembly  700  is substantially similar in configuration to nanotube assembly  600  described above, in that it is based on a single substrate  702  and includes nanotubes  720  suspended between posts  722  and  724 . Also, assembly  700  is substantially similar in configuration to nanotube assembly  100  described above, the electrically conductive posts extend through the substrate  702  and are electrically connected to control driver electronics fabricated on the opposite surface of the substrate  702 . In this assembly, the side of substrate  702  is configured such that each of the electromagnetically coupled nanotube assemblies is located entirely in a trough  726 . This configuration of the sides of substrate may be a preferred configuration when assembly  700  is applied as a propulsion system, in which those molecules that are accelerated horizontally are able to contribute to the vertical thrust on the substrate. 
     As molecules  714  travel toward substrate  702 , some of them are struck by nanotubes  720  while these suspended nanotubes are being driven at high rotational speed. Although some of the molecules will travel in paths similar to assembly  600 , other molecules will have multiple impacts with the various side walls of substrate  702 , such as the path  776 . The configuration of troughs  726  and the resultant impact path  776  is that the energy from the horizontally accelerated substrate  702  to be propelled generally upward. Molecules that have single collisions with these side walls will impart both vertical and horizontal forces to the substrate, so, when the walls are symmetrically configured as in assembly  700 , the horizontal components of force will average to near zero over a large number of collisions such that a net remaining force in a direction parallel to that of external magnetic field  762 . Accordingly, side walls could be sloped in many configurations depending on the mean propulsive force desired. Furthermore, instead of the flat sides shown in  FIGS. 21-23 , the walls of the trench could be shaped in many ways to otherwise direct or amplify the mean resultant force, such as making a trench with a parabolic cross-section containing the nanotube in the focus. 
       FIGS. 24 through 26  show an additional alternate embodiment of a nanotube electromechanical assembly  800  constructed in accordance with the principles of the present invention. Assembly  800  is also based on multiple instances of an electromagnetically coupled suspended nanotube with the principles discussed above and accordingly, the same numbering scheme applies here as well; e.g., nanotubes  820  are substantially similar to nanotubes  120 , and therefore, the earlier discussion above also applies to nanotubes  820 . 
     Nanotube assembly  800  includes a base circuit board  880 , to which two substrate-based assemblies  802  are mounted. Each of assemblies  802  includes thirty-five electromagnetically coupled nanotube assemblies, each of which includes a suspended nanotube  820  mounted between posts  822  and  824 . Assemblies  802  also include control/driver electronics  830 , which includes four transistors configured as previously shown and described with respect to assemblies  100 - 700 . Also as previously described, if unidirectional rotation is sufficient for the application, the control/driver electronics may be reduced to two or one transistor for each nanotube in the assembly. Similarly, if synchronous action is desired from one or more nanotubes, a single instance of control/driver electronics can connect to the array of nanotube assemblies. 
     Each of the two instances of assembly  802  also includes four wire traces  882  that provide an interface between assembly  802  and other external circuitry, such as control logic circuitry or monitoring circuitry. Wire traces  882  are routed along circuit board  880  and connected to output pins  884 . Nanotube assembly  800  also includes a housing  890  that, in conjunction with base  892 , permits circuit board  880  to be placed in a vacuum environment. This vacuum environment is advantageous because it reduces aerodynamic drag on the rapidly spinning or vibrating nanotubes, thereby increasing efficiency for many applications 
     Nanotube assembly  800  may be used in a wide variety of applications and simply illustrates one embodiment for constructing a large array of electromagnetically coupled nanotube devices. For example, as previously described, assembly  800  may be used as an electromagnetic transmitter and/receiver, or it may be used to measure or generate magnetic fields. Alternatively, this assembly may be used to store energy as kinetic energy of the spinning nanotubes, which may then be discharge as electrical energy as desired. Assembly  800  may be used as a gyroscope or accelerometer because if external acceleration is present, spinning nanotubes  820  will flex and provide a voltage distinguishable from those instances in which no acceleration is present. Nanotube assembly  800  may also be utilized to sense magnetic fields. 
       FIG. 27  shows an additional alternate embodiment of a nanotube electromechanical assembly  900  constructed in accordance with the principles of the present invention. Assembly  900  is based on multiple instances of an electrostatically coupled suspended nanotube of this invention. An electrostatically coupled nanotube assembly, such as those shown in  FIG. 27 , may be substituted in place of the electromagnetically coupled nanotube assemblies, by removing the magnetic field and adding structures for applying the electrostatic potential. The portion shown in  FIG. 27  includes a lower substrate base  902 , channel side walls  904  and  906 , three nanotube assemblies  912 , and two conductive surfaces  938  and  939  attached to base  902 . For clarity, only one of the three nanotube assemblies of  FIG. 27  is labeled, however the description applies to each of them equally. In this assembly, the conductive surfaces  938  and  939  are electrically connected to the corresponding pad of the neighboring assembly. Pads  922  and  924  are mounted to channel side walls  904  and  906 , which may contain a conductive element to electrically interconnect nanotubes  920  or may be conductive itself. 
     The ends of each nanotube  920  are mounted, respectively, to one of the pads  922  and  924 . It may be preferable to include some slack in nanotube  920  so that it hangs like a jump rope as shown. Alternatively, it may be preferable to mount nanotube  920  across pads  922  and  924  such that there is some tension between pads  922  and  924 , in which case, the device would take advantage of the vibration of the nanotube rather than the rotation, or would take advantage of a smaller rotational amplitude at a higher frequency than a nanotube with lower tension. Alternatively, it may be preferable to mount nanotube  920  across pads  922  and  924  such that one or more of said pads is on a flexible member, in which case, the ends of the nanotube would become drawn closer together as the tension in the nanotube is increased at high rotational speeds; thereby allowing higher amplitudes and higher energies that one could obtain using a nanotube which was mounted with no slack to rigidly positioned pads. 
     Each of nanotubes  920  may, for example, be constructed of a material such as carbon; an example being a single walled carbon nanotube (a tubular fullerene) having a diameter of approximately 1 to 20 nanometers and a length from 20 to hundreds of nanometers (persons skilled in the art will appreciate that the dimensions of nanotubes  120  may be varied without departing from the spirit of the present invention). One advantage in using single walled carbon nanotubes for nanotubes  920  is that they are formed of a single molecule. Therefore, they may be bent endlessly at will within dimensional limits without damaging them, and without losing a lot of energy to friction. A further advantage of using single walled carbon nanotubes for nanotubes  920  is that the tensile strength is very high, allowing high vibrational and rotational energies. Another further advantage of using single walled carbon nanotubes for nanotubes  920  is the high electrical conductivity of these nanotubes. Alternatively, each of members  920  may be another suitable structure which is not a single molecule, such as, but not limited to, a carbon filament, a multiwalled carbon nanotube, or simply an electrically conductive, flexible piece of wire. Alternatively, the nanotube may be any of many other suitable molecular structures, including, but not limited to, tubular boron carbide molecules, tubular carbon nitride molecules or a single crystal filament such as quartz. In addition, it may be preferable to bond other molecular structures at one or more points along the primary nanotube or molecular wire to increase the mass or the cross-sectional size of the rotating element. 
     Control/driver electronics are not shown, but may be affixed to the opposite side of substrate base  902  or may be external to the assembly. These control/driver electronics are substantially similar to those shown previously, except that these control/driver electronics are connected to fixed conductive surfaces  938  and  939 . All suspended nanotubes are connected to a DC voltage. The control/driver electronics provide pulsed DC or AC voltage to the fixed conductive surfaces  938  and  939 , which causes the nanotubes  920  to rotate due to electrostatic forces between said surfaces and the nanotube. Similarly, the fixed conductive surfaces may be attached to different static voltages while the control/driver electronics applies a pulsed DC or AC voltage to the suspended nanotubes, thereby obtaining similar electrostatic forces and similar motion from the nanotube. The electrostatic forces and resulting motion are illustrated in the following figures. 
     For example of these electrostatic forces,  FIG. 28  shows a view of one of the nanotube assemblies  912  from  FIG. 27 , as viewed along the axis of the nanotube  920 .  FIG. 28  indicates a fixed conductive surface  938  that has a voltage, or charge, which is negative with respect to the voltage, or charge, on suspended nanotube  920 . The minus and plus signs on these elements indicate the difference in electrical potential. The resulting electrostatic attractive force between these elements is indicated with the force vector, F. This resulting force causes the nanotube to move toward the fixed conductive surface  938 . 
       FIG. 29  again shows a view of one of the nanotube assemblies  912  from  FIG. 27 , as viewed along the axis of the nanotube  920 .  FIG. 29  indicates a fixed conductive surface  939  that has a voltage, or charge, which is the same as the voltage, or charge, on suspended nanotube  920 . The plus signs on these elements indicate that the electrical potential is the same. The resulting electrostatic repulsive force between these elements is indicated with the force vector, F. This resulting force causes nanotube  920  to move away from the fixed conductive surface  939 . 
       FIG. 30  again shows a view of one of the nanotube assemblies  912  from  FIG. 27 , as viewed along the axis of the nanotube  920 , showing how the effects of both fixed conductive surfaces  938  and  939  can be used to move the nanotube.  FIG. 30  indicates a fixed conductive surface  938  that has a voltage, or charge, which is the same as the voltage, or charge, on suspended nanotube  920 , and a fixed conductive surface  939  that has a voltage, or charge, which is negative with respect to the voltage, or charge, on suspended nanotube  920 . The resulting electrostatic forces applied on the nanotube by these charged plates are indicated with the force vectors, F(+) and F(−). The resulting combined force causes nanotube  920  to move away from the fixed conductive surface  938  and toward fixed conductive surface  939 . 
       FIG. 31  shows an additional alternate embodiment of a nanotube electromechanical assembly  1000  constructed in accordance with the principles of the present invention. Assembly  1000  is based on multiple instances of an electrostatically coupled suspended nanotube. The portion shown in  FIG. 31  includes a lower substrate base  1002 , channel side wall  1004 , three nanotube assemblies  1020 , and two conductive surfaces  1038  and  1039  attached to base  1002 . Pad  1022  is mounted to channel side wall  1004 , which may contain a conductive element to electrically interconnect nanotubes  1020  to external circuitry or may be conductive itself. 
     The assembly  1000  in  FIG. 31  differs from the assembly in  FIG. 27  in that only one end of the nanotube is fixed.  FIG. 31  shows one end of each nanotube  1020  mounted to pads  1022 , such that the nanotube is suspended parallel to substrate base. All other components of  FIG. 31  are the same as in  FIG. 27 , such that similar electrostatic forces can be applied to the nanotubes  1020  by controlling voltage pulses as described above. Accordingly,  FIGS. 28-30  and the descriptions of  FIGS. 28-30  apply equally well to the behavior of assembly  1000  of  FIG. 31 . 
       FIG. 32  shows an additional alternate embodiment of a nanotube electromechanical assembly  1100  constructed in accordance with the principles of the present invention. Assembly  1100  is based on multiple instances of an electrostatically coupled suspended nanotube, but shows these electrostatically coupled nanotube assemblies substituted in place of the electromagnetically coupled nanotube assemblies in assembly  100 , by removing the magnetic field and adding structures for applying the electrostatic potential. 
       FIG. 32  shows six individual electrostatically coupled nanotube assemblies  1112  on a single substrate base  1102 . Each nanotube assembly is again comprised of suspended nanotubes  1120  mounted between two end connections  1122  and  1124 . As in assembly  100 , the nanotubes are again suspended across troughs, such that the lower half of the nanotubes rotational travel is inside the trough. Fixed conductive surfaces  1138  and  1139  are attached to the side walls of each trough, with these conductive surfaces having electrical connections through the substrate  1102  to control/driver electronics on the other side. Side walls  1104  and  1106  are attached to the substrate base  1102 , and a top substrate (not shown) would be attached to the top of these walls, such that the working substance is constrained to a central channel. 
     The fixed conductive surfaces are placed such that electrostatic forces can be applied to the nanotube from either side. In this configuration, the control/driver electronics would alternately apply voltage pulses to the two conductive surfaces, resulting in alternating forces which would drive the nanotubes to rotate in a clockwise direction (similar to the operation of  FIGS. 28-30 ). Impacts from these rotating elements would thereby force the molecules of the working fluid to travel from left to right across  FIG. 32 , so that they are pumped through the channel at end  1128 . For purposes of illustration, molecule  1114  and indicator  1116  are intended to show the present position of molecule  1114  and the path  1116  it has taken to reach that location. These six nanotube assemblies  1112  may be driven independently by providing a set of transistor control elements for each fixed conductive surface, or these six assemblies may be controlled together in a synchronized manner by interconnecting pads  1138  of each assembly and pads  1139  of each assembly while providing only one set of transistor control elements for all six nanotube assemblies  1112 . 
     Assembly  1100  could be used for any of the assemblies shown previously which contain assemblies similar to assembly  100 . Applications for these assemblies may include, for example, compressors, fans, turbine-like generators, heat engines, vacuum pumps, propulsion systems, magnetic field sensors, magnetic field generators, gyroscopes and kinetic energy storage devices, as previously described. Furthermore, additional molecules could be bonded to a nanotube of the present invention. Doing so may, for example, increase the cross section or inertia of the nanotube. Depending on the application, such characteristics could be advantageously utilized. For example, a large cross section may be desirable for pump applications while a large inertia may be desired in energy storage applications. 
     Persons skilled in the art will appreciate that two components do not have to be connected or coupled together in order for these two components to electrically interact with each other. Thus, persons skilled in the art will appreciate that two components are electrically coupled together, at least for the sake of the present application, when one component electrically affects the other component. Electrical coupling may include, for example, physical connection or coupling between two components such that one component electrically affects the other, capacitive coupling, electromagnetic coupling, free charge flow between two conductors separated by a gap (e.g., vacuum tubes), and inductive coupling. 
     Additional advantageous nanometer-scale electromechanical assemblies are described in commonly assigned copending U.S. patent application Ser. No. 10/453,783 to Pinkerton et. al, entitled “Nanoelectromechanical Transistors and Switch Systems,” commonly assigned copending U.S. patent application Ser. No. 10/453,199 to Pinkerton et. al, entitled “Nanoelectromechanical Memory Cells and Data Storage Devices,” and commonly assigned copending U.S. patent application Ser. No. 10/453,373 to Pinkerton et. al, entitled “Energy Conversion Systems Utilizing Parallel Array of Automatic Switches and Generators,” which are all hereby incorporated by reference in their entirely and filed on the same day herewith. 
     From the foregoing description, persons skilled in the art will recognize that this invention provides nanometer-scale and micrometer scale electromechanical assemblies that may be utilized as, for example, motors, generators, pumps, fans, compressors, propulsion systems, transmitters, receivers, heat engines, heat pumps, magnetic field sensors, magnetic field generators, inertial energy storage and acoustic energy conversion. In addition, persons skilled in the art will appreciate that the various configurations described herein may be combined without departing from the present invention. It will also be recognized that the invention may take many forms other than those disclosed in this specification. Accordingly, it is emphasized that the invention is not limited to the disclosed assemblies and methods, but is intended to include variations to and modifications therefrom which are within the spirit of the following claims.