Nanoelectromechanical transistors and switch systems

Abstract

Nanoelectromechanical switch systems (NEMSS) are provided that utilize the mechanical manipulation of nanotubes. Such NEMSS may realize the functionality of, for example, automatic switches, adjustable diodes, amplifiers, inverters, variable resistors, pulse position modulators (PPMs), and transistors. In one embodiment, a nanotube is anchored at one end to a base member and coupled to a voltage source that creates an electric charge at the tip of the nanotube's free-moving-end This free-moving end may be electrically controlled by applying an additional electric charge, having the same (repelling) or opposite (attracting) polarity as the nanotube, to a nearby charge member layer. A contact layer is located in the proximity of the free-moving end such that when a particular electric charge is provided to the nanotube (or charge member layer), the nanotube electrically couples with the contact layer.

What is claimed is:  
     
         1 . A nanoelectromechanical system comprising: 
 a base member;    a mounting assembly attached to said base member;    a first electrical contact;    a nanometer-scale beam fixed to said mounting assembly, wherein a first portion of said beam is free-to-move, said beam has a first charge, and said first free-moving portion being able to electrically couple with said first electrical contact at a contact rate; and    a charge member, having a second charge, located in the proximity of said first free-moving portion such that said second charge interacts with said first charge to affect said contact rate.    
     
     
         2 . The nanoelectromechanical system of  claim 1 , wherein said nanometer-scale beam is a nanotube.  
     
     
         3 . The nanoelectromechanical system of  claim 1 , wherein said first free-moving portion and said fixed portion are located at opposite ends of said nanometer-scale beam.  
     
     
         4 . The nanoelectromechanical system of  claim 1 , wherein said first charge is provided by a first voltage source.  
     
     
         5 . The nanoelectromechanical system of  claim 1 , wherein said second charge is provided by a second voltage source.  
     
     
         6 . The nanoelectromechanical system of  claim 1  further comprising: 
 a source of thermal energy, wherein said thermal energy affects said contact rate.  
 
     
     
         7 . The nanoelectromechanical system of  claim 1  further comprising: 
 sense circuitry for determining said contact rate.  
 
     
     
         8 . The nanoelectromechanical system of  claim 1  further comprising: 
 control circuitry coupled to said charge member for providing voltage signals to said charge member.  
 
     
     
         9 . The nanoelectromechanical system of  claim 1  further comprising: 
 control circuitry coupled to said nanometer-scale beam for providing voltage signals to said nanometer-scale beam.  
 
     
     
         10 . The nanoelectromechanical system of  claim 1  further comprising: 
 a second electrical contact coupled to said beam, wherein current flows between said first and second electrical contacts when said nanometer-scale beam electrically couples said first electrical contact.  
 
     
     
         11 . The nanoelectromechanical system of  claim 1  wherein said first electrical contact is located between said charge member and said nanometer-scale beam.  
     
     
         12 . The nanoelectromechanical system of  claim 11  wherein said contact rate is greater when said first and second charges have opposite polarities then when said first and second contacts have the same polarity.  
     
     
         13 . The nanoelectromechanical system of  claim 11  wherein said first and second charges are of opposite polarities and increasing the intensity of said first charge increases said contact rate.  
     
     
         14 . The nanoelectromechanical system of  claim 11  wherein said first and second charges have the same polarity and increasing the intensity of said first charge decreases said contact rate.  
     
     
         15 . The nanoelectromechanical system of  claim 1  wherein said nanometer-scale beam is located between said first electrical contact and said charge member.  
     
     
         16 . The nanoelectromechanical system of  claim 15  wherein said contact rate is greater when said first and second charges are of the same polarity then when said first and second charges have opposite polarities.  
     
     
         17 . The nanoelectromechanical system of  claim 1  further comprising: 
 an isolation layer located between said charge member and said first electrical contact.  
 
     
     
         18 . The nanoelectromechanical system of  claim 1  further comprising: 
 a second charge member located on substantially the opposite side of said nanometer-scale beam as said charge member, wherein said second charge member has a third charge that affects said contact rate.  
 
     
     
         19 . The nanoelectromechanical system of  claim 18  further comprising: 
 a third electrical contact, wherein said third electrical contact is located between said second charge member and said nanometer-scale beam and said first electrical contact is located between said charge member and said nanometer-scale beam.  
 
     
     
         20 . The nanoelectromechanical system of  claim 19 , wherein said first and third electrical contacts are electrically coupled together.  
     
     
         21 . The nanoelectromechanical system of  claim 1 , wherein said nanometer-scale beam is fixed to said mounting assembly at both ends and said first free-moving portion is located between said both ends.  
     
     
         22 . The nanoelectromechanical system of  claim 1 , further comprising: 
 a second electrical contact coupled to said beam; and    a resistor coupled to said second electrical contact.    
     
     
         23 . The nanoelectromechanical system of  claim 1 , wherein said second charge is provided by an AC voltage source.  
     
     
         24 . The nanoelectromechanical system of  claim 1 , wherein said second charge is provided by a DC voltage source.  
     
     
         25 . A nanoelectromechanical system comprising: 
 a base member;    a nanometer-scale beam fixed at one end to said base member, said beam having a first charge and having a portion that is free-to-move;    a charge member layer having a second charge;    a first electrical contact located within the proximity of said beam such that interactions between said first and second charges determines if said free-moving portion electrically couples to said first electrical contact; and    sense circuitry for sensing said electrical coupling.    
     
     
         26 . The nanoelectromechanical system of  claim 25 , wherein said sense circuitry is coupled to said first electrical contact.  
     
     
         27 . The nanoelectromechanical system of  claim 26 , wherein said electrical coupling is a galvanic coupling.  
     
     
         28 . The nanoelectromechanical system of  claim 25  further comprising: 
 control circuitry coupled to said beam for providing electrical signals to said beam.  
 
     
     
         29 . The nanoelectromechanical system of  claim 28 , wherein said control circuitry is operable to adjust the polarity and magnitude of said electrical signals.  
     
     
         30 . The nanoelectromechanical system of  claim 25  further comprising: 
 control circuitry coupled to said charge member layer for providing electrical signals to said charge member layer.  
 
     
     
         31 . The nanoelectromechanical system of  claim 30  wherein said control circuitry is operable to adjust the polarity and magnitude of said electrical signals.  
     
     
         32 . The nanoelectromechanical system of  claim 25  wherein said beam is a nanotube.  
     
     
         33 . The nanoelectromechanical system of  claim 25  further comprising: 
 a magnetic field, wherein said magnetic field creates a temporary bond between said first electrical contact and said free-moving portion when current is flowing through said beam.  
 
     
     
         34 . The nanoelectromechanical system of  claim 33 , wherein said temporary bond is broken by decreasing the intensity of said second charge.  
     
     
         35 . The nanoelectromechanical system of  claim 33 , wherein said temporary bond is broken by changing the polarity of said second charge.  
     
     
         36 . The nanoelectromechanical system of  claim 33 , wherein said temporary bond is broken by changing the temperature around said beam.  
     
     
         37 . The nanoelectromechanical system of  claim 33  further comprising: 
 a light source, wherein said temporary bond is broken by changing the intensity of light impinging said beam.  
 
     
     
         38 . The nanoelectromechanical system of  claim 33 , wherein said temporary bond is broken by changing the intensity of said first charge.  
     
     
         39 . The nanoelectromechanical system of  claim 33 , wherein said temporary bond is broken by changing the polarity of said first charge.  
     
     
         40 . The nanoelectromechanical system of  claim 33 , wherein said temporary bond is broken by changing the intensity of said magnetic field.  
     
     
         41 . The nanoelectromechanical system of  claim 25 , wherein said first electrical contact is located, at least in part, between said free-moving portion and said charge member.  
     
     
         42 . The nanoelectromechanical system of  claim 41 , wherein said electrical coupling occurs when said first and second charges have opposite polarities.  
     
     
         43 . The nanoelectromechanical system of  claim 25 , wherein said free-moving portion is located, at least in part, between said first electrical contact and said charge member.  
     
     
         44 . The nanoelectromechanical system of  claim 43 , wherein said electrical coupling occurs when said first and second charges have the same type of polarity.  
     
     
         45 . A nanoelectromechanical transistor comprising: 
 a first electrically conductive contact layer;    a second electrically conductive contact layer;    a nanotube having a first and a second end, wherein said first end is fixed to said first contact layer and said second end is free-to-move with respect to said first contact; and    a charge member layer, wherein said second end of said nanotube electrically couples to said second contact layer when an appropriate charge is applied to said charge member layer to physically move said second end.    
     
     
         46 . The nanoelectromechanical transistor of  claim 45 , wherein said charge attracts said second end to said charge member layer.  
     
     
         47 . The nanoelectromechanical transistor of  claim 45 , wherein said charge repels said second end away from said charge member layer.  
     
     
         48 . The nanoelectromechanical transistor of  claim 45 , wherein a portion of said first end of said nanotube is fixed to said first contact layer by a retaining layer.  
     
     
         49 . The nanoelectromechanical transistor of  claim 45 , wherein an non-conducting isolation layer separates said charge member layer, at least in part, from said second contact layer.  
     
     
         50 . The nanoelectromechanical transistor of  claim 45  further comprising: 
 a magnetic field, wherein said magnetic field creates a Lorentz force on said nanotube when said second end is electrically coupled to said second contact layer and is conducting a current that bonds said second contact layer and said second end together.  
 
     
     
         51 . The nanoelectromechanical transistor of  claim 45 , wherein said nanotube has a first charge.  
     
     
         52 . The nanoelectromechanical transistor of  claim 45  further comprising: 
 a resistive layer; and  
 a third contact layer separated from said first contact layer by said resistive layer.  
 
     
     
         53 . A nanoelectromechanical transistor comprising: 
 a first electrically conductive contact layer;    a second electrically conductive contact layer;    a nanotube having a first end and a second end, wherein said first end is fixed to said first contact layer and said second end is free-to-move; and    a charge member layer, wherein said second end electrically couples with said second contact layer at a contact rate.    
     
     
         54 . The nanoelectromechanical transistor of  claim 53 , wherein said contact rate increases as the voltage applied to said charge member layer increases.  
     
     
         55 . The nanoelectromechanical transistor of  claim 53 , wherein thermal vibrations affect said contact rate such that said contact rate increases as temperature increases.  
     
     
         56 . The nanoelectromechanical transistor of  claim 53 , wherein said contact rate is non-zero when a zero-voltage is applied to said second contact member.  
     
     
         57 . The nanoelectromechanical transistor of  claim 53 , wherein said contact rate is representative of an analog signal applied to said charge member layer and said contact rate is utilized as a digital signal at said first contact layer that is representative of said analog signal.  
     
     
         58 . The nanoelectromechanical transistor of  claim 53 , wherein said contact rate is representative of an analog signal applied to said charge member layer and said contact rate is utilized as a digital signal at said second contact layer that is representative of said analog signal.  
     
     
         59 . The nanoelectromechanical transistor of  claim 53  further comprising: 
 a light source that is focused on said nanotube, wherein the intensity of said light affects said contact rate.  
 
     
     
         60 . A nanoelectromechanical transistor comprising: 
 a first contact layer;    a nanotube having a first portion that is fixed to said first contact layer and a second portion that is free-to-move;    a second contact layer placed in the proximity of said second end of said nanotube such that said second portion is operable to bend and physically contact said second contact layer; and    a light source focused, at least in part, on said nanotube.    
     
     
         61 . The nanoelectromechanical transistor of  claim 60 , wherein said second portion of said nanotube electrically couples with said second contact layer when the intensity of said light source surpasses a threshold intensity.  
     
     
         62 . The nanoelectromechanical transistor of  claim 60 , wherein said light source is a laser.  
     
     
         63 . The nanoelectromechanical transistor of  claim 60 , wherein said light source is a light emitting diode.  
     
     
         64 . The nanoelectromechanical transistor of  claim 60 , wherein said light source is sunlight.  
     
     
         65 . A method for making a nanoelectromechanical assembly comprising: 
 laying a first conductive layer on a substrate;    forming an isolation layer above said conductive layer;    laying a second conductive layer above a first portion of said isolation layer;    placing a first end of a nanotube on said second conductive layer, wherein the opposite end of said nanotube is free-to-move; and    laying a third conductive layer in the proximity of said free-to-move end of said nanotube such that if said free-to-move end was bent a certain amount said free-to-move end would contact said third conductive layer.    
     
     
         66 . The method of  claim 65  wherein said third conductive layer is placed above a second portion of said isolation layer and beneath said opposite end of said nanotube.  
     
     
         67 . The method of  claim 65  wherein said certain amount is the height difference between said second conductive layer and said third conductive layer.  
     
     
         68 . The method of  claim 65  wherein said forming of said second and third conductive layers further comprises: 
 forming a general conductive layer on said isolation layer; and  
 etching away a portion of said general conductive layer to create said forming of said second and third conductive layers.  
 
     
     
         69 . The method of  claim 65  further comprising forming a non-conductive layer above said first end of said nanotube and at least a portion of said second conductive layer.  
     
     
         70 . The method of  claim 65  wherein said placing said first end of said nanotube on said second conductive layer further comprises: 
 forming a support layer adjacent to said second conductive layer and placing said free-to-move portion on said support layer; and  
 removing said support layer after said first end of said nanotube has been anchored to said second conductive layer.  
 
     
     
         71 . A method for making a nanoelectromechanical assembly, said method comprising: 
 laying a first conductive layer on a substrate;    forming an isolation layer above said conductive layer;    laying a second conductive layer above a first portion of said isolation layer;    growing a nanotube on said second conductive layer, wherein a first end of said nanotube is self-attached to said second conductive layer and the opposite end of said nanotube is free-to-move when said growing is complete; and    laying a third conductive layer in the proximity of said free-to-move end of said nanotube such that if said free-to-move end was bent a certain amount said free-to-move end would contact said third conductive layer.    
     
     
         72 . The method of  claim 71  wherein said third conductive layer is placed above a second portion of said isolation layer and beneath said opposite end of said nanotube.  
     
     
         73 . The method of  claim 71  wherein said certain amount is the height difference between said second conductive layer and said third conductive layer.  
     
     
         74 . The method of  claim 71  further comprising forming a non-conductive layer above said first end of said nanotube and at least a portion of said second conductive layer.  
     
     
         75 . The method of  claim 71  wherein said forming of said second and third conductive layers further comprises: 
 forming a general conductive layer on said isolation layer; and  
 etching away a portion of said general conductive layer to create said forming of said second and third conductive layers.  
 
     
     
         76 . A method for making a nanoelectromechanical assembly comprising: 
 laying a first conductive layer on a substrate;    forming an isolation layer above said conductive layer;    laying a second conductive layer above a first portion of said isolation layer;    growing a nanotube on the side of said second conductive layer, wherein a first end of said nanotube is self-attached to the side of said second conductive layer, and a second end of said nanotube is free-to-move; and    laying a third conductive layer in the proximity of said free-to-move end of said nanotube such that if said free-to-move end was bent a certain amount said free-to-move end would contact said third conductive layer, wherein the longitudinal axis of said nanotube is parallel with said third conductive layer.    
     
     
         77 . A nanoelectromechanical system comprising: 
 a base member; and    a plurality of nanoelectromechanical transistors, each of said nanoelectromechanical transistors comprising:    a first electrically conductive layer;    a nanometer-scale mechanically flexible and electrically conductive beam able to electrically couples to said first conductive layer as a result of a displacement of said beam by an electric field; and    a second electrically conductive layer that is coupled to said beam.    
     
     
         78 . The nanoelectromechanical system of  claim 77  wherein said nanometer-scale beam is a carbon nanotube.  
     
     
         79 . The nanoelectromechanical system of  claim 77  wherein said nanometer-scale beam is a nano-wire.  
     
     
         80 . The nanoelectromechanical system of  claim 77  further comprising sense circuitry coupled to said first conductive layer for determining the rate that said beam electrically contacts said first conductive layer for a period of time.  
     
     
         81 . The nanoelectromechanical system of  claim 77  further comprising control circuitry coupled to said second conductive layer for providing electrical signals to said second conductive layer.  
     
     
         82 . A method for operating a nanoelectromechanical transistor comprising: 
 applying a first charge on a nanometer-scale beam that is fixed to a mounting assembly, said nanometer-scale beam having a first portion that is free to move;    applying a second charge to a conductive charge member layer, that is placed in the proximity of said first free-moving portion such said first and second charges interact with each other; and    sensing electrical coupling between said first free-moving portion and said conductive charge member layer that occurs, at least in part, based on said interaction of said first and second charges.    
     
     
         83 . The method of  claim 82  wherein said nanometer-scale beam is provided as a nanotube.  
     
     
         84 . The method of  claim 82  wherein said nanometer-scale beam is provided with a second free-moving portion and said fixed portion is located between said first and second free-moving portions.  
     
     
         85 . The method of  claim 82  further comprising sensing the rate of contact between said first free-moving portion and said first conductive layer.  
     
     
         86 . The method of  claim 82  further comprising: 
 providing a second conductive layer in the proximity of said free-moving portion; and  
 sensing said first charge on said second conductive layer.  
 
     
     
         87 . The method of  claim 82  further comprising: 
 providing said first charge in a polarity opposite that of the polarity of said second charge.  
 
     
     
         88 . The method of  claim 82  further comprising: 
 providing said first charge in the polarity as the polarity of said second charge.  
 
     
     
         89 . The method of  claim 82  further comprising: 
 adjusting the intensity of said first charge resulting in an increased rate of contact between said nanometer-scale beam and said first conductive layer.  
 
     
     
         90 . The method of  claim 82  further comprising: 
 adjusting the intensity of said second charge resulting in an increased rate of contact between said nanometer-scale beam and said first conductive layer.  
 
     
     
         91 . The method of  claim 82  further comprising: 
 adjusting the rate of contact between said nanometer-scale beam and said first conductive layer by providing light on said nanometer-scale beam.  
 
     
     
         92 . A nanoelectromechanical system comprising: 
 a base member;    a first electrical contact;    a second electrical contact;    a first nanometer-scale beam fixed to said base member, wherein said first beam has a first portion that is free-to-move and said first beam is coupled to said first electrical contact; and    a second nanometer-scale beam fixed to said base, wherein said second beam is provided in the proximity of said first nanometer-scale beam, said second beam has a second portion that is free-to-move, and said second beam is electrically coupled to said second electrical contact.    
     
     
         93 . The system of  claim 92  wherein second beam is fixed at both ends and said second free-moving portion is located between said both ends.  
     
     
         94 . The system of  claim 92  wherein said first nanometer-scale beam is a nanotube and said second nanometer-scale beam is a nanotube.  
     
     
         95 . The system of  claim 92  further comprising: 
 a charge member located in the proximity of said first free-moving portion, wherein said first nanometer-scale beam has first charge, said charge member has a second charge, and said first and second charges interact to affect the distance between said first free-moving portion and said charge member.  
 
     
     
         96 . The system of  claim 92  further comprising: 
 a charge member located in the proximity of said first free-moving portion, wherein said first nanometer-scale beam has first charge, said charge member has a second charge, and said first and second charges interact to affect the distance between said first free-moving portion and said second free-moving portion.  
 
     
     
         97 . The system of  claim 92  further comprising: 
 a charge containment layer located in the proximity of said first free-moving portion, wherein said first nanometer-scale beam has first charge, said charge containment layer has a second charge, and said first and second charges interact to affect the motion of said first free-moving portion.  
 
     
     
         98 . The system of  claim 92 , wherein said second free-moving portion is substantially perpendicular to said first free-moving portion.  
     
     
         99 . A nanoelectromechanical system comprising: 
 a base member;    a mounting assembly attached to said base member;    a first nanometer-scale beam fixed to said base member, wherein said first beam has a first portion that is free-to-move;    a second nanometer-scale beam fixed to said base member, wherein said second beam has a second portion that is free-to-move; and    a first electrical contact coupled to said second nanometer-scale beam and placed in the proximity of said first free-moving portion.    
     
     
         100 . A nanoelectromechanical system comprising: 
 a base member;    a mounting assembly attached to said base member;    a first nanometer-scale beam fixed to said base member, wherein said first beam has a first portion that is free-to-move;    a second nanometer-scale beam fixed to said base member, wherein said second beam has a second portion that is free-to-move; and    a first electrical contact placed in the proximity of both said first free-moving portion and said second free-moving portion.    
     
     
         101 . A nanoelectromechanical system comprising: 
 a base member;    a first conductive mounting assembly attached to said base member;    a second mounting assembly attached to said base member;    a first nanometer-scale beam having a first end, a second end, and a first portion that is free-to-move, wherein said first end is coupled to said first conductive mounting assembly, and said second end is coupled to said second mounting assembly; and    a sense contact placed in the proximity of said first free-moving portion.    
     
     
         102 . The nanoelectromechanical system of  claim 101 , wherein said second mounting assembly is non-conductive.  
     
     
         103 . The nanoelectromechanical system of  claim 101  further comprising: 
 a charge member layer placed in the proximity of said first free-moving portion, wherein said charge member layer is provided a first charge, said first beam is provided a second charge, and said first and second charges electrically interact.  
 
     
     
         104 . The nanoelectromechanical system of  claim 103 , wherein said first beam is a nanotube.