Molecular transistor driving of nanoscale actuators from differential amplifier circuits compatible with carbon nanotube sensors and transducers
View Patent ↗A carbon nanotube electronic circuit utilizing a differential amplifier is implemented on a single carbon nanotube. Field effect transistors are formed from a first group of electrical conductors in contact with the carbon nanotube and a second group of electrical conductors insulated from, but exerting electric fields on, the carbon nanotube form the gates of the field effect transistors. A signal input circuit has a first input portion and a second input portion. A first field effect transistor electrically responsive to a first incoming signal is formed on the first input portion. A carbon nanotube actuator having electrical terminals and responsive to electrical conditions is an electrical load. A current source, connected to the signal input circuit, is formed on the carbon nanotube from one or more second field effect transistors. The electrical load is connected to the signal input circuit, and the signal input circuit and current source together form a differential amplifier to operate the actuator responsive to the incoming signal.
1. An apparatus, comprising:
a carbon nanotube;
an actuator circuit formed using the carbon nanotube;
first and second transistors formed using the carbon nanotube and configured as a differential amplifier configured to operate the actuator circuit responsive to an input signal.
2. The apparatus of claim 1 , wherein each of the first and second transistors includes a respective gate terminal that is electrically insulated from the carbon nanotube and is configured to exert an electric field on the carbon nanotube.
3. The apparatus of claim 1 , wherein the first transistor forms a first input circuit responsive to an electrical input signal, and wherein the actuator circuit forms a second input circuit in a form of a sensor responsive to an incoming stimulus, and wherein the apparatus is configured to produce a differential output based on the electrical input signal and the incoming stimulus.
4. The apparatus of claim 3 , wherein the incoming stimulus is an optical signal.
5. The apparatus of claim 3 , wherein the incoming stimulus is a chemical reaction.
6. The apparatus of claim 3 , wherein the incoming stimulus is a temperature.
7. The apparatus of claim 3 , wherein the incoming stimulus is a gas pressure.
8. The apparatus of claim 3 , wherein the incoming stimulus is a contact pressure.
9. The apparatus of claim 1 , further comprising a third transistor coupled to the second transistor, wherein the third transistor is formed on the carbon nanotube, and wherein respective gate terminals of the second and third transistors are coupled to a power node.
10. The apparatus of claim 9 , further comprising a current source, wherein the current source includes a fourth transistor formed on the carbon nanotube.
11. The apparatus of claim 10 , wherein the first transistor and the actuator circuit are coupled to the fourth transistor.
12. The apparatus of claim 1 , wherein the actuator circuit includes a mechanical displacement transducer.
13. The apparatus of claim 1 , wherein the actuator circuit includes a nanoscale electromechanical relay.
14. The apparatus of claim 1 , wherein the actuator circuit includes a fluidic valve transducer.
15. A differential amplifier, comprising:
a first transistor implemented using a carbon nanotube; and
a second transistor implemented using the carbon nanotube;
wherein each of the first and second transistors includes a respective gate terminal electrically insulated from the carbon nanotube.
16. The differential amplifier of claim 15 , wherein the first transistor is configured to receive a first portion of a differential input signal on its respective gate terminal, and wherein the second transistor is configured to receive a second portion of a differential input signal on its respective gate terminal.
17. The differential amplifier of claim 15 , further comprising a third and fourth transistors implemented on the carbon nanotube, wherein each of the third and fourth transistors includes respective source and drain terminals in electrical contact with the carbon nanotube, and further include respective gate terminals electrically insulated from and configured to exert a respective electric field on the carbon nanotube.
18. The differential amplifier of claim 17 , wherein the third and fourth transistors are arranged to provide an active load for the differential amplifier.
19. The differential amplifier of claim 17 , wherein the third transistor is electrically coupled to the first transistor, and wherein the second transistor is electrically coupled to the fourth transistor.
20. The differential amplifier of claim 17 , further comprising a current source including a fifth transistor implemented on the carbon nanotube, wherein the fifth transistor is electrically coupled to the first and second transistors.
21. The differential amplifier of claim 20 , further comprising a resistor implemented on the carbon nanotube, wherein the resistor is coupled between the fifth transistor and a ground node.
22. An apparatus comprising:
a carbon nanotube;
first and second transistors implemented using the carbon nanotube, wherein each of the first and second transistors includes a respective gate terminal coupled to a power node;
a third transistor implemented using the carbon nanotube and electrically coupled to the first transistor, wherein the third transistor is configured to receive an electrical input signal;
an actuator implemented using the carbon nanotube, wherein the actuator is configured to respond to an incoming stimulus, wherein the actuator is electrically coupled to the second transistor; and
a fourth transistor implemented using the carbon nanotube, wherein the fourth transistor is electrically coupled the third transistor and the actuator;
wherein the apparatus is configured to generate a differential output signal based on the electrical input signal and the incoming stimulus.
23. The apparatus of claim 22 , wherein the fourth transistor is configured to act as a current source.
24. The apparatus of claim 22 , wherein the first and second transistors are configured to act as an active load.
25. The apparatus of claim 22 , wherein the incoming stimulus is an optical signal.
26. The apparatus of claim 22 , wherein the incoming stimulus is a temperature.
27. The apparatus of claim 22 , wherein the incoming stimulus is a gas pressure.
28. The apparatus of claim 22 , wherein the incoming stimulus is a contact pressure.