Wireless sensing and communication utilizing RF transmissions from microdischarges

• US 9,083,392 B2
• Filed: 05/17/2005
• Issued: 07/14/2015
• Est. Priority Date: 05/17/2005
• Status: Expired due to Fees

• Current Assignee: Board of Regents of the University of Michigan (University of Michigan)
• Original Assignee: Board of Regents of the University of Michigan (University of Michigan)
• Inventors: Gianchandani, Yogesh B., Gharpurey, Ranjit, Eun, Christine K.
• Primary Examiner(s): Kumar, Pankaj
• Assistant Examiner(s): BROWN, RUEBEN M
• Application Number:
  US11/131,019
• Publication Number:
  US 20060264175A1
• Time in Patent Office: 3,710 Days
• Field of Search: 455/41.1, 313/582, 313/491, 313/104, 313/484, 313/538, 313/163, 313/243, 257/214, 257/288, 257/682, 372/20, 438/776, 315/102, 315/111.31, 343/582
• US Class Current: 1/1
• CPC Class Codes: H04B 5/73 for taking measurements, e.g. using sensing coils

Abstract

Disclosed herein are systems and devices capable of wireless communications based on RF transmissions from discharges. A transmitting device includes a discharge generator having a plurality of electrodes spaced to support generation of the discharge, and a circuit coupled to the plurality of spaced electrodes to control a supply for the discharge generator. In some embodiments, controlling the supply for the discharge generator modifies a property of the discharge to modulate the RF transmission such that the resulting RF transmission is indicative of the device state or other information to be communicated.

Claims

1. A system capable of RF communication, the system comprising:

a supply to produce an electrical supply signal;

a device coupled to the supply to receive the electrical supply signal and comprising a plurality of microfabricated electrodes spaced to generate an electrical microdischarge in a medium and in response to the supply signal, wherein the generated electrical microdischarge generates an RF transmission in response to variations in one or both of (i) the supply signal and (ii) characteristics of the medium; and

,

an antenna to receive the RF transmission from the electrical microdischarge to enable the RF communication,

wherein the microfabricated electrodes of the device form a sensor of the device, the sensor having a state such that the RF transmission generated by the electrical microdischarge is indicative of the sensor state, and wherein the sensor indicates whether a chemical species is present in the medium via a modification of a characteristic of the RF transmission resulting from an interaction between the electrical microdischarge and the chemical species.

2. The system of claim 1, wherein the sensor indicates whether a further chemical species is present via a further modification of the characteristic of the RF transmission resulting from an interaction between the electrical microdischarge and the further chemical species, and wherein the first-named and further modifications of the RF transmission characteristic are different.

3. The system of claim 1, wherein the plurality of microfabricated electrodes comprises an electrode pair and a high-impedance gate electrode having a voltage applied thereto to facilitate the electrical microdischarge between the electrode pair.

4. The system of claim 1, wherein the sensor comprises a structure comprising one of the microfabricated electrodes and having a position movable in response to an external force to be detected by the sensor.

5. The system of claim 4, wherein the structure comprises a suspended beam having a discharge tip such that the sensor comprises an accelerometer.

6. The system of claim 1, wherein the supply is a power source, the device further comprising a microdischarge generator comprising the plurality of microfabricated electrodes, and the sensor coupled to the power source and the microdischarge generator, such that a supply signal for the microdischarge generator is controlled by a transduction state of the sensor.

7. The system of claim 6, wherein the sensor comprises a passive element having a variable impedance to vary the supply for the microdischarge generator.

8. The system of claim 6, wherein the microdischarge generator comprises a boost converter coupled to the plurality of microfabricated electrodes.

9. The system of claim 1, wherein the device comprises one or more passive circuit elements coupled to the plurality of microfabricated electrodes to control the microdischarge for spectral shaping of the RF transmission.

10. The system of claim 1, further comprising a power detector coupled to the antenna.

11. The system of claim 1, further comprising a matched filter coupled to the antenna and configured to detect a predetermined pulse shape of the RF transmission.

12. The system of claim 1, wherein the device is one of an array of distributed devices of the system generating electrical microdischarges, wherein the antenna receives respective RF transmissions from the device array, and wherein the system further comprises a monitoring device coupled to the antenna to monitor the respective RF transmissions individually.

13. The system of claim 12, wherein each device of the plurality of devices comprises a micro-electro discharge machining apparatus to machine a respective workpiece such that the monitoring device analyzes the respective RF transmission to monitor operation of the micro-electro discharge machining apparatus.

14. A method of transmitting data from a device, the method comprising:

providing, from a supply, a supply signal indicative of the data to spaced microfabricated electrodes of the device to generate an electrical microdischarge between the spaced microfabricated electrodes;

generating, from the electrical microdischarge generated between the spaced microfabricated electrodes, an RF transmission, wherein the microfabricated electrodes of the device form a sensor, the sensor having a state such that the RF transmission generated by the electrical microdischarge is indicative of the sensor state in a medium;

modifying the supply signal to modify a property of the electrical microdischarge to modulate the RF transmission such that the RF transmission is indicative of the data, for being received by an antenna of an external device to enable RF communication between the device generating the RF transmission and the external device; and

sensing whether a chemical species is present in the medium via a modification of a characteristic of the RF transmission resulting from an interaction between the electrical microdischarge and the chemical species, the data indicating information on the chemical species.

15. The method of claim 14, wherein modifying the supply signal comprises controlling the supply for the electrical microdischarge based on a variable circuit element of a circuit of the device coupled to the spaced microfabricated electrodes.

16. The method of claim 15, wherein the variable circuit element is responsive to a condition external to the circuit such that the data is indicative of the condition.

17. The method of claim 14, wherein the supply signal comprises a frequency component indicative of the data.

18. The method of claim 14, wherein generating the RF transmission comprises superimposing a current signal during the electrical microdischarge.

19. The method of claim 14, wherein modifying the supply signal comprises controlling a noise signature of the electrical microdischarge such that the noise signature is indicative of the data.

20. The method of claim 14, further comprising:

receiving, at the antenna, the RF transmission from the electrical microdischarge; and

,

analyzing a frequency spectrum of the RF transmission to determine the data.

21. The method of claim 20, further comprising filtering the received RF transmission to improve a signal-to-noise ratio thereof.

22. The method of claim 21, wherein filtering the received RF transmission comprises utilizing a matched filter configured to detect a predetermined pulse shape.

23. A method of transmitting information from a device, the method comprising:

providing, from a supply, a supply signal to spaced microfabricated electrodes of the device;

generating, in response to changes in conditions between the space microfabricated electrodes, an electrical microdischarge between the spaced microfabricated electrodes of the device, wherein the microfabricated electrodes form a Geiger counter to detect whether a species is present, wherein the electrical microdischarge from the spaced microfabricated electrodes generates an RF transmission having a frequency spectrum dependent on the presence of the species ionized in the Geiger counter;

transmitting the generated RF transmission from the Geiger counter to a receiver;

receiving, at the receiver, the RF transmission resulting from the electrical microdischarge; and

,

analyzing the frequency spectrum of the RF transmission to determine the information.

24. The method of claim 23, wherein analyzing the frequency spectrum comprises detecting whether the frequency spectrum indicates that the species is present.

25. The method of claim 23, further comprising filtering the received RF transmission to improve a signal-to-noise ratio thereof.

26. The method of claim 25, wherein filtering the received RF transmission comprises utilizing a matched filter configured to detect a predetermined pulse shape.

27. The method of claim 23, wherein generating the electrical microdischarge comprises pre-filtering the RF transmission by modifying a property of the electrical microdischarge.

28. The method of claim 23, wherein generating the electrical microdischarge occurs in response to changes in the supply signal affecting changes in conditions between the spaced microfabricated electrodes.

29. The method of claim 23, wherein generating the electrical microdischarge occurs in response to introduction of the species between the spaced microfabricated electrodes.

30. The method of claim 23, wherein the species is a radioactive species.

31. A system capable of RF communication, the system comprising:

a supply to produce an electrical supply signal;

a device coupled to the supply to receive the electrical supply signal and comprising a plurality of microfabricated electrodes spaced to generate an electrical microdischarge in a medium and in response to the supply signal, wherein the generated electrical microdischarge generates an RF transmission in response to variations in one or both of (i) the supply signal and (ii) characteristics of the medium; and

,

an antenna to receive the RF transmission from the electrical microdischarge to enable the RF communication,

wherein the microfabricated electrodes of the device form a sensor of the device, the sensor having a state such that the RF transmission generated by the electrical microdischarge is indicative of the sensor state, and wherein the sensor state is responsive to a beta particle interaction with the sensor such that the RF transmission is indicative of whether a beta particle has been detected.