SENSOR SYSTEM AND METHOD EMPLOYING SHARED TRANSDUCER ELEMENTS

• US 20040149040A1
• Filed: 01/31/2003
• Published: 08/05/2004
• Est. Priority Date: 01/31/2003
• Status: Active Grant

• Current Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Original Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Inventors: Blakley, Daniel Robert
• Granted Patent: US 6,813,928 B2
• Time in Patent Office: Days
• US Class Current: 73/627
• CPC Class Codes: G01N 2291/014 Resonance or resonant frequency
• CPC Class Codes: G01N 2291/015 Attenuation, scattering
• CPC Class Codes: G01N 2291/0423 Surface waves, e.g. Rayleigh waves, Love waves
• CPC Class Codes: G01N 2291/0426 Bulk waves, e.g. quartz crystal microbalance, torsional waves
• CPC Class Codes: G01N 2291/102 one emitter, one receiver
• CPC Class Codes: G01N 29/022 Fluid sensors based on microsensors, e.g. quartz crystal-microbalance [QCM], surface acoustic wave [SAW] devices, tuning forks, cantilevers, flexural plate wave [FPW] devices microdevices per se B81B
• CPC Class Codes: G01N 29/24 Probes transducers for acoustic waves B06B, G10K; for measuring G01H
• CPC Class Codes: G01N 29/42 by frequency filtering or by tuning to resonant frequency

Abstract

A transducer-based sensor system including a first transducer system and a second transducer system spaced from the first transducer system so as to define a sample area between the first transducer system and the second transducer system where the first transducer system and second transducer system are collectively configured to transmit surface acoustic waves in multiple directions through the sample area and receive such surface acoustic waves.

Claims

1. A transducer-based sensor system, comprising:

a central transducer system;

a peripheral transducer system disposed radially about the central transducer system; and

a sample area at least partially surrounding the central transducer system and disposed between the central transducer system and the peripheral transducer system,

where the central transducer system and peripheral transducer system are collectively configured to transmit surface acoustic waves radially through the sample area and receive such surface acoustic waves.

2. The system of claim 1, where the central transducer system includes a shared transducer element and the peripheral transducer system includes N distributed transducer elements, where the shared transducer element and distributed transducer elements are positioned so as to define N sampling locations within the sample area, each sampling location being disposed between the shared transducer element and one of the distributed transducer elements.

3. The system of claim 2, where the shared transducer element is a transmitter element configured to transmit surface acoustic waves outward toward the peripheral transducer system, and where the distributed transducer elements are receiver elements configured to receive such surface acoustic waves.

4. The system of claim 2, where the distributed transducer elements are transmitter elements configured to transmit surface acoustic waves inward toward the central transducer system, and where the shared transducer element is a receiver element configured to receive such surface acoustic waves.

5. The system of claim 4, further comprising a drive signal generator coupled with the transmitter elements and configured to drive the transmitter elements, where the drive signal generator is configured to simultaneously apply different drive signals to each of the transmitter elements.

6. The system of claim 5, where the different drive signals are variants of a base oscillator signal.

7. The system of claim 6, where the peripheral transducer system includes four transmitter elements, and where the drive signal generator is configured to simultaneously drive the four transmitter elements with oscillatory signals shifted in phase from the base oscillator signal by 0°

, 90°

, 180° and

270°

, respectively.

8. The system of claim 5, further comprising an output processing subsystem operatively coupled with the receiver element, where the output processing subsystem is configured to process output received from the receiver element and, during such processing, use the different drive signals from the drive signal generator to synchronously detect individual output signals for the N sampling locations.

9. The system of claim 2, further comprising an output processing subsystem operatively coupled to at least one of the transducer elements, where the output processing subsystem is configured to extract, using synchronous detection, individual output signals corresponding to each of the N sampling locations.

10. The system of claim 9, further comprising a drive signal generator coupled to at least one of the transducer elements, where the drive signal generator is configured to apply N different drive signals to the at least one of the transducer elements, so as to cause surface acoustic waves to propagate through the sample area, and where each of the N different drive signals corresponds to a selected one of the N sampling locations and is used to synchronously detect output for the corresponding sample location.

11. The system of claim 10, where the N different drive signals are phase-shifted variants of a base oscillator signal.

12. The system of claim 2, where each of the transducer elements includes arcuate electrodes with piezoelectric material disposed between the arcuate electrodes.

13. A transducer-based sensor system, comprising a surface acoustic wave device, including:

a shared transducer element; and

N distributed transducer elements, where the shared transducer element and distributed transducer elements are positioned so as to define N sampling locations configured to accommodate passage of surface acoustic waves therethrough, each sampling location being disposed between the shared transducer element and one of the distributed transducer elements;

a drive signal generator coupled to the surface acoustic wave device, where the drive signal generator is configured to apply drive signals to the surface acoustic wave device in order to produce surface acoustic waves within the surface acoustic wave device; and

an output processing subsystem coupled to the surface acoustic wave device, where the output processing subsystem is configured to employ synchronous detection to selectively obtain individual output signals corresponding to each of the N sampling locations.

14. The system of claim 13, where the surface acoustic wave device has a non-radial configuration.

15. The system of claim 13, where the surface acoustic wave device has a radial configuration, in which the N distributed transducer elements are radially distributed about the shared transducer element, which is positioned in a central location.

16. The system of claim 15, where the shared transducer element is a transmitter element and the N distributed transducer elements are receiver elements, such that the shared transducer element is configured to transmit surface acoustic waves outward toward the N distributed transducer elements so that such surface acoustic waves impinge upon the N distributed transducer elements.

17. The system of claim 15, where the shared transducer element is a receiver element and the N distributed transducer elements are transmitter elements, such that the N distributed transducer elements are configured to transmit surface acoustic waves inward toward the shared transducer element so that such surface acoustic waves impinge upon the shared transducer element.

18. The system of claim 17, where the drive signal generator is configured to simultaneously apply different drive signals to each of the transmitter elements.

19. The system of claim 18, where the different drive signals are variants of a base oscillator signal.

20. The system of claim 19, where the N distributed transducer elements include four transmitter elements, and where the drive signal generator is configured to simultaneously drive the four transmitter elements with oscillatory signals shifted in phase from the base oscillator signal by 0°

, 90°

, 180° and

270°

, respectively.

21. The system of claim 18, where the output processing subsystem is configured to process output received from the receiver element and, during such processing, use the different drive signals from the drive signal generator to synchronously detect individual output signals for the N sampling locations.

22. The system of claim 15, where each of the transducer elements includes arcuate electrodes with piezoelectric material disposed between the arcuate electrodes.

23. A transducer-based method for obtaining data from a sample using surface acoustic wave technology, the method comprising:

applying drive signals to a surface acoustic wave device having a plurality of transducer elements, where such transducer elements include;

a shared transducer element; and

N distributed transducer elements, where the shared transducer element and distributed transducer elements are positioned so as to define N sampling locations adapted to accommodate passage of surface acoustic waves therethrough, each sampling location being disposed between the shared transducer element and one of the distributed transducer elements;

producing surface acoustic waves in response to the drive signals so that the surface acoustic waves propagate through the sampling locations;

receiving output from the surface acoustic wave device, where such output arises from the surface acoustic waves impinging upon at least one of the transducer elements within the surface acoustic wave device; and

employing synchronous detection in connection with the output received from the surface acoustic wave device, in order to obtain individual output signals corresponding to each of the N sampling locations.

24. The method of claim 23, where applying drive signals to the surface acoustic wave device includes applying a different drive signal for each of the N sampling locations.

25. The method of claim 24, where employing synchronous detection includes, for a given one of the N sampling locations, using the drive signal corresponding to such sampling location to synchronously detect the individual output signal corresponding to such sampling location.

26. A transducer-based sensor system, comprising a surface acoustic wave device, including:

a shared transducer means; and

N distributed transducer means, where the shared transducer means and distributed transducer means are positioned so as to define N sampling locations configured to accommodate passage of surface acoustic waves therethrough, each sampling location being disposed between the shared transducer means and one of the distributed transducer means;

drive signal generator means for applying drive signals to the surface acoustic wave device so as to produce surface acoustic waves within the surface acoustic wave device; and

an output processing subsystem coupled to the surface acoustic wave device, where the output processing subsystem includes means for employing synchronous detection to selectively obtain individual output signals corresponding to each of the N sampling locations.

27. A transducer-based sensor system, comprising:

a first transducer system; and

a second transducer system spaced from the first transducer system so as to define a sample area between the first transducer system and the second transducer system,

where the first transducer system and second transducer system are collectively configured to transmit surface acoustic waves in multiple directions through the sample area and receive such surface acoustic waves.

28. The transducer-based sensor system of claim 27, where the first transducer system is centrally positioned, and where the second transducer system is disposed in a peripheral configuration about the central transducer system.

29. The transducer-based sensor system of claim 28, where the first and second transducer systems are configured to transmit surface acoustic waves radially through the sample area and receive such surface acoustic waves.