Piezoelectric signal generator

• US 9,634,232 B2
• Filed: 09/14/2011
• Issued: 04/25/2017
• Est. Priority Date: 11/04/2010
• Status: Active Grant

• Current Assignee: Algra Holding AG
• Original Assignee: Algra Holding AG
• Inventors: Matter, Dieter, Meli, Louis Marcel, Sivasubramaniam, Venkatesh, Gartmann, Thomas, Hutzler, Markus, Kizhakenath, Abhilash
• Primary Examiner(s): Rosenau, Derek
• Application Number:
  US13/882,869
• Publication Number:
  US 20130249349A1
• Time in Patent Office: 2,050 Days
• Field of Search: 310318, 310330, 310338, 310339
• CPC Class Codes: H02N 2/18 producing electrical output from mechanical input, e.g. generators for measurement devices G01
• CPC Class Codes: H03K 17/964 Piezoelectric touch switches
• CPC Class Codes: H03K 2217/94089 Wireless transmission
• CPC Class Codes: H10N 30/30 with mechanical input and electrical output, e.g. functioning as generators or sensors
• CPC Class Codes: H10N 30/308 Membrane type

Abstract

The piezoelectric signal generator (10;30) includes at least one piezoelectric element (12;20) connected with an emitter (14;35) which is capable of generating, from a current (C) produced by actuation of the piezoelectric element, an electromagnetic signal (S) capable of being wirelessly received by a receiver (16;36) removed from the signal generator (10;30), the piezoelectric element (20;31) comprises a piezoceramic layer (241) attached to an electrically conducting carrier stratum (242); the piezoceramic layer adheres to the carrier stratum and both are held by a positioning layer (23) which has a thickness (T_P), and both are capable of a reversible deformation, predetermined by and limited to the thickness (T_P) of the positioning layer (23); further, the piezoelectric element (20;31) comprises a gap layer (26) for buffering the reversible deformation of the carrier stratum (242) with the adhering piezoceramic layer (241); the gap (29) has a thickness (T_G) such that T_G≦T_P.

Claims

1. A piezoelectric signal generator (10;

30) including at least one piezoelectric element (12;

20) operatively connected with an emitter (14;

35) for generating, from a current (C) produced by actuation of said at least one piezoelectric element, an electromagnetic signal (S) being wirelessly received by a receiver (16;

36) removed from said signal generator (10;

30);

wherein said at least one piezoelectric element (20;

31) comprises a piezoceramic layer (241) adhering to an electrically conducting carrier stratum (242), each of said piezoceramic layer (241) and said electrically conducting carrier stratum (242) being substantially planar, wherein the periphery of the piezoceramic layer (241) and of the electrically conducting carrier stratum (242) are each fixedly held by a positioning layer (23) having a thickness (T_P), thereby preventing movement of the periphery of the piezoceramic layer (241) and the electrically conducting carrier stratum (242) at the positioning layer (23);

said electrically conducting carrier stratum (242) together with said adhering piezoceramic layer (241) being configured for reversible deformation; and

said piezoelectric element (20;

31) comprising a gap layer (26) positioned next to the piezoceramic layer (241) adhering to the electrically conducting carrier stratum (242) for limiting said reversible deformation by means of a gap (29) having a thickness (T_G) such that T_G <

T_P.

2. The signal generator (10) according to claim 1 wherein said electrically conducting carrier stratum (242) is a metal disc (242) peripherally supported by said gap layer (26).

3. The signal generator (10) according to claim 1 wherein said electrically conducting carrier stratum (242) is a metal disc (242) peripherally supported by said gap layer (26) and wherein said electrically piezoceramic layer (241) and said carrier stratum (242) form a coherent unit (24) having a thickness substantially equal to the thickness (T_P) of the positioning layer (23).

4. The signal generator (10) according to claim 1 wherein the thickness (T_P) of the positioning layer is in the range of from about 0.1 mm to about 1 mm.

5. The signal generator (10) according to claim 1 wherein the thickness (T_G) of the gap (29) is in the range of from about 0.05 mm to about 0.5 mm.

6. The signal generator (10) according to claim 1 wherein said electrically conducting base stratum (15) is capable of said predetermined and limited deformation in response to a manual pressure in the range of from about 1 to about 20 Pa.

7. The signal generator (10) according to claim 1 wherein said piezoelectric element (20) is an integrally laminated structure comprising, in sequence, an overlay layer (21);

a first connector layer (22) adjacent said positioning layer (23) for contacting said piezoceramic layer (241);

a second connector layer (25) for contacting said electrically conducting carrier stratum (242);

said gap layer (26) being positioned between said second connector layer (25) and at least one base layer (27).

8. The signal generator (10) according to claim 1 wherein said electrically conducting carrier stratum (242) is a metal disc (242) peripherally supported by said gap layer (26) and wherein said metal disc (242) has an essentially circular shape, a diameter in the range of from about 10 mm to about 50 mm, and forming with said piezoceramic layer (241) a piezoelectric unit (24) having a thickness in the range of from about 0.1 mm to about 1.0 mm.

9. The signal generator (10) according to claim 1 wherein

(i) said electrically conducting carrier stratum (242) is a metal disc (242) peripherally supported by said gap layer (26),

(ii) said metal disc (242) has an essentially circular shape, a diameter in the range of from about 10 mm to about 50 mm, and forming with said piezoceramic layer (241) a piezoelectric unit (24) having a thickness in the range of from about 0.1mm to about 1.0 mm,

(iii) said thickness (T_P) of said positioning layer is essentially the same as that of piezoelectric unit (24), and

(iv) said gap (29) has an essentially circular shape and is co-centric with said circular disc, and wherein the diameter of said gap (29) is not greater than said diameter of said piezoelectric unit (24).

10. The signal generator (10) according to claim 1 wherein the thickness (T_P) of the positioning layer is in the range of from about 0.2 to about 0.5 mm.

11. The signal generator (10) according to claim 1 wherein the thickness (T_G) of the gap (29) is in the range of from about 0.1 to about 0.25 mm.

12. The signal generator (10) according to claim 1 wherein

(i) said electrically conducting carrier stratum (242) is a metal disc (242) peripherally supported by said gap layer (26),

(ii) said metal disc (242) has an essentially circular shape, a diameter in the range of from about 10 mm to about 50 mm, and forming with said piezoceramic layer (241) a piezoelectric unit (24) having a thickness in the range of from about 0.1mm to about 1.0 mm, and

(iii) said thickness (T_P) of said positioning layer is essentially the same as that of piezoelectric unit (24), and

(iv) said gap (29) has an essentially circular shape and is co-centric with said circular disc, and wherein the diameter of said gap (29) is smaller than said diameter of said piezoelectric unit (24) by about 0.5 mm to about 2.5 mm.

13. A signalling system comprising a receiver (16;

36) and a piezoelectric signal generator (10;

30) including at least one piezoelectric element (12;

20) operatively connected with an emitter (14;

35) for generating, from a current (C) produced by actuation of said at least one piezoelectric element, an electromagnetic signal (S) being wirelessly received by the receiver (16;

36) removed from said signal generator (10;

30), wherein said at least one piezoelectric element (20;

31) comprises a piezoceramic layer (241) adhering to an electrically conducting carrier stratum (242) each of said piezoceramic layer (241); and

said electrically conducting carrier stratum (242) being substantially planar, wherein the periphery of the piezoceramic layer (241) and of the electrically conducting carrier stratum (242) are each fixedly held by a positioning layer (23) having a thickness (T_P), thereby preventing movement of the periphery of the piezoceramic layer (241) and the electrically conducting carrier stratum (242) at the positioning layer (23);

said electrically conducting carrier stratum (242) together with said adhering piezoceramic layer (241) being configured for reversible deformation;

said piezoelectric element (20;

31) comprising a gap layer (26) positioned next to the piezoceramic layer (241) adhering to the electrically conducting carrier stratum (242) for limiting said reversible deformation by means of a gap (29) having a thickness (T_G) such that T_G ≦

T_P.

14. A piezoelectric signal generator comprising:

a piezoelectric element operatively connected with an emitter to generate, from a current produced through actuation of said piezoelectric element, an electromagnetic signal, the electromagnetic signal being wirelessly transmitted to a receiver situated remotely from said signal generator;

wherein said piezoelectric element includes a piezoceramic layer adhered to an electrically conducting carrier stratum, each of said piezoceramic layer and said electrically conducting carrier stratum being substantially planar;

wherein the periphery of the piezoceramic layer and of the electrically conducting carrier stratum are fixedly held by a positioning layer having a thickness (T_P), thereby preventing movement of the periphery of the piezoceramic layer and the electrically conducting carrier stratum at the positioning layer;

said electrically conducting carrier stratum, together with said adhered piezoceramic layer, being configured for reversible deformation; and

said piezoelectric element comprising a gap layer positioned adjacent the piezoceramic layer adhered to the electrically conducting carrier stratum for limiting said reversible deformation by means of a gap having a thickness (T_G) such that T_G ≦

T_P.

15. The piezoelectric signal generator of claim 14, wherein said electrically conducting carrier stratum is a metal disc peripherally supported by said gap layer.

16. The piezoelectric signal generator of claim 15, wherein said electrically piezoceramic layer and said carrier stratum form a coherent unit having a thickness substantially equal to the thickness (T_P) of the positioning layer.

17. The piezoelectric signal generator of claim 14, wherein said electrically conducting base stratum is capable of said predetermined and limited deformation in response to a pressure in the range of from about 1 Pa to about 20 Pa.

18. The piezoelectric signal generator of claim 14, wherein said piezoelectric element is an integrally laminated structure comprising, in sequence, an overlay layer;

a first connector layer adjacent said positioning layer for contacting said piezoceramic layer;

a second connector layer to contact said electrically conducting carrier stratum;

said gap layer being positioned between said second connector layer and at least one base layer.

19. The piezoelectric signal generator of claim 15, wherein said metal disc is substantially circular in shape, with a diameter in the range of from about 10 mm to about 50mm, and said metal disc forming with said piezoceramic layer a piezoelectric unit having a thickness in the range of from about 0.1 mm to about 1.0 mm.

20. The piezoelectric signal generator of claim 15, wherein

(i)said metal disc is substantially circular in shape, with a diameter in the range of from about 10 mm to about 50 mm, and said metal disc forming with said piezoceramic layer a piezoelectric unit having a thickness in the range of from about 0.1 mm to about 1.0 mm,

(ii) said thickness (T_P) of said positioning layer is substantially the same as that of piezoelectric unit, and

(iii) said gap is substantially circular shape and is co-centric with said metal disc, and wherein the diameter of said gap is not greater than said diameter of said piezoelectric unit.