Nano- and micro-electromechanical resonators

Patent metadata

Field	Value
Publication number	US-9419583-B2
Application number	US-201514969948-A
Country	US
Kind code	B2
Filing date	Dec 15, 2015
Priority date	Apr 22, 2013
Publication date	Aug 16, 2016
Grant date	Aug 16, 2016

Abstract

A resonator includes a piezoelectric plate and interdigitated electrode(s). The interdigitated electrode includes a plurality of conductive strips disposed over a top surface of the piezoelectric plate. A two-dimensional mode of mechanical vibration is excited in a cross sectional plane of the piezoelectric plate in response to an alternating voltage applied through the interdigitated electrode. The two-dimensional mode of mechanical vibration is a cross-sectional Lamé mode resonance (CLMR) or a degenerate cross-sectional Lamé mode resonance (dCLMR).

First claim

What is claimed:

1. A resonator comprising:
a piezoelectric plate having a length direction, a width direction, and a thickness direction; and
a first interdigitated electrode including a plurality of conductive strips disposed over a top surface of the piezoelectric plate, wherein the top surface extends along the length direction and the width direction, wherein each conductive strip has an electrode width substantially along the width direction, and wherein the plurality conductive strips are arranged with a pitch substantially along the width direction,
wherein a two-dimensional mode of mechanical vibration is excited in a cross sectional plane of the piezoelectric plate in response to an alternating voltage applied through the first interdigitated electrode, and wherein the cross sectional plane extends along the width direction and the thickness direction.

2. The resonator of claim 1 , wherein the two-dimensional mode of mechanical vibration is a cross-sectional Lamé mode of vibration in which a peak-to-peak displacement along the width direction is the same as a peak-to-peak displacement along the thickness direction.

3. The resonator of claim 2 , wherein a ratio of the pitch to a thickness of the piezoelectric satisfies:

p

T
AlN

=

(

C
11

-

C
55

)

(

C
33

-

C
55

)

,

wherein p is the pitch, T AlN is the thickness of the piezoelectric plate, and C ij are components of a stiffness matrix of the piezoelectric plate.

4. The resonator of claim 1 , wherein the two-dimensional mode of mechanical vibration is a degenerate cross-sectional Lamé mode of vibration in which a peak-to-peak displacement along the width direction is different from a peak-to-peak displacement along the thickness direction.

5. The resonator of claim 1 , further comprising a second interdigitated electrode including a plurality of conductive strips disposed over a bottom surface of the piezoelectric plate, wherein the bottom surface extends along the length direction and the width direction, wherein the two-dimensional mode of mechanical vibration is excited in the cross sectional plane in response to the alternating voltage applied through the first interdigitated electrode and the second interdigitated electrode.

6. The resonator of claim 1 , wherein the piezoelectric plate includes at least one of aluminum nitride, lithium niobate, lithium tantalate, zinc oxide, gallium nitride, scandium nitride, and quartz.

7. The resonator of claim 1 , wherein a thickness of the piezoelectric plate is in a range of about 50 nm to about 100 μm.

8. The resonator of claim 1 , wherein the pitch is in a range of about 50 nm to about 100 μm.

9. The resonance of claim 1 , wherein a ratio of the electrode width to the pitch is so configured as to achieve a maximum electromechanical coupling coefficient for the resonator.

10. The resonator of claim 1 , wherein a frequency of the two-dimensional mechanical mode of vibration is in a range of about 1 MHz to about 100 GHz.

11. The resonator of claim 1 , wherein the first interdigitated electrode is not in direct contact with the top surface of the piezoelectric plate.

12. The resonator of claim 11 , further comprising a temperature compensation layer disposed between the first interdigitated electrode and the top surface of the piezoelectric plate.

13. A infrared (IR) detector comprising:
a plasmonic piezoelectric resonator comprising:
a piezoelectric plate;
an interdigitated electrode including a plurality of conductive strips disposed over a bottom surface of the piezoelectric plate, wherein the plurality conductive strips are arranged with a pitch; and
a nanoplasmonic metasurface disposed over a top surface of the piezoelectric plate, wherein the nanoplasmonic metasurface has a pattern arranged to facilitate selective absorption of infrared (IR).

14. The IR detector of claim 13 , further comprising two tethers supporting the plasmonic piezoelectric resonator and electrically connecting to the interdigitated electrode.

15. The IR detector of claim 13 , wherein the piezoelectric plate includes at least one of aluminum nitride (AlN), gallium nitride (GaN), zinc oxide (ZnO), quartz, lithium niobate, and lithium tantalite.

16. The IR detector of claim 13 , wherein a thickness of the piezoelectric plate is in a range of about 10 nm to about 6 μm.

17. The IR detector of claim 13 , wherein a mode of mechanical vibration is excited in the piezoelectric plate in response to an alternating voltage applied through the first interdigitated electrode.

18. The IR detector of claim 17 , wherein a frequency of the mode of mechanical vibration shifts in response to absorption of the infrared (IR) by the piezoelectric plate.

19. The plasmonic piezoelectric resonator of claim 13 , wherein the pattern of the nanoplasmonic metasurface includes a plurality of unit cells.

20. A gravimetric sensor comprising:
a nano-scale resonator comprising:
a piezoelectric nano-plate with a thickness in a range of about 10 nm to about 6 μm; and
a first interdigitated electrode disposed over a top surface of the piezoelectric nano-plate, the first interdigitated electrode including a plurality of nano-strips arranged with a pitch in a range of about 10 nm to about 6 μm,

wherein a two dimensional mode of mechanical vibration is excited in the piezoelectric nano-plate in response to an alternating voltage applied through the first interdigitated electrode, and wherein a resonance frequency of the vibration shifts in response to mass loaded on the piezoelectric nano-plate.

21. The gravimetric sensor of claim 20 , further comprising single walled carbon nanotubes (SWNTs) grown on the nano-scale resonator.

22. The gravimetric sensor of claim 21 , wherein the SWNTs are decorated with single stranded DNAs.

23. The gravimetric sensor of claim 21 , further comprising a two dimensional material disposed on the top surface of the piezoelectric nano-plate.

24. The gravimetric sensor of claim 23 , wherein the two dimensional material includes at least one of graphene and molybdenum disulfide.

25. The gravimetric sensor of claim 20 , further comprising a second interdigitated electrode including a plurality of conductive strips disposed over a bottom surface of the piezoelectric nano-plate, wherein the two-dimensional mode of mechanical vibration

Assignees

• Univ Northeastern

Inventors

• Rinaldi Matteo
• Cassella Cristian
• Qian Zhenyun
• Hui Yu

Classifications

• G01J5/20

  using resistors, thermistors or semiconductors sensitive to radiation, e.g. photoconductive devices · CPC title

• H03H9/13

  for networks consisting of piezoelectric or electrostrictive materials (for networks using surface acoustic waves H03H9/145) · CPC title

• G01J5/58

  using absorption; using extinction effect · CPC title

• H03H9/15

  Constructional features of resonators consisting of piezoelectric or electrostrictive material (H03H9/25 takes precedence) · CPC title

• H03H9/02244 Primary

  of microelectro-mechanical resonators · CPC title