Membrane-based nano-electromechanical systems device and methods to make and use same
Nano-electromechanical systems (NEMS) devices that utilize thin electrically conductive membranes, which can be, for example, graphene membranes. The membrane-based NEMS devices can be used as sensors, electrical relays, adjustable angle mirror devices, variable impedance devices, and devices performing other functions. The NEMS devices have a serpentine shape arrangement of the electrically conductive membrane. The electrically conductive membrane can be controllably wicked down on the edge of the oxide cavity to increase sensitivity of the NEMS device.
1. A nano-electromechanical systems device comprising a magnetic field sensor that comprises an electrically conductive membrane trough chip section that is oriented along a first plane, wherein the electrically conductive membrane trough section comprises
(a) a thin, electrically conductive membrane in a serpentine shape arrangement having a first end and a second end,
(b) a substrate having a non-conductive layer oriented parallel to the first plane, wherein
(i) the non-conductive layer comprises a plurality of cavities exposing one or more metal traces on the substrate,
(ii) the thin, electrically conductive membrane is on the non-conductive layer parallel to the first plane such that, due to the serpentine shape arrangement, the thin, electrically conductive membrane bounds the plurality of cavities and provides for a plurality of portions of the thin, electrically conductive membrane to face the one or more metal traces in the plurality of cavities, and
(iii) the thin, electrically conductive membrane is wicked down on the edge of each of the plurality of cavities;
(c) a first connector electrically connected to the first end of the serpentine shape arrangement; and
(d) a second connector electrically connected to the second end of the serpentine shape arrangement, such that current is operable to flow through the thin, electrically conductive membrane between the first connector and the second connector causing each of the portions of the thin, electrically conductive membrane facing the plurality of cavities to deflect in a direction perpendicular to the first plane in the presence of a magnetic field, wherein
(i) the magnetic field sensor is operable for sensing the magnetic field based upon sensing of changes of capacitance between the membrane and the one or traces in each of the plurality of cavities due to the deflection of the membrane facing the plurality of cavities.
2. The nano-electromechanical systems device of claim 1 , wherein the thin, electrically conductive membrane has a thickness of approximately one nm.
3. The nano-electromechanical systems device of claim 1 , wherein the thin, electrically conductive membrane has a thickness between 1 nm and 25 nm.
4. The nano-electromechanical systems device of claim 1 , wherein the thin, electrically conductive membrane is selected from a group consisting of graphene, graphene oxide, graphene/graphene oxide composites, and electrically conductive polymers.
5. The nano-electromechanical systems device of claim 1 , wherein the thin, electrically conductive membrane is one layer of graphene.
6. The nano-electromechanical systems device of claim 1 , wherein the thin, electrically conductive membrane comprises multiple layers of graphene.
7. The nano-electromechanical systems device of claim 1 , wherein the thin, electrically conductive membrane comprises PDMS coated with an electrically conductive material.
8. The nano-electromechanical systems device of claim 1 , wherein the plurality of cavities are arranged in a plurality of rows.
9. The nano-electromechanical systems device of claim 8 , wherein
(a) the plurality of rows comprises a first portion of the plurality of rows and a second portion of the plurality of rows; and
(b) the deflection of the portions of the thin, electrically conductive membrane in a direction perpendicular to the first plane comprises
(i) a first set of deflections in which the portions of the thin, electrically conductive membrane facing the first portions of plurality of rows deflect in a direction toward the substrate and the portions of the thin, electrically conductive membrane facing the second portions of rows deflect in a direction away from the substrate, and
(ii) a second set of deflections in in which the portions of the thin, electrically conductive membrane facing the first portions of plurality of rows deflect in the direction away from the substrate and the portions of the thin, electrically conductive membrane facing the second portions of rows deflect in the direction toward the substrate.
10. The nano-electromechanical systems device of claim 9 , wherein the deflections of the portions of the thin, electrically conductive membrane covering the plurality of cavities in adjacent rows in the plurality of rows deflect in an equal magnitude and opposite direction.
11. The nano-electromechanical systems device of claim 1 , wherein
(a) the nano-electromechanical systems device comprises two electrically conductive membrane trough chip sections, and
(b) the two electrically conductive membrane trough chip sections are perpendicular to one another.
12. The nano-electromechanical systems device of claim 1 , wherein
(a) the nano-electromechanical systems device comprises three electrically conductive membrane trough chip sections, and
(b) the three electrically conductive membrane trough chip sections are each perpendicular to one another.
13. The nano-electromechanical systems device of claim 1 , wherein the nano-electromechanical systems device is selected from a group consisting of membrane-based NEMS sensors, membrane-based magnetometers, and combinations thereof.
14. The nano-electromechanical systems device of claim 1 , wherein the nano-electromechanical systems device of claim 1 is operable to sense an alternating magnetic field signal.
15. The nano-electromechanical systems device of claim 14 , wherein the alternating magnetic field signal is between 1 and 100 femto-tesla.
16. The nano-electromechanical systems device of claim 1 , wherein the thin, electrically conductive membrane faces the one or more metal traces in the plurality of cavities at a gap distance of between 5 and 50 nm.
17. The nano-electromechanical systems device of claim 1 , wherein the substrate is a Si wafer.
18. The nano-electromechanical systems device of claim 1 , wherein the non-conductive layer is an oxide layer.
19. An apparatus comprising a nano-electromechanical systems device of claim 1 .
20. The apparatus of claim 19 , wherein the apparatus is selected from a group consisting of microphones, magnetometers, NEMS sensors, and combinations thereof.
21. A method comprising:
(a) selecting an apparatus comprising a nano-electromechanical systems device of claim 1 ; and
(b) utilizing the nano-electromechanical systems device in the apparatus in a use selected from a group consisting of NEMS sensors, microphones, magnetometers, and combinations thereof.
22. The method of claim 21 , wherein the apparatus is selected from a group consisting of microphones, magnetometers, and combinations thereof.