Electrostatic graphene speaker
View Patent ↗This disclosure provides systems, methods, and apparatus associated with an electrostatically driven graphene speaker. In one aspect, a device includes a graphene membrane, a first frame on a first side of the graphene membrane, and a second frame on a second side of the graphene membrane. The first frame and the second frame both include substantially circular open regions that define a substantially circular portion of the graphene membrane. A first electrode is proximate the first side of the circular portion of the graphene membrane. A second electrode proximate the second side of the circular portion of the graphene membrane.
1. A device comprising:
a graphene membrane having a diameter of about 5 millimeters to 9 millimeters;
a first electrode proximate a first side of the graphene membrane, the first electrode being electrically conductive and having a first oxide layer disposed thereon; and
a second electrode proximate a second side of the graphene membrane, the second electrode being electrically conductive and having a second oxide layer disposed thereon, the graphene membrane being suspended between the first electrode and the second electrode,
wherein the device is a microphone.
2. The device of claim 1 , further comprising:
a first frame disposed on the first side of the graphene membrane;
a second frame disposed on the second side of the graphene membrane, the first frame and the second frame both including substantially circular open regions that define a substantially circular portion of the graphene membrane; and
a wire in electrical contact with the graphene membrane.
3. The device of claim 2 , wherein the first frame and the second frame are about 60 microns to 180 microns thick.
4. The device of claim 2 , wherein the first electrode is in contact with the first frame, wherein the first electrode is spaced a first distance of about 60 microns to 180 microns from the first side of the circular portion of the graphene membrane, wherein the second electrode is in contact with the second frame, and wherein the second electrode is spaced a second distance of about 60 microns to 180 microns from the second side of the circular portion of the graphene membrane.
5. The device of claim 2 , wherein the first frame and the second frame are a unitary body.
6. The device of claim 2 , wherein the wire is a gold wire with a diameter of about 10 microns to 30 microns.
7. The device of claim 1 , wherein the graphene membrane is about 20 nanometers to 40 nanometers thick.
8. The device of claim 1 , wherein the first electrode and the second electrode define open regions having a dimension of about 200 microns to 300 microns.
9. The device of claim 1 , wherein the first electrode and the second electrode include silicon wafers.
10. The device of claim 1 , wherein the device is configured to have a frequency response across a frequency range at least from 20 Hz to 20 kHz or across the entire human audible frequency range.
11. A condenser microphone comprising:
a graphene membrane;
a first electrode proximate a first side of the graphene membrane, the first electrode being electrically conductive and having a first oxide layer disposed thereon; and
a second electrode proximate a second side of the graphene membrane, the second electrode being electrically conductive and having a second oxide layer disposed thereon, the graphene membrane being suspended between the first electrode and the second electrode,
wherein the condenser microphone is configured to have a frequency response across a frequency range at least from 20 Hz to 20 kHz or across the entire human audible frequency range.
12. The condenser microphone of claim 11 , wherein the graphene membrane is a monolayer graphene membrane.
13. The condenser microphone of claim 11 , wherein the graphene membrane is about 20 nanometers to 40 nanometers thick.
14. The condenser microphone of claim 11 , wherein the graphene membrane is a multilayer graphene membrane.
15. A method comprising:
(a) providing a device including:
a graphene membrane;
a first electrode proximate a first side of the graphene membrane, the first electrode being electrically conductive and having a first oxide layer disposed thereon; and
a second electrode proximate a second side of the graphene membrane, the second electrode being electrically conductive and having a second oxide layer disposed thereon, the graphene membrane being suspended between the first electrode and the second electrode;
(b) biasing the graphene membrane with a direct current voltage;
(c) receiving a sound wave which causes the graphene membrane to vibrate;
(d) measuring the frequency and/or the amplitude of the sound wave by measuring an output signal generated at the first electrode and/or the second electrode;
wherein the device is configured to have a frequency response at least from 20 Hz to 20 kHz or across the entire human audible frequency range.
16. The method of claim 15 , wherein the output signal is digitally recorded as an audio signal.
17. The method of claim 15 , wherein the direct current voltage is about 50 volts to 150 volts or wherein an amplitude of the output signal is about 0 volts to 15 volts.
18. The method of claim 15 , wherein the first electrode and the second electrode are biased at opposite polarities.
19. The method of claim 15 , wherein the device further comprises:
a first frame disposed on the first side of the graphene membrane;
a second frame disposed on the second side of the graphene membrane, the first frame and the second frame both including substantially circular open regions that define a substantially circular portion of the graphene membrane; and
a wire in electrical contact with the graphene membrane.
20. The method of claim 15 , wherein the graphene membrane is about 20 nanometers to 40 nanometers thick.