CN110460941B

CN110460941B - Transmitting-receiving integrated graphene acoustic sensor

Info

Publication number: CN110460941B
Application number: CN201910664270.5A
Authority: CN
Inventors: 郭新华; 安佳宝
Original assignee: Wuhan University of Technology WUT
Current assignee: Wuhan University of Technology WUT
Priority date: 2019-07-23
Filing date: 2019-07-23
Publication date: 2020-12-18
Anticipated expiration: 2039-07-23
Also published as: CN110460941A

Abstract

The invention designs a transmitting-receiving integrated graphene acoustic sensor, which comprises an upper polar plate, an electromagnetic coil and a lower polar plate which are sequentially arranged from top to bottom, wherein an insulating layer is arranged at the contact part of the upper polar plate, the lower polar plate and the electromagnetic coil, a graphene film layer is attached to the upper polar plate, the lower polar plate comprises a supporting plate and a copper substrate, the copper substrate is contacted with the insulating layer, the graphene acoustic sensor also comprises a sound receiving circuit and a sound transmitting circuit which are connected to the upper polar plate and the lower polar plate through a selection switch, the sound receiving circuit is connected to a direct-current stabilized voltage power supply, and a generated voltage signal is output through; the sound emitting circuit is connected in series with a direct current stabilized voltage power supply and an alternating current power supply, wherein the alternating current power supply is connected with an electromagnetic coil through an amplifier. The unique structural arrangement of the invention is matched with the receiving and transmitting integrated circuit, and the function of efficiently receiving and transmitting the sound signals is completely realized.

Description

Transmitting-receiving integrated graphene acoustic sensor

Technical Field

The invention relates to a high-performance transceiving integrated graphene acoustic sensor which can be applied to aspects of medical imaging, detection, electronic product communication and the like.

Background

An acoustic transducer is a transducer that can transduce acoustic signals into electrical signals. By using the acoustic sensor, the acoustic signal in nature can be received and converted into an electric signal, and further converted into other physical signals, such as an ultrasonic range finder; the electrical signal may also be converted to an acoustic signal, such as a speaker. An acoustic sensor that is currently widely used in the field of consumer electronics is a condenser microphone, which uses the principle of capacitance to fix a lower plate and make a vibratable membrane into an upper plate. The interelectrode voltage is guaranteed to be unchanged, when the film feels external sound waves, corresponding vibration can occur, then the film deviates from the original balance position, the distance between the two polar plates is changed, and the capacitance value is changed.

The condenser microphone has a good performance in receiving a sound signal, but it has a disadvantage in terms of sound emission. The excitation of the electrical signal to the upper polar plate (membrane) cannot be too large, so that the amplitude of the membrane is very small, and the converted sound signal cannot meet the requirement, so that the function of the capacitance microphone for receiving and transmitting the integrated sound signal is limited, and in addition, the current capacitance microphone cannot meet the requirements of some products in the aspect of frequency response due to the limitation of using membrane materials.

Disclosure of Invention

The invention provides a high-performance graphene acoustic sensor integrating receiving and transmitting, aiming at overcoming the defects of the prior art.

In order to achieve the purpose, the invention designs a graphene acoustic sensor integrating receiving and transmitting, which comprises an upper polar plate, an electromagnetic coil and a lower polar plate which are sequentially arranged from top to bottom, wherein the contact part of the upper polar plate and the lower polar plate with the electromagnetic coil is provided with an insulating layer, and a graphene film layer is attached to the upper polar plate, and the graphene acoustic sensor is characterized in that: the lower polar plate comprises a supporting plate and a copper substrate, the copper substrate is in contact with the insulating layer, the sound receiving circuit and the sound emitting circuit are connected to the upper polar plate and the lower polar plate through a selection switch, the sound receiving circuit is connected to the direct current stabilized voltage power supply, and a generated voltage signal is output through the amplifying circuit; the sound emitting circuit is connected in series with a direct current stabilized voltage power supply and an alternating current power supply, wherein the alternating current power supply is connected with an electromagnetic coil through an amplifier.

Furthermore, the sound receiving circuit and the sound emitting circuit share a direct current stabilized power supply, and the alternating current power supply is accessed by a selection switch.

Further, the radius of the graphene film layer is 1mm, and the thickness is 50 μm. The center frequency of the film can reach 520K Hz, and the frequency response bandwidth of the sensor can be improved.

Furthermore, the insulating layer is of an annular structure, the outer diameter of the insulating layer is equal to the radius of the graphene film, the inner diameter of the insulating layer is 0.6mm, the insulating layer is made of PVC resin, the structure can play a role in supporting insulation, the magnetic circuit can be prevented from being blocked, and the electromagnetic coil plays the greatest role.

Furthermore, the electromagnetic coil is composed of multiple turns of enameled wires with the same wire diameter, the whole electromagnetic coil is of an annular structure, the outer diameter of the annular structure is 1mm, the inner diameter of the annular structure is 0.4mm, and the thickness of the annular structure is 100 micrometers. After current is introduced into the annular electromagnetic coil, a stronger magnetic field can be generated in the coil, and the signal output of the sensor is improved.

Furthermore, the outer diameter of the support plate of the lower polar plate is 1mm, the thickness of the copper substrate is 50 μm, and the thickness of the support plate is 100 μm.

The invention utilizes the graphene film with high physical performance as the vibrating membrane, so that the acoustic sensor realizes wider frequency response, designs the receiving and transmitting integrated circuit, and can switch the receiving and transmitting state at any time.

Compared with the prior art, the invention has the following technical effects:

(1) the acoustic sensor can receive and transmit sound with high performance, adopts electromagnetic excitation, and has better effect than common condenser microphone in terms of sound production.

(2) The graphene film is used, so that the acoustic sensor can detect sound heard by human ears and can detect ultrasonic waves.

(3) The sensor can be used independently by combining related means, is used in the fields of electronic product communication, micro detection and the like, and can also be made into a sensor array for distance measurement, imaging, industrial nondestructive detection and the like.

Drawings

FIG. 1 is a layered view of the overall structure of the present invention;

FIG. 2 is a control flow chart of the present invention;

fig. 3 is a schematic diagram of the circuit of the present invention.

In the figure: the device comprises an upper polar plate 1, a substrate 1.1, a graphene film layer 1.2, an electromagnetic coil 2, an insulating layer 3, a lower polar plate 4, a copper polar plate 4.1 and a supporting plate 4.2.

Detailed Description

The invention will be further explained with reference to the drawings.

Referring to fig. 1, the invention relates to a high-performance transceiving integrated graphene film acoustic sensor, which comprises an upper polar plate 1, an electromagnetic coil 2, an insulating layer 3 and a lower polar plate 4, wherein the electromagnetic coil 2 is positioned between the upper polar plate 1 and the lower polar plate 4, and the insulating layer is arranged on the contact part of the electromagnetic coil 2 and the upper polar plate and the lower polar plate; the upper polar plate comprises a substrate 1.1 and a graphene film layer 1.2 attached to the substrate; the lower polar plate 4 is a copper polar plate 4.1 and a supporting plate 4.2, and corresponding signal amplifying circuit units are arranged below the supporting plate 4.2. In this embodiment, the substrate 1.1 is SiO₂The graphene film is 1mm in radius and 50 microns in thickness, and one corner of the graphene film can be connected with an external circuit; the insulating layer 3 is a ring with an outer diameter equal to the radius of the film and an inner diameter of 0.6mm and is made of PVC resinThe insulating and supporting functions can be realized. The first insulating layer is positioned between the upper polar plate and the electromagnetic coil, the second insulating layer is positioned between the electromagnetic coil 2 and the lower polar plate 4, the electromagnetic coil 2 is composed of a plurality of turns of enameled wires with the same wire diameter, and can be seen as a circular ring, the outer diameter is 1mm, the inner diameter is 0.4mm, and the thickness is 100 mu m. The lower polar plate is a copper substrate, the outer diameter of the copper substrate and the outer diameter of the supporting plate are 1mm, the thickness of the copper substrate is 50 micrometers, the thickness of the supporting plate is 4.2 micrometers, one corner of the copper substrate can be connected with an external circuit, and particularly, the lower polar plate is connected with a branch source cathode. The backup pad is the PCB board in this design.

Referring to fig. 2, when receiving a sound signal, the present invention is embodied as: the direct current constant voltage is applied between the upper polar plate and the lower polar plate, when the film is subjected to certain sound pressure, vibration is generated, the interelectrode distance is changed, the capacitance is changed, and an alternating signal can be generated because the voltage is not changed, and an electric signal meeting the requirement can be output through the amplifying circuit; when the sound signal is sent out, the following steps are implemented: direct current constant voltage and an alternating current signal are applied between the upper polar plate and the lower polar plate, the alternating current signal can generate an electromagnetic field when passing through the conductive graphene film, the alternating current signal is connected into the electromagnetic coil through the amplifying circuit, the alternating electromagnetic force is generated, the vertical amplitude of the film is increased, and a sound signal meeting the requirements is generated. The electromagnetic coil is insulated and made of copper and is wound in a spiral shape.

Fig. 3 is a schematic diagram of a circuit, in which the circuit is composed of a capacitor C, a resistor R1, a DC power supply DC, an AC power supply AC amplifier, an electromagnetic coil, a power switch S1, and a selection switch SPDT 1. The C capacitor represents an upper polar plate and a lower polar plate which are connected with the circuit, when the C capacitor is used for receiving a sound signal, S1 is closed, SPDT1 is dialed to 1, only a direct current voltage stabilization source DC is connected into the circuit, at the moment, the C capacitor changes, an alternating electric signal exists at a resistor R1, and the alternating electric signal can be output to the controller through an amplifier A1; when the electromagnetic wave transmitter is used for transmitting sound signals, S1 is closed, the SPDT1 is switched to 2, a direct current voltage stabilizing source DC and an alternating current power supply AC are connected into a circuit, the alternating current power supply AC sends out an alternating current signal, the signal enables an upper pole plate to vibrate through a capacitor C and generate electromagnetic force, and the alternating current signal is connected into an electromagnetic coil through an amplifier A2 and generates strong electromagnetic force. Therefore, the acoustic sensor interacts with the upper polar plate, so that the amplitude of the film is improved, a stronger sound signal is generated, and the whole acoustic sensor has the capabilities of receiving and transmitting the signal integrally and outputting the signal with high performance. Specifically, after an alternating current signal is introduced into the graphene film, a magnetic field can be generated, an amplified alternating current signal is introduced into the electromagnetic coil, periodic interaction force, attraction force or repulsion force can be generated between the graphene film and the electromagnetic coil in a signal period, and the film vibrates periodically at the moment due to the fixed position of the electromagnetic coil.

When the invention is applied, the signal output of the amplifying circuit unit A1 can be connected with a controller based on STM32, the controller can be used for monitoring the change of capacitance in real time, and the collected electric signal can be used for controlling an actuating mechanism after being processed when receiving sound. When the sensor produces sound, the output of the alternating current signal can be controlled, and the frequency and the sound pressure level of the sound produced by the sound sensor are further controlled to obtain the sound signal meeting the requirements.

Claims

1. The utility model provides a graphite alkene acoustic sensor of receiving and dispatching an organic whole, includes from last upper polar plate, solenoid and the bottom plate that arranges in proper order down, wherein with upper and lower polar plate and solenoid contact segment be equipped with the insulating layer, just the upper polar plate has attached to graphite alkene thin layer, its characterized in that: the lower polar plate comprises a supporting plate and a copper substrate, the copper substrate is in contact with the insulating layer, the sound receiving circuit and the sound emitting circuit are connected to the upper polar plate and the lower polar plate through a selection switch, the sound receiving circuit is connected to the direct current stabilized voltage power supply, and a generated voltage signal is output through the amplifying circuit; the sound emitting circuit is connected in series with a direct current stabilized voltage power supply and an alternating current power supply, wherein the alternating current power supply is connected with an electromagnetic coil through an amplifier.

2. The integrated graphene acoustic sensor according to claim 1, wherein: the sound receiving circuit and the sound emitting circuit share a direct current stabilized voltage power supply, and the alternating current power supply is accessed by a selection switch.

3. The integrated graphene acoustic sensor according to claim 1, wherein: the radius of the graphene film layer is 1mm, the thickness of the graphene film layer is 50 micrometers, the center frequency of the graphene film layer can reach 520K Hz, and the frequency response bandwidth of the sensor can be improved.

4. The integrated graphene acoustic sensor according to claim 1, wherein: the insulating layer is the loop configuration, and the external diameter equals with graphite alkene film radius, and the internal diameter is 0.6mm, is made by PVC resin, and this structure not only can play the insulating effect of support, can also avoid the hindrance to the magnetic circuit, is solenoid and plays the biggest effect.

5. The integrated graphene acoustic sensor according to claim 1, wherein: the electromagnetic coil is composed of multiple turns of enameled wires with the same wire diameter, the whole electromagnetic coil is of an annular structure, the outer diameter of the annular structure is 1mm, the inner diameter of the annular structure is 0.4mm, the thickness of the annular structure is 100 micrometers, and after current is introduced into the annular electromagnetic coil, a strong magnetic field can be generated inside the coil, so that the signal output of the sensor is improved.

6. The integrated graphene acoustic sensor according to claim 1, wherein: the outer diameter of the supporting plate of the lower polar plate is 1mm, the thickness of the copper substrate is 50 micrometers, and the thickness of the supporting plate is 100 micrometers.