Ultrasonic intensity measuring device

Abstract

The invention relates to the technical field of ultrasonic measurement, in particular to an ultrasonic intensity measurement device which comprises a first measurement layer, a second measurement layer, a metal transition layer, an electrode plate, an electric signal measurement module and an electric signal analysis module. The first measurement layer and the second measurement layer are arranged in an attached manner, and a semiconductor heterojunction can be formed between the first measurement layer and the second measurement layer; the two metal transition layers are arranged on the opposite sides of the first measurement layer and the second measurement layer respectively, and the metal transition layers are in ohmic contact with the first measurement layer or the second measurement layer; the negative electrode side of the electrode plate is attached to the metal transition layer close to the first measuring layer; the two electrode plates are respectively arranged on the opposite sides of the metal transition layer; the two electrode plates are electrically connected with the electric signal measuring module; the electric signal measurement module is in communication connection with the electric signal analysis module; and weak ultrasonic signal intensity measurement is realized.

Description

Technical Field

[0001] The invention relates to the technical field of ultrasonic measurement, in particular to an ultrasonic intensity measuring device. Background Art

[0002] Ultrasound is widely used in many technologies, such as echolocation technology, ultrasonic imaging technology, etc. Many organisms also use ultrasound to transmit signals; how to measure the ultrasonic intensity in the environment is one of the core issues in ultrasonic technology; currently, the measurement of environmental ultrasonic intensity is mainly achieved by using the piezoelectric effect, such as a high-intensity focused ultrasonic measurement sensor with application number CN201920101579.9, which includes a sensor housing, a probe, a PVDF piezoelectric film and a wire; its main working principle is to use the mechanical effect of ultrasound on piezoelectric ceramics to drive the piezoelectric ceramics to deform and generate electrical signals, and judge the ultrasonic intensity according to the strength of the electrical signals; in actual applications, it can be found that since the electrical signals generated by piezoelectric ceramics under ultrasound are very weak, it is difficult to detect some low-intensity ultrasonic signals, such as less than 10mW / m using the piezoelectric effect. 2 Therefore, measuring the intensity of weak ultrasonic signals is a major difficulty in ultrasonic measurement technology. Summary of the invention

[0003] In view of the deficiencies in the prior art, an object of the present invention is to provide an ultrasonic intensity measuring device capable of measuring the intensity of weak ultrasonic signals.

[0004] The technical solution adopted by the present invention to solve its technical problem is:

[0005] An ultrasonic intensity measuring device comprises a first measuring layer, a second measuring layer, a metal transition layer, an electrode sheet, an electric signal measuring module and an electric signal analyzing module; the first measuring layer and the second measuring layer are arranged in close contact, a semiconductor heterojunction can be formed between the first measuring layer and the second measuring layer, and under the action of ultrasound, the first measuring layer is the side that loses electrons, and the second measuring layer is the side that gains electrons; two metal transition layers are provided, which are respectively arranged on the opposite sides of the first measuring layer and the second measuring layer, and form ohmic contact with the first measuring layer or the second measuring layer; the negative side of the electrode sheet is arranged in close contact with the metal transition layer close to the first measuring layer; two electrode sheets are provided, which are respectively arranged on the opposite sides of the metal transition layer; the two electrode sheets are electrically connected to the electric signal measuring module, the electrode sheet close to the second measuring layer is electrically connected to the positive pin of the electric signal measuring module, and the electrode sheet close to the first measuring layer is electrically connected to the negative pin of the electric signal measuring module; the electric signal measuring module is communicatively connected to the electric signal analyzing module, and the measured electric signal is transmitted to the electric signal analyzing module for analysis.

[0006] Preferably, a further technical solution of the present invention is:

[0007] Preferably, the electrical signal measuring module is a voltage measuring module or a current measuring module.

[0008] Preferably, when a PN junction is formed between the first measurement layer and the second measurement layer, the first measurement layer is a P-type semiconductor layer, and the second measurement layer is an N-type semiconductor layer.

[0009] Compared with the prior art, the present invention adopting the above technical solution has the following outstanding features:

[0010] A semiconductor heterojunction is formed at the contact interface between the first measuring layer and the second measuring layer. Ultrasonic waves carry mechanical vibration energy and act on the semiconductor heterojunction to excite electron-hole pairs at the semiconductor heterojunction interface. The electron-hole pairs are separated under the action of the interface electric field to generate a direct current signal. The electric signal is measured by an electric signal measurement module, and the intensity of the electric signal is analyzed by an electric signal analysis module to obtain the environmental ultrasonic intensity. Under the same ultrasonic intensity, the electric signal generated by the semiconductor heterojunction is stronger than the electric signal generated by the piezoelectric ceramic. Therefore, the device realizes the measurement of low-intensity ultrasonic signals. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 is a schematic structural diagram of an ultrasonic intensity measuring device according to an embodiment of the present invention;

[0012] Figure 2 Schematic diagram of the working principle of the ultrasonic intensity measuring device in an embodiment of the present invention;

[0013] Figure 3 It is a curve diagram of actual measured voltage values ​​at different ultrasonic intensities in Experiment 1 of the present invention;

[0014] Figure 4 is a curve diagram of actual measured voltage values ​​at different ultrasonic intensities in Experiment 2 of the present invention;

[0015] Figure 5 It is the actual measured value of the output voltage in ultrasound of a specified intensity in Experiment 3 of the present invention.

[0016] Explanation of the accompanying drawings: 1. First measurement layer; 2. Second measurement layer; 3. Metal transition layer; 4. Electrode sheet; 5. Electrical signal measurement module; 6. Electrical signal analysis module. DETAILED DESCRIPTION

[0017] The present invention is further described below in conjunction with specific embodiments, the purpose of which is only to provide a better understanding of the content of the present invention. Therefore, the examples given do not limit the protection scope of the present invention.

[0018] like Figure 1As shown, this embodiment provides an ultrasonic intensity measuring device, including a first measuring layer 1, a second measuring layer 2, a metal transition layer 3, an electrode sheet 4, an electrical signal measuring module 5 and an electrical signal analyzing module 6; the first measuring layer 1 and the second measuring layer 2 are arranged in a close relationship, and a semiconductor heterojunction can be formed between the first measuring layer 1 and the second measuring layer 2. Under the action of ultrasound, the first measuring layer 1 is the side that loses electrons, and the second measuring layer 2 is the side that gains electrons; two metal transition layers 3 are provided, which are respectively arranged on the opposite sides of the first measuring layer 1 and the second measuring layer 2, and form ohmic contact with the first measuring layer 1 or the second measuring layer 2; the electrode sheet The negative side of 4 is arranged in contact with the metal transition layer 3 close to the first measuring layer 1; two electrode sheets 4 are arranged, which are respectively arranged on the opposite sides of the metal transition layer 3; the two electrode sheets 4 are electrically connected to the electric signal measurement module 5, the electrode sheet 4 close to the second measuring layer 2 is electrically connected to the positive pin of the electric signal measurement module 5, and the electrode sheet 4 close to the first measuring layer 1 is electrically connected to the negative pin of the electric signal measurement module 5; the electric signal measurement module 5 is communicatively connected with the electric signal analysis module 6, and the measured electric signal is transmitted to the electric signal analysis module 6 for analysis; wherein the electric signal measurement module 5 is a voltage measurement module or a current measurement module.

[0019] like Figure 2 As shown, it is the working principle diagram of the device (also known as the sonovoltaic effect principle diagram). Taking the semiconductor heterogeneity as a PN junction as an example, when a PN junction is formed between the first measuring layer 1 and the second measuring layer 2, the first measuring layer 1 can use a P-type semiconductor layer, and the second measuring layer 2 can use an N-type semiconductor layer; a PN junction is formed on the contact side of the P-type semiconductor layer and the N-type semiconductor layer, and an ohmic contact is formed with the metal transition layer 3 and the P-type semiconductor layer or the N-type semiconductor layer. When the ultrasonic wave in the environment reaches the PN junction, the PN junction absorbs the ultrasonic energy and generates electron-hole pairs in the junction area; the electron-hole pairs are separated under the action of the interface electric field to generate voltage and current signals. The greater the ultrasonic intensity that excites the sonovoltaic effect, the stronger the electrical signal. There is a definite relationship between the electrical signal and the ultrasonic intensity. The measurement of the environmental ultrasonic energy intensity can be achieved by measuring the electrical signal output by the sonovoltaic device.

[0020] Furthermore, the PN junction can be replaced with any semiconductor heterojunction (such as the Schottky junction at the metal semiconductor interface) to achieve the conversion of ultrasound into electrical signals and the measurement of ultrasound intensity; in this application, when the semiconductor heterojunction is a Schottky junction, the following experiment was conducted.

[0021] Experiment 1: The size of the first measurement layer 1 and the second measurement layer 2 is 5mm*5mm*1mm, the first measurement layer 1 uses a 100Ωcm P-type silicon wafer, the second measurement layer 2 uses a copper sheet, and the metal transition layer 3 uses an aluminum foil with a thickness of 0.5mm; Figure 3, is a graph of the actual measured voltage under different ultrasonic intensities; the ultrasound is generated by a 40kHz ultrasonic generator, and the ultrasonic intensity is controlled at 1mW / m 2 To 10mW / m 2 Experiments have found that when the ultrasound intensity is as low as 10mW / m 2 When the device is turned on, the output voltage is as high as about 5V, and the output voltage is basically linearly related to the ultrasonic intensity. The specific relationship is as follows:

[0022] V≈0.5×P

[0023] Where V is the device output voltage (in V), P is the ultrasonic intensity (in mW / m 2 ).

[0024] Experiment 2: The size of the first measurement layer 1 and the second measurement layer 2 is 5mm*5mm*1mm. The first measurement layer 1 uses a 100Ωcm copper sheet, the second measurement layer 2 uses a 100Ωcm N-type silicon sheet, and the metal transition layer 3 uses a titanium foil with a thickness of 0.5mm. Figure 4 , which is the actual measured voltage curve under different ultrasonic intensities in Experiment 2; the ultrasound is generated by a 40kHz ultrasonic generator, and the ultrasonic intensity is controlled at 11mW / m 2 Up to 20mW / m 2 The experiment found that when the ultrasound intensity is 20mW / m 2 When the device is turned on, the output voltage is as high as about 5V, and the output voltage is basically linearly related to the ultrasonic intensity. The specific relationship is as follows:

[0025] V≈0.4×P

[0026] Where V is the device output voltage (in V), P is the ultrasonic intensity (in mW / m 2 ).

[0027] To facilitate the movement of the device, the first measurement layer 1, the second measurement layer 2, the metal transition layer 3, the electrode sheet 4, and the end of the wire electrically connected to the electrode sheet 4 can be packaged as a whole using heat shrinkable plastic.

[0028] Experiment 3: We connected a piezoelectric ceramic to a preamplifier that can amplify the signal 10 times (if the preamplifier is not connected, no effective voltage can be measured) and placed it in a 10mW / m 2 Intensity of ultrasound, such as Figure 5 As shown, the maximum output voltage is only 0.1V; this means that the piezoelectric ceramic is 2 The original output voltage of the strong ultrasound is only 0.01V, which is much smaller than the output voltage (about 5V) based on the "acoustic volt effect" in this patent.

[0029] The present invention utilizes ultrasound to carry mechanical vibration energy to excite electron-hole pairs at the semiconductor heterojunction interface, causing it to generate a direct current signal, thereby realizing the measurement of environmental ultrasonic intensity. Moreover, by comparing experiments one, two, and three, it can be seen that since the internal impedance of piezoelectric ceramics is very high, the output signal is very weak. The device has lower internal impedance than piezoelectric ceramics and outputs a stronger electrical signal, thereby realizing the measurement of low-intensity ultrasonic signals.

[0030] The above description is only the preferred embodiment of the present invention, and does not limit the scope of rights of the present invention. All equivalent changes made by using the contents of the present invention specification and its drawings are included in the scope of rights of the present invention.

Claims

1. An ultrasonic intensity measuring device, characterized in that: It comprises a first measuring layer (1), a second measuring layer (2), a metal transition layer (3), an electrode sheet (4), an electric signal measuring module (5) and an electric signal analyzing module (6); The first measurement layer (1) and the second measurement layer (2) are arranged in close contact with each other, and a semiconductor heterojunction can be formed between the first measurement layer (1) and the second measurement layer (2). Under the action of ultrasound, the first measurement layer (1) is a side that loses electrons, and the second measurement layer (2) is a side that gains electrons. Two metal transition layers (3) are provided, which are respectively provided on the opposite sides of the first measurement layer (1) and the second measurement layer (2), and form ohmic contact with the first measurement layer (1) or the second measurement layer (2); The negative electrode side of the electrode sheet (4) is arranged in contact with the metal transition layer (3) close to the first measurement layer (1); Two electrode sheets (4) are provided, and are respectively provided on opposite sides of the metal transition layer (3); the two electrode sheets (4) are electrically connected to the electric signal measurement module (5); the electrode sheet (4) close to the second measurement layer (2) is electrically connected to the positive electrode pin of the electric signal measurement module (5), and the electrode sheet (4) close to the first measurement layer (1) is electrically connected to the negative electrode pin of the electric signal measurement module (5); the electric signal measurement module (5) is communicatively connected to the electric signal analysis module (6), and the measured electric signal is transmitted to the electric signal analysis module (6) for analysis.

2. The ultrasonic intensity measuring device according to claim 1, characterized in that: The electrical signal measuring module (5) is a voltage measuring module or a current measuring module.

3. The ultrasonic intensity measuring device according to claim 1, characterized in that: When a PN junction is formed between the first measurement layer (1) and the second measurement layer (2), the first measurement layer (1) is a P-type semiconductor layer, and the second measurement layer (2) is an N-type semiconductor layer.

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