Ultrasonic energy collection structure and method for micro-robot

Abstract

The invention relates to the technical field of wireless charging, in particular to an ultrasonic rechargeable battery for a micro-robot, which is characterized in that insulating layers are deposited on two opposite sides of a substrate, a P-type semiconductor layer is deposited on the outer side of the insulating layer on one side, and an N-type semiconductor layer is deposited on the outer side of the insulating layer on the other side; the problem that an existing ultrasonic energy converter for the micro-robot is insufficient in conversion energy efficiency is solved, and the wireless energy supply problem of the micro-robot in a human body or other closed areas where illumination cannot reach is solved.

Description

Technical Field

[0001] The present invention relates to the field of wireless charging technology, in particular to an ultrasonic energy collection structure and method for a micro robot. Background Art

[0002] Microrobots have broad application prospects in various fields. The backwardness of wireless power supply technology for microrobots is one of the core issues hindering the development of microrobots. Compared with light power supply, ultrasonic wireless power supply has strong penetration and can directly act on the human body. It is the preferred power supply method for microrobots in medical and other fields. Currently, ultrasonic energy converters are commonly used to convert ultrasonic energy into electrical energy. Ultrasonic energy converters are made of piezoelectric materials and use the mechanical force of ultrasound and the positive piezoelectric effect of the material to convert ultrasonic energy into electrical energy.

[0003] In the prior art, ultrasonic energy converters based on piezoelectric materials are not convenient for use in micro-robots, and there are the following problems: 1. The volume of the micro-robot is increased, which is not conducive to practical application; 2. The piezoelectric effect is a body effect. When the volume of the ultrasonic energy converter decreases with the size of the robot, the energy conversion performance of the device is severely attenuated, especially when the size of the robot is as small as sub-millimeter scale. The performance of the ultrasonic energy converter based on the piezoelectric effect is not enough to support the micro-robot's demand for electrical energy. Summary of the invention

[0004] In view of the deficiencies in the prior art, the purpose of the present invention is to provide a method that can solve the problem of insufficient conversion efficiency of a miniature ultrasonic energy converter, and to provide an ultrasonic energy collection structure and method for a miniature robot for use inside the human body or other closed areas where light cannot reach.

[0005] The technical solution adopted by the present invention to solve its technical problem is:

[0006] An ultrasonic rechargeable battery for a micro robot has insulating layers deposited on two opposite sides of a substrate, a P-type semiconductor layer deposited on the outer side of the insulating layer on one side, and an N-type semiconductor layer deposited on the outer side of the insulating layer on the other side.

[0007] Preferably, a further technical solution of the present invention is:

[0008] Preferably, the thickness of the P-type semiconductor layer is greater than 10 nm and less than 150 nm, the thickness of the N-type semiconductor layer is greater than 10 nm and less than 150 nm, and the thickness of the insulating layer is greater than 10 nm and less than 1000 nm.

[0009] Preferably, the resistivity of the P-type semiconductor layer and the N-type semiconductor layer is 0.0015Ωcm-1Ωcm.

[0010] The present invention also discloses an ultrasonic battery charging method for a micro robot, which is performed using an ultrasonic charging battery for the micro robot, and the specific steps are as follows:

[0011] S1: depositing insulating layers on two opposite surfaces of the substrate, and depositing a P-type semiconductor layer and an N-type semiconductor layer on the two insulating layers respectively;

[0012] S2: placing a battery having a P-type semiconductor layer, an N-type semiconductor layer and an insulating layer in a liquid;

[0013] S3: Under ultrasonic energy, electron-hole pairs are generated at the interface between the P-type semiconductor layer and the liquid, and at the interface between the N-type semiconductor layer and the liquid. The electrons and holes move under the action of the built-in electric field, causing the potential of the P-type semiconductor layer to be higher than that of the N-type semiconductor layer, forming an electric potential difference that becomes a power source to charge the microrobot.

[0014] Compared with the prior art, the present invention adopting the above technical solution has the following outstanding features:

[0015] The invention solves the problem of insufficient energy conversion efficiency of existing ultrasonic energy converters for micro robots and solves the problem of wireless energy supply for micro robots inside the human body or other closed areas where light cannot reach. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is a schematic diagram of the structure of an ultrasonic rechargeable battery in an embodiment of the present invention;

[0017] Figure 2 is a schematic structural diagram of another ultrasonic rechargeable battery in an embodiment of the present invention;

[0018] Figure 3 is a diagram of the energy band structure of the N-type semiconductor layer in an embodiment of the present invention;

[0019] Figure 4 is a diagram of the energy band structure of the P-type semiconductor layer in an embodiment of the present invention;

[0020] Figure 5 This is a schematic diagram comparing the effects of different liquids on the voltage of the ultrasonic charging battery in the embodiment of the present invention:

[0021] Figure 6 1 is a schematic diagram comparing the effects of different liquids on the current of an ultrasonic charging battery in an embodiment of the present invention;

[0022] Figure 7 1 is a schematic diagram comparing the effect of the resistivity of the P-type semiconductor layer on the current of the ultrasonic charging battery in the embodiment of the present invention;

[0023] Figure 8It is a comparative schematic diagram of the effect of the resistivity of the N-type semiconductor layer on the current of the ultrasonic charging battery in the embodiment of the present invention.

[0024] Explanation of the reference numerals: 1. substrate; 2. insulating layer; 3. N-type semiconductor layer; 4. P-type semiconductor layer. DETAILED DESCRIPTION

[0025] 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.

[0026] like Figures 1 to 4 As shown, this embodiment provides an ultrasonic rechargeable battery for a micro robot, wherein an insulating layer 2 is deposited on two opposite sides of a substrate 1, a P-type semiconductor layer 4 is deposited on the outer side of the insulating layer 2 on one side, and an N-type semiconductor layer 3 is deposited on the outer side of the insulating layer 2 on the other side; wherein the insulating layer 2 is used to insulate the P-type semiconductor layer 4, the N-type semiconductor layer 3 from the substrate 1 to avoid short circuit, and the insulating layer 2 can be made of materials that are easy to coat, such as silicon nitride, silicon oxide, aluminum oxide, polytetrafluoroethylene, and silicon carbide; the P-type semiconductor layer 4, the N-type semiconductor layer 3, and the insulating layer 2 can be coated by magnetron sputtering, atomic layer deposition, laser-assisted deposition, and the like.

[0027] Furthermore, the thickness of the P-type semiconductor layer 4 is greater than 10 nm and less than 150 nm, the thickness of the N-type semiconductor layer 3 is greater than 10 nm and less than 150 nm, and the thickness of the insulating layer 2 is greater than 10 nm and less than 1000 nm.

[0028] Furthermore, the resistivity of the P-type semiconductor layer 4 and the N-type semiconductor layer 3 is 0.0015Ωcm-1Ωcm.

[0029] An ultrasonic battery charging method for a micro robot is implemented by using an ultrasonic rechargeable battery for the micro robot, and the specific steps are as follows:

[0030] S1: depositing insulating layers 2 on two opposite surfaces of a substrate 1 , and depositing a P-type semiconductor layer 4 and an N-type semiconductor layer 3 on the two insulating layers 2 , respectively.

[0031] S2: placing the battery with the P-type semiconductor layer 4, the N-type semiconductor layer 3 and the insulating layer 2 in a liquid; wherein the liquid may be an aqueous solution, deionized water, ultrapure water, NaCl solutions of various concentrations, etc.

[0032] S3: Under ultrasonic energy, the liquid vibrates, causing the atoms at the interface of the liquid and the semiconductor to collide, resulting in the breaking and generation of chemical bonds. The generation of chemical bonds releases energy and stimulates the generation of electron-hole pairs at the interface. Since the majority carriers of P-type semiconductors are holes and the majority carriers of N-type semiconductors are electrons, the built-in electric fields formed at the contact interface between the two and the liquid due to carrier diffusion are in opposite directions, and their energy band structures are also different (such as Figure 2 , 3 ), under the stimulation of ultrasonic waves, electron-hole pairs are generated at the contact interface between the P-type semiconductor layer 4 and the liquid, and at the contact interface between the N-type semiconductor layer 3 and the liquid. The electrons and holes move under the action of the built-in electric field, causing the potential on one side of the P-type semiconductor layer 4 to be higher than that of the liquid, while the potential on the side of the N-type semiconductor layer 3 is lower than that of the liquid. That is, the potential of the P-type semiconductor is higher than that of the N-type semiconductor, forming a potential difference, which becomes a power source, and then charges the micro robot.

[0033] To verify the effect of different liquids on the energy efficiency of ultrasonic rechargeable batteries, such as Figure 5 , 6 , Experiment 1 is set for verification. In Experiment 1, the resistivity of the P-type semiconductor layer 4 is 0.1Ωcm, the resistivity of the N-type semiconductor layer 3 is 1Ωcm, and ultrapure water, 3g / l NaCl solution, 6g / l NaCl solution, and 9g / l NaCl solution are used as liquids respectively; Figure 5 is a schematic diagram of voltage change. Figure 6 is a schematic diagram of current change, 5-(a) is a time / voltage change diagram of an ultrasonic charging battery using ultrapure water as a solution, Figure 5 -(a) and 6-(a) show that, when ultrapure water is used as the solution, the P-type semiconductor layer 4 has a resistivity of 0.1Ωcm, the N-type semiconductor layer 3 has a resistivity of 1Ωcm, the average discharge voltage is 2.2V, and the average current is 2uA; Figure 5 -(b) and 6-(b) show that, using 3g / lNaCl solution as the liquid, the P-type semiconductor layer 4 with a resistivity of 0.1Ωcm, the N-type semiconductor layer 3 with a resistivity of 1Ωcm, the average discharge voltage is 2.5V, and the average current is 6uA; Figure 5 -(c) and 6-(c) show that, using 6g / l NaCl solution as the liquid, the P-type semiconductor layer 4 with a resistivity of 0.1Ωcm, the N-type semiconductor layer 3 with a resistivity of 1Ωcm, the average discharge voltage is 2.2V, and the average current is 6uA; Figure 5 -(d) and 6-(d) show that when 9g / l NaCl solution is used as the liquid, the P-type semiconductor layer 4 has a resistivity of 0.1Ωcm, the N-type semiconductor layer 3 has a resistivity of 1Ωcm, the average discharge voltage is 2.5V, and the average current is 6uA.

[0034] In order to verify the influence of different resistivity on the energy efficiency of ultrasonic rechargeable batteries, Experiment 2 and Experiment 3 were set up; Figure 7 In experiment 2, 9g / l NaCl solution is used as the liquid, and the resistivity of the N-type semiconductor layer 3 is 1Ωcm. The effect of the P-type semiconductor layer 4 with different resistivities on the energy efficiency of the ultrasonic rechargeable battery is verified. 7-(a) The P-type semiconductor layer 4 with a resistivity of 1Ωcm is used, and the average discharge voltage is 1V; 7-(b) The P-type semiconductor layer 4 with a resistivity of 0.1Ωcm is used, and the average discharge voltage is 2.5V; 7-(c) The P-type semiconductor layer 4 with a resistivity of 0.01Ωcm is used, and the average discharge voltage is 0.5V; 7-(d) The P-type semiconductor layer 4 with a resistivity of 0.0015Ωcm is used, and the average discharge voltage is 0.15V; Figure 8 In experiment 3, 9g / l NaCl solution was used as the liquid, and the resistivity of the P-type semiconductor layer 4 was 1Ωcm. The effect of the N-type semiconductor layer 3 with different resistivities on the energy efficiency of the ultrasonic rechargeable battery was verified. 7-(a) The N-type semiconductor layer 3 with a resistivity of 1Ωcm was used, and the average discharge voltage was 1V; 7-(b) The N-type semiconductor layer 3 with a resistivity of 0.1Ωcm was used, and the average discharge voltage was 0.7V; 7-(c) The N-type semiconductor layer 3 with a resistivity of 0.01Ωcm was used, and the average discharge voltage was 0.1V; 7-(d) The N-type semiconductor layer 3 with a resistivity of 0.0015Ωcm was used, and the average discharge voltage was 0.25V.

[0035] Therefore, by adjusting the resistivity and the current and voltage of the ultrasonic charging battery, different micro-robots can be adapted, which solves the problem of insufficient energy conversion efficiency of existing ultrasonic energy converters for micro-robots and the problem of wireless power supply for micro-robots inside the human body or other closed areas where light cannot reach.

[0036] The attenuation equation of light in the human body can be expressed as:

[0037] I=I0e -α1*

[0038] I is the light intensity after attenuation, I0 is the initial light intensity, α1 is the attenuation coefficient, and x is the depth.

[0039] The attenuation equation of ultrasonic energy in the human body can be expressed as:

[0040] I=I0e -α2x

[0041] I is the sound intensity after attenuation, I0 is the initial sound intensity, α2 is the attenuation coefficient, and x is the depth.

[0042] Since the energy loss of sound is relatively small when it propagates in a medium, especially when it propagates in a solid, while light is affected by the absorption and scattering of the medium during propagation, resulting in a greater degree of attenuation of light energy in different media, the acoustic attenuation coefficient is usually smaller than the optical attenuation coefficient. Therefore, in the human body, the performance of photovoltaic devices is much lower than that of ultrasonic devices, so ultrasonic rechargeable batteries used in micro-robots are more suitable for the human body than laser wireless rechargeable batteries.

[0043] Compared with the ultrasonic energy converter, since the output power of the ultrasonic energy converter is related to the volume of the piezoelectric material, and the output power of the ultrasonic rechargeable battery used for the microrobot is related to the surface area of ​​the P-type semiconductor layer and the N-type semiconductor layer, as the volume of the microrobot decreases, the output power of the ultrasonic energy converter decreases to the cubic power, and the power of the present invention decreases to the quadratic power. Therefore, when the volume of the microrobot reaches the millimeter or micron level, the energy efficiency of the ultrasonic rechargeable battery used for the microrobot is better than that of the ultrasonic energy converter.

[0044] 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 rechargeable battery for microrobots, Features: An insulating layer is deposited on two opposite sides of the substrate, a P-type semiconductor layer is deposited on the outer side of the insulating layer on one side, and an N-type semiconductor layer is deposited on the outer side of the insulating layer on the other side.

2. The ultrasonic rechargeable battery for a micro robot according to claim 1, Features: The thickness of the P-type semiconductor layer is greater than 10 nm and less than 150 nm, the thickness of the N-type semiconductor layer is greater than 10 nm and less than 150 nm, and the thickness of the insulating layer is greater than 10 nm and less than 1000 nm.

3. The ultrasonic rechargeable battery for a micro robot according to claim 1, Features: The resistivity of the P-type semiconductor layer and the N-type semiconductor layer is 0.0015Ωcm-1Ωcm.

4. An ultrasonic battery charging method for microrobots, It is characterized in that The method is carried out by using the ultrasonic rechargeable battery for a micro robot as claimed in any one of claims 1 to 3, and the specific steps are as follows: S1: depositing insulating layers on two opposite surfaces of the substrate, and depositing a P-type semiconductor layer and an N-type semiconductor layer on the two insulating layers respectively; S2: placing a battery having a P-type semiconductor layer, an N-type semiconductor layer and an insulating layer in a liquid; S3: Under ultrasonic energy, electron-hole pairs are generated at the interface between the P-type semiconductor layer and the liquid, and at the interface between the N-type semiconductor layer and the liquid. The electrons and holes move under the action of the built-in electric field, causing the potential of the P-type semiconductor layer to be higher than that of the N-type semiconductor layer, forming an electric potential difference that becomes a power source to charge the microrobot.

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