Human body coupled triboelectric wireless power transfer technology

Abstract

This invention relates to a technology and its applications that converts wasted energy (kinetic and biomechanical energy) from the surroundings into electrical energy through energy harvesting technology, and utilizes the body as a power communication medium to transmit power to any necessary part, whether inside or outside the body. This invention presents a wireless power communication technology that eliminates the need for separate wire connections between the power generation device and the battery. By resolving the power line issues of conventional energy harvesting, this is expected to accelerate the commercialization of energy harvesting technology.

Description

Technology Field

[0001] The present invention relates to a technology that converts wasted energy (kinetic energy and biomechanical energy) in the surroundings into electrical energy through energy harvesting technology, utilizes the body as a power communication medium to transmit power to any necessary part inside or outside the body, and to the application thereof. Background Technology

[0003] To enhance the convenience of human life, various wearable devices (healthcare and entertainment) are being actively developed, and commercialized products such as earbuds and smartwatches are being released. In the case of wearable devices, development is focused on lightweighting and miniaturization to reduce discomfort when worn. Consequently, battery size is also decreasing, leading to capacity limitations.

[0004] Due to battery capacity limitations resulting from the lightweighting and miniaturization of wearable devices, operating times and charging cycles have become shorter, causing inconvenience to users. To overcome this, energy harvesting technology, which enables charging even while being worn and used, is being proposed as a new energy solution. However, charging based on energy harvesting technology requires a wired connection between the wearable device and the energy harvester, which restricts movement due to the connecting wires. To address this, wireless transmission technologies based on electromagnetic waves and radio frequencies have been proposed, but they have not been able to serve as a practical solution due to concerns regarding harm to the human body, low efficiency, and interference caused by the human body.

[0005] Meanwhile, to meet the social demand for disease-free longevity, the demand for implantable medical devices operating within the human body and treatments utilizing electrical energy is increasing explosively. Currently commercialized implantable medical devices generate electrical signals from power sources composed of batteries and circuits. Conventional battery-powered neurostimulators require replacement surgery when the battery is depleted, resulting in massive social costs. Furthermore, due to limitations in battery size, there is a problem in that it is difficult to reduce the device size beyond a certain limit or modify its shape.

[0006] To address the aforementioned problems, research is being conducted on battery-free implantable neurostimulators. However, commonly used wireless communication technologies such as RFID and NFC have short transmission distances and have not been proven harmless to the human body. Furthermore, electromagnetic waves cannot penetrate metal packaging materials and have a body shadowing effect, which limits their commercialization. While the power requirements of implantable devices are increasing to perform various functions such as real-time monitoring and treatment, the development of energy solutions for implantable devices is currently limited. Consequently, there is a growing need to develop an in-body energy solution for electrical stimulation that is harmless to the human body and can maximize treatment efficiency.

[0007] delete Prior art literature

[65535] Published Patent Application No. 10-2023-0124320 (Aug. 25, 2023) Registered Patent Application No. 10-2570253 (September 5, 2023) Published Patent Application No. 10-2022-0057184 (May 9, 2022) The problem to be solved

[0008] The present invention aims to provide a new, high-efficiency energy solution that is harmless to the human body by utilizing the human body as an energy transmission medium to continuously transmit electrical energy produced by energy harvesting to a desired location, thereby implementing various internal and external application technologies. means of solving the problem

[0010] A human body-based power transmission triboelectric generator according to one embodiment of the present invention includes a triboelectric generator attached to a human body through a first electrode; and a wearable device attached to a human body through a second electrode, wherein electrical energy is generated from the triboelectric generator by the movement of the human body, and the generated electrical energy is supplied to the wearable device through the human body, and the second electrode includes a receiving electrode.

[0011] The above electrical energy represents an alternating current frequency of 1 kHz or less.

[0012] A human body-based power transmission triboelectric generator according to an additional embodiment of the present invention comprises: a triboelectric generator attached to a human body through a first electrode; a second electrode inserted into a human body; and an implantable device inserted into a human body connected to the second electrode, wherein electrical energy is generated in the triboelectric generator by the movement of the human body, and the generated electrical energy is supplied to the implantable device through the human body, and the second electrode includes a receiving electrode.

[0013] The above electrical energy represents an alternating current frequency of 1 kHz or less.

[0014] The receiving electrode above is made of a biodegradable material.

[0015] delete

[0016] The above-mentioned implantable device includes a nerve stimulation part, and the nerve stimulation part includes an electrode part that wraps around or is wrapped around the nerve, and nerve stimulation is possible through such a nerve stimulation part. The above-mentioned implantable device includes an implantable medical device. The current generated by the triboelectric generator is transmitted to the human body base and can exit through a ground electrode.

[0017] delete

[0018] A human body-based power transmission triboelectric generator according to an additional embodiment of the present invention comprises: a triboelectric generator attached to a human body through a first electrode; and a charging unit attached to a human body through a second electrode, wherein the second electrode includes a receiving electrode, and the current generated by the triboelectric generator is transmitted to a human body and can be stored through a charging circuit of the charging unit.

[0019] The above electrical energy represents an alternating current frequency of 1 kHz or less. Effects of the invention

[0021] This invention presents a wireless power communication technology that eliminates the need for a separate wire connection between the power generator and the battery. By resolving the power line issues of existing energy harvesting, it is expected that this will accelerate the commercialization of energy harvesting technology.

[0022] In this invention, the human body serves as the substitute for the connection between the power generation device and the wearable device. Since this technology enables the same power communication across any body part, not just specific ones, it can be applied to various wearable devices. Consequently, it is expected that the increasing energy requirements can be met by improving the battery operating time of wearable devices and sensors, which are in increasing demand in daily life. It can be applied to all energy harvesting technologies that generate alternating current, and this is expected to lead to the commercialization of various energy harvesting technologies. Furthermore, triboelectric energy (triboelectric current) generated from the triboelectric power generation device can be transmitted through the human body and can exit through the ground as shown in Fig. 1.

[0023] Furthermore, this invention presents a wireless power communication technology through the human body that eliminates the need for a separate wire connection between the power generation device and the electrode inserted into the body. In particular, it can overcome the limitations of electrical stimulation therapy and the battery replacement issues associated with implantable medical devices caused by the limitations of RF energy transmission methods. By resolving the power line issues of existing energy harvesting, it is expected that the commercialization of energy harvesting technology can be accelerated. In this invention, the human body serves as a substitute for the connection between the power generation device and the electrode inserted into the body, thereby eliminating patient discomfort and the risk of disconnection caused by wires between the device and the implantable device. Additionally, it can resolve the battery replacement issue, which is identified as a limitation of existing implantable medical devices, thereby minimizing the risk to the patient. Since the electrode inserted into the body can be manufactured with a limited lifespan, this invention offers the advantage of eliminating the need for re-surgery to remove the device and electrode, which has caused social and economic burdens for patients in implantable medical devices. Brief explanation of the drawing

[0025] FIGS. 1 and 2 illustrate schematic diagrams of a human body-based power transmission triboelectric generator according to one embodiment of the present invention. Figure 3 illustrates a graph of human body wireless power communication outside the body through a function generator. FIG. 4 illustrates a graph of wireless power communication voltage and current within the human body using a human body-based power transmission triboelectric generator according to one embodiment of the present invention. FIG. 5 illustrates a graph of voltage and current for external wireless power communication using a human body-based power transmission triboelectric generator according to one embodiment of the present invention. Figure 6 illustrates a graph of human body wireless power transmission efficiency according to body parts outside the body. Figure 7 shows the type of grounding electrode when connecting with a device via human body wireless power communication outside the body. Figure 8 shows a graph of transmission efficiency according to electrode insertion depth in an ex-vivo experiment according to electrode depth in the body. Figure 9 illustrates capacitor charging through human body wireless power communication inside the body. Figure 10 is a stability test diagram of human body wireless power communication. Figure 11 is a diagram confirming nerve regeneration based on human body wireless power communication. FIG. 12 is a diagram illustrating the mechanism of wireless power transmission within the body through energy harvesting according to the present invention. Various embodiments are now described with reference to the drawings, and throughout the drawings, similar reference numerals are used to denote similar elements. For illustrative purposes, various descriptions are provided in this specification to facilitate an understanding of the invention. However, it is evident that these embodiments can be practiced without such specific descriptions. In other examples, known structures and devices are presented in the form of block diagrams to facilitate the description of the embodiments. Specific details for implementing the invention

[0026] Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings. As the present invention is susceptible to various modifications and may take various forms, specific embodiments are illustrated in the drawings and described in detail in the text. However, this is not intended to limit the present invention to the specific disclosed forms, and it should be understood that the invention includes all modifications, equivalents, and substitutions that fall within the spirit and scope of the invention. Similar reference numerals have been used for similar components in the description of each drawing.

[0027] The terms used in this application are used merely to describe specific embodiments and are not intended to limit the invention. The singular expression includes the plural expression unless the context clearly indicates otherwise. In this application, terms such as "comprising" or "having" are intended to indicate the presence of the features, steps, actions, components, parts, or combinations thereof described in the specification, and should be understood as not precluding the existence or addition of one or more other features, steps, actions, components, parts, or combinations thereof.

[0028] The energy harvesting technology for wireless power communication within the human body proposed in this invention utilizes the human body as a conductor to enable power communication of energy generated outside the body to a desired location within the body. In the case of triboelectric energy harvesting, a triboelectric charge is generated when different types of materials rub against each other. The generated triboelectric charge is compensated by changes in the distance between the frictional materials, and an electric current is generated as the charge moves through an external conductor. While a triboelectric generator can be driven through various movements of the human body, a triboelectric generator capable of utilizing the force generated on the soles of the feet when walking is used to generate high mechanical energy. In this invention, triboelectric energy (triboelectric current) generated through the human body can be transmitted, and this triboelectric current can be concentrated at a receiving electrode and then discharged through the Earth ground.

[0029] The part that converts energy sources generated by human movement into electrical energy can be named the energy generation unit, and the electrical energy converted through this can be transmitted to various places inside and outside the body using the human body as a conductor. The electrical energy transmitted into the body can exit the body again through grounding with the earth ground. The electrical energy transmitted via wireless power communication can also be stored in an energy storage device, such as a battery, at the energy usage unit.

[0030] The present invention is classified into in-body application technology and in-body application technology. Specifically, in the case of in-body application technology, it includes a high-power AC energy harvesting device, an electrode that can be attached to the human body, a human body-based wireless power communication, and a power management integrated circuit (PMIC) that converts AC current into DC current and converts it into a suitable amount of energy for electronic devices.

[0031] Below, I will first explain in vitro application technologies, and then sequentially explain in vivo application technologies. In this case, I will omit repeated explanations of overlapping parts.

[0032] A human body-based power transmission triboelectric generator corresponding to an in vitro application technology according to one embodiment of the present invention includes a triboelectric generator attached to the human body through a first electrode; and a wearable device attached to the human body through a second electrode.

[0033] As shown in FIGS. 1 and 2, the triboelectric generator can be directly attached to the human body through the first electrode, and the wearable device can be directly attached to the human body through the second electrode.

[0034] Triboelectric generators can be utilized in various forms, such as push-type, rotating-type, or sliding-type triboelectric generators. The triboelectric generator is attached to the human body via electrodes. For human safety and driving efficiency, electrodes of various types, such as metal or conductive hydrogel, can be directly attached to the human body. In this case, the electrodes may be attached directly to the human body, but they may also be attached indirectly, or connected to other electrodes attached to the human body via short wires.

[0035] Wearable devices are devices that operate by utilizing output generated from human-based triboelectric generators, and various types of devices can be utilized. These wearable devices are also attached directly to the human body via electrodes, and for human safety and operating efficiency, they can be directly attached to the human body using various types of electrodes, such as metal or conductive hydrogel.

[0036] Electrical energy is generated in a triboelectric generator by the movement of the human body, and the generated electrical energy is transmitted through the human body and supplied to the wearable device. In this case, although not illustrated, it may include an additional rectifier and an energy storage unit, and the generated energy may pass through the rectifier and then be stored in the energy storage unit and used by the wearable device when needed. The energy storage unit refers to a charging unit, and such a charging unit may be composed of a charging circuit.

[0037] Meanwhile, it is preferable that the triboelectric power generation element of the present invention be attached to the sole of the foot. This is because, when there is movement of the human body, the sole of the foot is the place where the greatest mechanical displacement and force are concentrated, so a large output can be generated from the triboelectric power generation element. However, it is not necessarily limited to the sole of the foot and can be attached to any location on the human body. In addition, multiple triboelectric power generation elements may be installed, and there may also be multiple wearable devices.

[0038] The second electrode includes a receiving electrode. A separate grounding electrode may exist, but it is generally not necessary as it is grounded to the earth ground. Therefore, the frictional current is transmitted through the human body, concentrated at the receiving electrode (the second electrode), utilized, and can exit through the ground.

[0039] The electrical energy generated by the movement of the human body in the triboelectric generator exhibits an alternating current frequency of several Hz, which is 1 kHz or less, or preferably 10 Hz or less, as a low frequency.

[0040] delete

[0041] Figure 3 utilized a function generator to verify whether the human body could be used as a single conductor. After generating and measuring energy in a specific frequency band using the function generator, the energy was wirelessly transmitted through the human body and measured to confirm that power transmission was possible. At this time, bio-attachable electrodes were attached to both sides of the human body; one side was designated as the 'transmitting electrode' that sends energy received from the 'energy generating unit' to the human body, and the other side as the 'receiving electrode' that moves the received energy to the 'energy using unit,' thereby verifying usability.

[0042] Through Figure 5, it was confirmed that the voltage and current values ​​of triboelectric energy harvesting in ex vivo applications and the voltage and current values ​​after human body power communication are transmitted with an efficiency of over 90%. This confirms that the human body has conductivity due to its water content, including body fluids and blood, and can operate as an RC circuit, allowing AC energy to pass through; it was analyzed that the human body is almost similar and therefore has high efficiency.

[0043] In addition, as shown in Figure 6, the effect of wireless power communication on distance was verified. After attaching the transmitting electrode to the left hand, the energy power communication efficiency was compared when the receiving electrode was positioned at the arm, neck, head, ankle, and right hand. Regardless of the distance of power communication, the energy communication efficiency exceeded 90% in all cases, and the validity of the data was verified by repeating the measurement at least three times.

[0044] In addition, when a grounding electrode is used, as shown in Fig. 7, it was confirmed that the charging efficiency of an energy storage unit, such as a battery, increases when the grounding electrode is used in the energy consumption unit. The electrodes proposed in this invention are broadly classified into three types: an earth ground electrode that performs direct grounding, and a semi-ground electrode designed to perform the role of grounding. For the semi-ground electrode, an insulating material is externally coated onto a metal electrode to restrict the movement of charge only through a wire, and the insulating material is fabricated using a liquid material through a deposition process. For the air ground electrode, the electrode is fabricated to receive compensation from electrons in the air, and it is designed to enable grounding through a discharge effect. While the grounding electrode offers the highest efficiency as it performs direct grounding, it causes inconvenience in use because grounding is performed through an additional external wire. Therefore, this invention proposes an air ground electrode and a semi-ground electrode in addition to the grounding electrode to maintain charging efficiency in the energy generation unit. While air grounding electrodes can solve the problem of external wiring, they have the disadvantage of low efficiency. Additionally, the proposed semi-grounding electrode can compensate for the low efficiency of air grounding electrodes by using an insulating material to replace air. In this case, the thickness of the insulating material can be from a few μm to tens of μm. Such grounding electrodes can be omitted.

[0045] So far, I have explained the in vitro application technology, and below, I will explain the in vivo application technology.

[0046] A human body-based power transmission triboelectric generator corresponding to an in-body application technology according to one embodiment of the present invention includes: a triboelectric generator attached to the human body through a first electrode; a second electrode inserted into the human body; and an implantable device inserted into the human body connected to the second electrode. In this case, the second electrode may be directly connected to an organ inside the human body instead of the implantable device inserted into the human body.

[0047] The triboelectric generator is directly attached to the human body through the first electrode.

[0048] The implantable device is inserted into the human body by connecting it to a second electrode inserted into the human body. The second electrode includes a receiving electrode.

[0049] In this case, the receiving electrode can be made of a biodegradable material.

[0050] Electrical energy is generated in a triboelectric generator by the movement of the human body, and the generated electrical energy can be supplied to an implantable device through the human body. In this case, the electrical energy exhibits an alternating current frequency of several Hz, which is 1 kHz or less, preferably 10 Hz or less, as a low frequency.

[0051] As shown in Fig. 12, wireless power transmission within the body is possible through energy harvesting. Currents exhibiting low alternating current frequencies, such as 10 Hz or lower, possess long wavelengths, allowing for efficient transmission anywhere within the body. Energy with such frequencies of several Hz has good penetration into the human body, enabling transmission over longer distances, a fact confirmed through experiments involving pork and rats. Meanwhile, as shown in the bottom right diagram of Fig. 12, capacitive coupling occurs outside the body. In this case, electro-quasistatic capacitive coupling is a wireless transmission technology that utilizes low-frequency electric fields, and the ground is typically a floating or earth. Additionally, high frequencies above 1 kHz are not suitable for internal transmission because they cannot penetrate deep into the body due to the skin effect (a phenomenon where high-frequency electricity flows only on the surface of a conductor); therefore, low-frequency TENG is suitable.

[0052] The implantable device includes a nerve stimulation portion, and the nerve stimulation portion includes an electrode portion that surrounds or is wrapped around the nerve, and nerve stimulation is possible through this nerve stimulation portion. Meanwhile, the implantable device includes an implantable medical device. In this case, the second electrode may be directly connected to an organ inside the human body instead of the implantable device inserted inside the human body. For example, the organ inside the human body may be a affected area such as a nerve or brain.

[0053] In this invention, experiments were conducted using small animals (rats) to verify the feasibility of using the human body as a single conductor. Energy was generated in a specific frequency band using a triboelectric generator and measured. Subsequently, this energy was transmitted wirelessly through the rat's body and measured to confirm that energy generated externally can be transmitted wirelessly through the skin, fat, and muscle layers. At this time, a biocompatible electrode attached to the rat's skin (external) was designated as the "transmitting electrode" to send energy received from the "energy generation unit (TENG)" into the body, while the part inserted inside the rat's body to receive energy was designated as the "receiving electrode." (In the case of the receiving electrode, a conductive electrode is essential for concentrating energy. Additionally, it was confirmed that efficiency can be further enhanced by performing additional earthing on the TENG externally, as shown in Fig. 7.)

[0054] A triboelectric energy generator based on triboelectric energy harvesting technology was fabricated, and wireless power communication was conducted through the body to obtain the results shown in Figure 4. It was confirmed that the voltage and current values ​​transmitted into the body through human body communication were transmitted with an efficiency of over 90% compared to the voltage and current of the triboelectric energy generator. This confirmed that the human body can operate as an RC circuit and that AC energy can pass through it.

[0055] The effect of the depth of the receiving electrode inserted into the body on the efficiency of wireless power communication was examined (see Fig. 8). After attaching the transmitting electrode to the skin of a pig, the receiving electrode was positioned at different depths in the fat and muscle layers of the pig to compare the energy power communication efficiency. Regardless of the distance over which power communication was conducted, the energy communication efficiency exceeded 90%, and the validity of the data was verified by repeating the measurements multiple times.

[0056] In addition, it was confirmed that the capacitor was charged by conducting wireless power communication through the body (see Fig. 9). The electrodes presented in this invention are broadly classified into three types: a transmitting electrode (Input electrode) attached to the skin, and a receiving electrode (Implanted electrode) that receives energy within the body through human body communication. The receiving electrode (Implanted electrode) inserted into the body can be composed of biodegradable materials. The receiving electrode (Implanted electrode) can be composed of biodegradable metallic materials (e.g., Mg, Mo, etc.). As confirmed by the charging of the capacitor as shown in Fig. 9, it is expected that devices inserted into the body can also be charged using this technology.

[0057] Experiments were conducted to verify the safety of wireless power communication through the human body (refer to Fig. 10). Small animals (mice) were used for the safety verification experiment, and electrical energy generated from triboelectric generators was applied through the mice's skin to the skin-fat-muscle layers. The safety of the power communication was confirmed through MRI and H&E analysis. The results showed that when electrical energy generated from the triboelectric generators was applied, muscle swelling or electrical perforation, which typically appear as symptoms of electric shock, was not detected in the MRI analysis. Furthermore, when cross-sections of the skin and muscles were examined through tissue biopsy H&E analysis, no vacuuming or hypercontraction was detected. As no necrosis or damage occurred at the cellular level, it is determined that power communication using triboelectric generators through the human body is safe for the human body.

[0058] As shown in Fig. 11, an experiment was conducted to implement a wireless power communication-based neurotherapy system through the human body. The sciatic nerve was damaged in small animals (mice) for verification, and electrical energy generated from triboelectric generators was applied through the mouse's skin to the skin-fat-muscle layer. The efficiency of nerve regeneration was confirmed through rotarod experiments and Semithin. It was confirmed that the treatment of the sciatic nerve in the communicating small animals was further accelerated.

[0059] Although the present invention has been described above with reference to preferred embodiments, those skilled in the art will understand that various modifications and changes can be made to the invention without departing from the spirit and scope of the invention as set forth in the following claims.

Claims

Claim 1 delete Claim 2 delete Claim 3 A human body-based power transmission triboelectric generator comprising: a triboelectric generator attached to the human body through a first electrode; a second electrode inserted into the human body; and an implantable device inserted into the human body connected to the second electrode, wherein electrical energy is generated from the triboelectric generator by the movement of the human body, and the generated electrical energy is supplied to the implantable device through the human body, wherein the implantable device includes a nerve stimulation part, and the nerve stimulation part directly surrounds the nerve so that nerve stimulation is possible through such nerve stimulation part, wherein the second electrode includes a receiving electrode and additionally includes a semi-grounding electrode, wherein the semi-grounding electrode has its outer surface coated with a non-conductive material so that the movement of electric charge is possible only through a wire, thereby improving the stability and grounding efficiency of human body-based power transmission, and wherein the electrical energy exhibits an alternating current frequency of 10 Hz or less, enabling long-distance transmission within the human body. Claim 4 delete Claim 5 In claim 3, the receiving electrode is a human-based power transmission triboelectric generator made of a biodegradable material. Claim 6 delete Claim 7 delete Claim 8 delete Claim 9 In claim 3, the current generated by the triboelectric generator is transmitted to the human body and exits through a ground electrode, a human body-based power transmission triboelectric generator. Claim 10 delete Claim 11 delete

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