Human body-coupled friction power wireless transmission technology

Abstract

The present invention relates to a technology for converting energy (kinetic energy and biomechanical energy) discarded to the surroundings into electrical energy through an energy harvesting technology, and utilizing the body as a power communication medium to transmit the energy to a necessary part anywhere inside or outside the body, and an application thereof. The present invention suggests a wireless power communication technology which does not require a separate wire connection between a power generator and a battery, thereby solving the power line problem of existing energy harvesting and accelerating commercialization of the energy harvesting technology.

Description

Human body-coupled friction power wireless transmission technology

[0001] The present invention relates to a technology and application thereof for converting energy (kinetic energy and biomechanical energy) wasted in the surroundings into electrical energy through energy harvesting technology, and transmitting power to any necessary part within or outside the body by utilizing the body as a power communication medium.

[0002] To enhance convenience in daily life, various wearable devices (healthcare and entertainment) are being actively developed, and commercialized products such as earbuds and smartwatches are also being released. Wearable devices are being developed with the goal of reducing discomfort while wearing them, making them lighter and more compact. Consequently, battery size is also shrinking, leading to capacity constraints.

[0003] The lightweight and miniaturized nature of wearable devices has led to limitations in battery capacity, resulting in shorter operating times and charging cycles, which can be inconvenient for users. To address this, energy harvesting technologies that enable charging while worn or in use are being proposed as a new energy solution. However, energy harvesting-based charging requires a wired connection between the wearable device and the energy harvester, which limits movement. Wireless transmission technologies based on electromagnetic waves and radio frequencies have been proposed to address this issue. However, these technologies are not practical solutions due to concerns about human health risks, low efficiency, and interference from the human body.

[0004] Meanwhile, to meet the societal demand for longevity and disease-free living, demand for implantable medical devices and treatments utilizing electrical energy is exploding. Currently, commercially available implantable medical devices generate electrical signals from a power source consisting of a battery and circuitry. Conventional battery-powered neural stimulators require replacement surgery when the battery discharges, resulting in significant social costs. Furthermore, battery limitations make it difficult to reduce the size or shape of the devices beyond a certain size.

[0005] To solve the problems described above, battery-free implantable nerve stimulators are being studied. However, the wireless communication technologies mainly used, such as RFID and NFC, have short transmission distances and have not been proven to be harmless to the human body. In addition, electromagnetic waves cannot penetrate metal packaging materials and are affected by the human body (body shadowing effect), which limits their commercialization. While the need for energy generation and transmission within the body to perform various functions such as real-time monitoring and treatment is increasing, the development of internal energy solutions is progressing only to a limited extent. Therefore, the need for the development of new internal energy solutions for electrical stimulation that are harmless to the human body and can maximize therapeutic efficacy is emerging.

[0006] The present invention aims to provide a new, high-efficiency energy solution that is harmless to the human body by continuously transmitting electric energy produced by energy harvesting to a desired location by using the human body as an energy transmission medium, thereby implementing various application technologies both inside and outside the body.

[0007] A human body-based frictional power wireless transmission method according to one embodiment of the present invention comprises: a frictional power generator attached to a human body through a first electrode; and a wearable device attached to the human body through a second electrode, wherein electric energy is generated in the frictional power generator by movement of the human body, and the generated electric energy is supplied to the wearable device through the human body, and the second electrode includes a receiving electrode.

[0008] The above electric energy represents an alternating current frequency of 1 kHz or less.

[0009] A human body-based frictional power wireless transmission method according to an additional embodiment of the present invention comprises: a frictional power generator attached to a 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 electric energy is generated in the frictional power generator by movement of the human body, and the generated electric energy is supplied to the implantable device through the human body, and the second electrode includes a receiving electrode.

[0010] The above electric energy represents an alternating current frequency of 1 kHz or less.

[0011] The above receiving electrode is made of a biodegradable material.

[0012] The current generated by the above triboelectric generator is transmitted to the human body and can escape through the ground electrode.

[0013] A human body-based frictional power wireless transmission method according to one embodiment of the present invention comprises: a frictional power generating element attached to a human body via a first electrode; and a second electrode inserted into the human body, wherein the second electrode can be connected to an organ within the human body, and electrical energy is generated from the frictional power generating element by movement of the human body, and the generated electrical energy is transmitted to the organ within the human body via the human body, and the second electrode includes a receiving electrode. In this case, the organ within the human body may be a diseased part such as a nerve or a brain.

[0014] A human body-based frictional power wireless transmission method according to an additional embodiment of the present invention comprises: a frictional power 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 current generated by the frictional power generator is transmitted to a human body base and can be stored as current through a charging circuit of the charging unit.

[0015] The above electric energy represents an alternating current frequency of 1 kHz or less.

[0016] The present invention proposes a wireless power communication technology that does not require a separate wire connection between a power generator and a battery, and it is expected that this will accelerate the commercialization of energy harvesting technology by solving the power line problem of existing energy harvesting.

[0017] In the present invention, the connection between the power generator and the wearable device is replaced with the human body. This technology enables the same power communication not only to a specific body part but also to any body part, making it applicable to various wearable devices. Therefore, it is expected that the battery operating time of wearable devices and sensors, which are in increasing demand in daily life, will be improved, thereby meeting the increasing energy demand. It is expected that it can be applied to all energy harvesting technologies that generate alternating current, leading to the commercialization of various energy harvesting technologies. Furthermore, the triboelectric energy (friction current) generated from the triboelectric power generator can be transmitted through the human body and can escape through the ground, as shown in Figure 1.

[0018] Furthermore, the present invention proposes a wireless power communication technology through the human body that eliminates the need for a separate wire connection between a power generating device and an electrode inserted into the human body. In particular, it can overcome the battery replacement problem of implantable medical devices and the limitations of electrical stimulation therapy due to the limitations of the internal energy transmission method (RF). Through this, it is expected that the power line problem of existing energy harvesting can be solved, thereby accelerating the commercialization of energy harvesting technology. In the present invention, the connection between the power generating device and the electrode inserted into the human body is replaced with the human body, thereby eliminating the discomfort or risk of disconnection of the wires between the power generating device and the implantable device. In addition, the battery replacement problem, which has been pointed out as a limitation of existing implantable medical devices, can be solved, thereby minimizing the risk to the patient. The present invention has the advantage of being able to manufacture the electrode inserted into the human body with a limited lifespan, thereby eliminating the need for re-surgery to remove the implantable device and electrode, which has caused a social and economic burden on patients in implantable medical devices.

[0019] FIG. 1 and FIG. 2 illustrate schematic diagrams of a human body-based friction power wireless transmission method according to one embodiment of the present invention.

[0020] Figure 3 illustrates a graph of wireless power communication outside the body via a function generator.

[0021] FIG. 4 illustrates a graph of voltage and current of wireless power communication in the human body using a human body-based frictional power wireless transmission method according to one embodiment of the present invention.

[0022] FIG. 5 illustrates a human body external wireless power communication voltage and current graph using a human body-based friction power wireless transmission method according to one embodiment of the present invention.

[0023] Figure 6 shows a graph of human body wireless power transmission efficiency according to body part outside the body.

[0024] Figure 7 shows the types of grounding electrodes when connecting to a device via wireless power communication outside the body.

[0025] 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.

[0026] Figure 9 illustrates capacitor charging via body-to-body wireless power communication.

[0027] Figure 10 is a stability test diagram of human body wireless power communication.

[0028] Figure 11 is a diagram showing the confirmation of nerve regeneration based on wireless power communication in the body.

[0029] FIG. 12 is a drawing explaining a mechanism for wireless power transmission within the body through energy harvesting according to the present invention.

[0030] Figure 13 illustrates a novel wireless neuromodulation technology using body-coupled triboelectric power transfer (TEPT), which uses the human body as a transmission medium and frictional energy harvesting as an energy source.

[0031] Figure 14 is a diagram showing the inherent tendency of electric current flowing through the body to follow the path of least resistance.

[0032] Various embodiments are now described with reference to the drawings, wherein like reference numerals are used throughout the drawings to designate like elements. For purposes of explanation, various descriptions are provided herein to facilitate an understanding of the present invention. However, it will be apparent that these embodiments may be practiced without these specific descriptions. In other instances, well-known structures and devices are presented in block diagram form to facilitate the description of the embodiments.

[0033] Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings. The present invention is susceptible to various modifications and variations, and thus 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 a specific disclosed form, but rather to encompass all modifications, equivalents, and alternatives falling within the spirit and technical scope of the present invention. Throughout the description of each drawing, similar reference numerals have been used to designate similar components.

[0034] The terminology used in this application is only used to describe specific embodiments and is not intended to limit the present invention. The singular expression includes the plural expression unless the context clearly indicates otherwise. In this application, it should be understood that the terms "comprise" or "have" indicate the presence of a feature, step, operation, component, part, or combination thereof described in the specification, but do not preclude the possibility of the presence or addition of one or more other features, steps, operations, components, parts, or combinations thereof.

[0035] The energy harvesting technology for wireless power communication within the human body proposed in the present invention utilizes the human body as a conductor, enabling energy generated outside the body to be transmitted to a desired location within the body. Among energy harvesting technologies, triboelectric energy harvesting, in particular, involves friction between different materials, generating frictional charges. The generated frictional charges are compensated for by changes in the distance between the frictional materials, and these charges travel through an external conductor, generating current. While various movements of the human body can drive triboelectric generators, a triboelectric generator that utilizes the force generated by the soles of the feet during walking is utilized for high mechanical energy generation. The present invention can transmit frictional energy (frictional current) generated through the human body, and this frictional current can be concentrated on a receiving electrode and then released through the Earth's ground.

[0036] The part that converts energy generated by human movement into electrical energy can be called the energy generation unit, and the electrical energy thus converted can be transmitted to various locations inside and outside the body using the human body as a conductor. The electrical energy transmitted inside the body can then be released back out through grounding with the Earth. The electrical energy transmitted through wireless power communication can also be stored in an energy storage device such as a battery in the energy consumption unit.

[0037] The present invention is divided into in-vivo application technology and in-vivo application technology, and specifically, in-vivo application technology includes a high-power alternating current energy harvesting element, a body-attachable electrode, a body-based wireless power communication, a power management integrated circuit (PMIC) that converts alternating current into direct current and converts it into an appropriate amount of energy for an electronic device, etc.

[0038] Below, we will first explain in vitro application techniques, followed by in vivo application techniques. In this case, any overlapping information will be omitted.

[0039] A human body-based frictional power wireless transmission method corresponding to an extracorporeal application technology according to one embodiment of the present invention can be achieved through a frictional power generator attached to the human body through a first electrode; and a wearable device attached to the human body through a second electrode.

[0040] As shown in FIGS. 1 and 2, the triboelectric generator can be directly attached to the human body via the first electrode, and the wearable device can be directly attached to the human body via the second electrode.

[0041] Triboelectric generators can take various forms, including push-type, rotating, or sliding types. They are attached to the human body via electrodes. To ensure stability and operating efficiency, various electrodes, such as metal or conductive hydrogel, can be directly attached to the human body. While these electrodes can be directly attached to the human body, they can also be indirectly attached, often by connecting short wires to other electrodes already attached to the body.

[0042] Wearable devices operate by utilizing output generated and transmitted through human-based frictional power wireless transmission. A wide variety of devices are available. These wearable devices are also attached directly to the body via electrodes. To ensure stability and operating efficiency, various types of electrodes, such as metal or conductive hydrogel, can be used.

[0043] The frictional electric generator generates electrical energy through the movement of the human body, and the generated electrical energy is transmitted through the human body to the wearable device. In this case, although not shown, an additional rectifier and energy storage unit may be included, and the generated energy may be passed through the rectifier and stored in the energy storage unit for use by the wearable device when needed. The energy storage unit refers to a charging unit, and this charging unit may be configured as a charging circuit.

[0044] Meanwhile, the triboelectric generator of the present invention is preferably attached to the sole of the foot. This is because the sole of the foot is where the greatest mechanical displacement and force are concentrated during human movement, allowing for a large output from the triboelectric generator. However, the device is not limited to the sole of the foot and can be attached to any location on the human body. Furthermore, multiple triboelectric generators may be installed, and multiple wearable devices may also be used.

[0045] The second electrode includes a receiving electrode. A separate ground electrode may exist, but is generally not necessary because it is grounded to the Earth. Therefore, frictional current is transmitted through the human body, concentrated at the second electrode (the receiving electrode), and then utilized before escaping through the ground.

[0046] The electrical energy generated in the triboelectric generator by the movement of the human body is low frequency, representing an alternating current frequency of several Hz, less than 1 kHz or preferably less than 10 Hz.

[0047] Figure 3 shows a method for verifying whether the human body can be used as a single conductor using a function generator. After generating and measuring energy in a certain frequency band using a function generator, the energy was transmitted wirelessly through the human body and measured to verify that the energy could be transmitted as power. At this time, bio-attachable electrodes were attached to both sides of the human body, and one side was named a 'transmitting electrode' that received energy from the 'energy generating unit' and sent it to the human body, and the other side was named a 'receiving electrode' that transferred the received energy to the 'energy using unit', and the usability was verified in this way.

[0048] Through Figure 5, it was confirmed that the voltage and current values ​​of triboelectric energy harvesting in extracorporeal applications and those of the voltage and current values ​​after human power communication were transmitted with an efficiency of nearly 90%. This confirms that the human body, with its water content including bodily fluids and blood, can function as an RC circuit and allow AC energy to pass through, and it was analyzed that the efficiency is high because the human body is similar.

[0049] In addition, the influence of wireless power communication according to distance was confirmed as shown in Fig. 6. After attaching the transmitting electrode to the left hand, the energy power communication efficiency was compared when the receiving electrode was positioned on the arm, neck, head, ankle, and right hand. Regardless of the distance over which power was communicated, the energy communication efficiency was over 90% in all cases, and the validity of the data was verified by repeating the measurement more than 3 times.

[0050] In addition, when using a ground electrode, it was confirmed that the efficiency of charging an energy storage device such as a battery increased when the ground electrode was used in the energy consumption unit, as shown in FIG. 7. The electrodes proposed in the present invention are broadly divided into three types: an earth ground electrode that directly performs grounding, and a semi-ground electrode that performs the function of grounding. The semi-ground electrode is a metal electrode that is externally coated with a non-conductive material to limit the movement of charges only through the wire. The non-conductive material is manufactured through a deposition process using a liquid material. The air ground electrode is designed to be compensated for by electrons in the air, and grounding is possible through a discharge effect. While the ground electrode provides the highest efficiency because it performs direct grounding, it is inconvenient to use because it requires grounding through an additional external wire. Therefore, in the present invention, in addition to the ground electrode, an air ground electrode and a semi-ground electrode are proposed to maintain the charging efficiency in the energy generation unit. While air-grounded electrodes can solve the problem of external wiring, they suffer from low efficiency. The proposed quasi-grounded electrode, however, can address the low efficiency of air-grounded electrodes by using a non-conductive material to replace air. The non-conductive material can be as thick as several μm to several tens of μm. These grounding electrodes can be omitted.

[0051] So far, we have explained the in vitro application technology, and below, we will explain the in vivo application technology.

[0052] A human-based frictional power wireless transmission method corresponding to an in-body application technology according to one embodiment of the present invention comprises: a frictional power generator attached to the human body via 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 within the human body instead of the implantable device inserted into the human body. For example, the organ within the human body may be a diseased area such as a nerve or brain.

[0053] The triboelectric generator is attached directly to the human body via a first electrode.

[0054] The implantable device is inserted into the human body and is connected to a second electrode inserted into the human body. The second electrode includes a receiving electrode.

[0055] In this case, the receiving electrode may be made of a biodegradable material.

[0056] The frictional electric generator generates electrical energy through human movement, and the generated electrical energy can be supplied to an implantable device through the human body. In this case, the electrical energy is low-frequency, representing an alternating current frequency of several Hz, typically 1 kHz or less, and preferably 10 Hz or less.

[0057] As shown in Fig. 12, wireless power transmission within the body is possible through energy harvesting. Currents with low Hz AC frequencies, such as 10 Hz or less, have long wavelengths and can be efficiently transmitted anywhere within the body. Energy with frequencies in the low Hz range has good human penetration, enabling longer distance transmission, as confirmed through experiments on pork and rats. Meanwhile, capacitive coupling occurs outside the body, as shown in the lower right diagram of Fig. 12. In this case, electro-quasistatic capacitive coupling is a wireless transmission technology that utilizes low-frequency electric fields, and in this case, floating or earth is usually used as the ground. Additionally, high frequencies above 1 kHz cannot penetrate deep into the body due to the skin effect (a phenomenon in which high-frequency electricity flows only on the surface of a conductor), making them unsuitable for in-body transmission. Low-frequency TENGs are more appropriate.

[0058] An implantable device includes a nerve stimulator, which includes an electrode that surrounds or is wound around a nerve, enabling nerve stimulation. Meanwhile, an implantable device includes an implantable medical device. In this case, the second electrode may be directly connected to an organ within the body, rather than the implantable device itself. For example, the organ may be a diseased area such as a nerve or the brain.

[0059] In this invention, experiments were conducted using a small animal (rat) to verify the feasibility of utilizing the human body as a single conductor. Using a triboelectric generator, energy was generated and measured at a specific frequency band. This energy was then transmitted wirelessly through the rat's body and measured. This confirmed that energy generated externally could be transmitted wirelessly through the skin, fat, and muscle layers. A bioadhesive electrode was attached to the rat's skin (external to the body) to transmit energy received from the "energy generating unit (TENG)" into the body, designated as the "transmitting electrode." The part inserted inside the rat's body (internally) to receive the energy was designated the "receiving electrode." (For the receiving electrode, a conductive electrode is essential for concentrating energy. Furthermore, if the TENG is additionally grounded externally, a method such as that shown in Figure 7 can further enhance efficiency.)

[0060] We developed a triboelectric energy generator based on triboelectric energy harvesting technology and performed wireless power communication through the body, achieving the results shown in Figure 4. We confirmed that the voltage and current values ​​transmitted to the body through human communication were over 90% efficient compared to the voltage and current of the triboelectric energy generator. This confirms that the human body can operate as an RC circuit and that AC energy can pass through it.

[0061] The depth of the receiving electrode inserted into the body affected the efficiency of wireless power communication (see Fig. 8). The transmitting electrode was attached to the pork skin, and the receiving electrode was positioned at various depths within the pork's fat and muscle layers to compare the energy communication efficiency. Regardless of the distance of power communication, the energy communication efficiency was consistently over 90%, and the validity of the data was verified by repeating the measurement multiple times.

[0062] In addition, it was confirmed that the capacitor was charged by conducting wireless power communication through the body. (See Fig. 9) The electrodes proposed in the present invention are largely divided into three types: a transmitting electrode (Input electrode) attached to the skin, and a receiving electrode (Implanted electrode) that receives energy from the body through human communication. The receiving electrode (Implanted electrode) inserted into the body may be composed of a biodegradable material. In the case of the receiving electrode (Implanted electrode), it may be composed of a biodegradable metal material (ex. Mg, Mo, etc.). As it was confirmed that the capacitor was charged as shown in Fig. 9, it is expected that devices inserted into the body will also be able to be charged using this technology.

[0063] An experiment was conducted to verify the safety of wireless power communication through the human body (see Fig. 10). A small animal (mouse) was used for the safety verification experiment, and the electrical energy generated from the triboelectric generator was applied through the mouse's skin to the skin-fat-muscle layer, and the safety of the power communication was confirmed through MRI and H&E analysis. As a result, muscle swelling or electrical perforation, which are usually symptoms of electric shock, were not found in the MRI analysis when the electrical energy generated from the triboelectric generator was applied. In addition, when the cross-sections of the skin and muscles were examined through tissue biopsy H&E analysis, neither vacuumization nor hypercontraction was found. Since no necrosis or damage occurred at the cellular level, it is believed that power communication through the human body using the triboelectric generator is safe for the human body.

[0064] As shown in Figure 11, we conducted an experiment to implement a wireless power communication-based nerve treatment system through the human body. The sciatic nerve of a small animal (mouse) was damaged, and electrical energy generated from a triboelectric generator was applied through the mouse's skin, extending to the skin-fat-muscle layer. The effectiveness of nerve regeneration was confirmed through a rotarod experiment and Semithin. It was confirmed that sciatic nerve treatment in the small animal that received the communication was further accelerated.

[0065] Figure 13 illustrates a novel wireless neuromodulation technology utilizing body-coupled triboelectric power transmission, which uses the human body as a transmission medium and triboelectric energy harvesting as an energy source. The human body, rich in extracellular fluid, has low resistance, minimizing loss when frictional current flows through it. Frictional currents below 1 kHz flow solely into the extracellular fluid, resulting in minimal loss. However, frictional currents above 1 kHz pass through cell walls, resulting in significant loss. Based on this, low-frequency (long-wavelength) triboelectric currents below 1 kHz were selected as the energy source for body-coupled TEPT, thereby improving PTE. Triboelectric currents can pass through the human body due to the potential difference between the ground and the transmitter.

[0066] Figure 14 is a diagram illustrating the inherent tendency of current flowing through the body to follow the path of least resistance. When a receiving electrode with lower resistance than the body is inserted, the frictional current from the transmitter is concentrated on the receiving electrode. Consequently, wireless neuromodulation technology based on body-coupled TEPT facilitates effective electrical stimulation of target tissues, enabling accurate treatment results through minimally invasive and simple procedures.

[0067] Although the present invention has been described above with reference to preferred embodiments thereof, it will be understood by those skilled in the art that various modifications and changes may be made to the present invention without departing from the spirit and scope of the present invention as set forth in the claims below.

Claims

1. A triboelectric generator attached to the human body via a first electrode; and A wearable device attached to the human body via a second electrode, Electric energy is generated in the frictional electric generator by the movement of the human body, and the generated electric energy is supplied to the wearable device through the human body. The second electrode comprises a receiving electrode, Human body-based friction power wireless transmission method.

2. In paragraph 1, The above electric energy represents an alternating current frequency of 1 kHz or less, Human body-based friction power wireless transmission method.

3. A triboelectric generator attached to the human body via a first electrode; a second electrode inserted into the human body; and Including an implantable device inserted into the human body connected to the second electrode, Electric energy is generated in the frictional electric generator by the movement of the human body, and the generated electric energy is supplied to the implantable device through the human body. The second electrode comprises a receiving electrode, Human body-based friction power wireless transmission method.

4. In paragraph 3, The above electric energy represents an alternating current frequency of 1 kHz or less, Human body-based friction power wireless transmission method.

5. In paragraph 3, The above receiving electrode is made of a biodegradable material, Human body-based friction power wireless transmission method.

6. In paragraph 3, The above implantable device includes a nerve stimulator, and the nerve stimulator includes an electrode part that surrounds or is wrapped around a nerve, and nerve stimulation is possible through the nerve stimulator. Human body-based friction power wireless transmission method.

7. In paragraph 3, The current generated by the above frictional electric generator is transmitted to the human body and exits through the ground electrode. Human body-based friction power wireless transmission method.

8. A triboelectric generator attached to the human body via a first electrode; and Contains a charging unit attached to the human body via a second electrode, Electric energy is generated in the frictional electric generator by the movement of the human body, and the generated electric energy is supplied to the charging part through the human body. The second electrode comprises a receiving electrode, The current generated by the above frictional electric generator is transmitted to the human body and can be stored as current through the charging circuit of the charging unit. Human body-based friction power wireless transmission method.

9. In paragraph 8, The above electric energy represents an alternating current frequency of 1 kHz or less, Human body-based friction power wireless transmission method.

10. A triboelectric generator attached to the human body via a first electrode; and comprising a second electrode inserted into the human body, The second electrode may be connected to an organ inside the human body, Electric energy is generated in the frictional electric generator by the movement of the human body, and the generated electric energy is transmitted to the organs inside the human body through the human body. The second electrode comprises a receiving electrode, Human body-based friction power wireless transmission method.

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