Energy harvesting device having electrostatic-based energy device and power management circuit integrated module, and method for performing same

Abstract

Disclosed are a method and device capable of miniaturizing a power management circuit used in an energy harvesting system, which is an objective of the present invention. To achieve the above-described objective, in the present embodiment, a conversion circuit unit is replaced with a leaky integrate-and-fire (LIF) element used for implementing an artificial neural network, thereby providing a single-substrate energy harvesting system integrated circuit. According to the present invention, the conversion circuit unit may be composed of a LIF element composed of a volatile threshold switching element and a thin film capacitor (Cm), and the volatile threshold switching element may be either a volatile memristor or a biristor.

Description

Energy harvesting device having an electrostatic-based energy device and a power management circuit integrated module, and a method for performing the same

[0001] The problem to be solved by the present invention is to provide a method and device capable of miniaturizing a power management circuit used in an energy harvesting system, and to provide a single-substrate energy harvesting system integrated circuit by replacing the conversion circuit part of the power management circuit with a LIF element conventionally used for implementing an artificial neural network.

[0002] With the recent surge in Internet of Things (IoT)-based knowledge services, a variety of related products and technologies are being introduced. Wireless charging and energy harvesting technologies, particularly those in wearable devices, biosensors, and wireless sensors, are undergoing active research and development, as they are key technologies that determine the product's usability. From a circuit perspective, research is being conducted on highly integrated and efficient circuits to maximize power efficiency while minimizing external components.

[0003] Energy harvesting refers to a technology that collects and uses environmental energy around a device, natural energy such as solar and wind, and regenerates energy by finding usable energy from discarded or unused resources, usually in the range of microwatts (㎼) to milliwatts (㎽).

[0004] Energy harvesting is categorized into various methods based on the method used to obtain energy. Methods for harvesting energy from nature include solar cells, which harvest energy from sunlight; thermoelectric devices, which harvest electrical energy from heat; piezoelectric devices, which harvest electrical energy from vibration; and RF, which harvest energy from electromagnetic waves. Recently, electrostatic-based energy devices, such as triboelectric nanogenerators (TENGs), which convert mechanical energy generated from physical vibration or friction into electrical energy by generating electromotive force through contact-electrification and electrostatic induction, have attracted significant attention due to their miniaturization, high output power, low cost, and diverse applicability.

[0005] Triboelectric nanogenerators typically consist of an upper layer composed of a metal electrode and a dielectric, while the lower layer consists solely of a metal electrode. Taking advantage of the metal electrode's tendency to positively charge compared to other dielectrics, a negatively charged dielectric is used as the upper layer's dielectric material. Therefore, when the upper and lower layers repeatedly contact and separate, causing friction, electrostatic induction causes the dielectric in the upper layer to become negatively charged, and the metal in the lower layer to become positively charged. Consequently, a charge density difference is created between the two electrodes, and when a wire is connected between them, current flows. While triboelectric nanogenerators are voltage sources capable of generating hundreds of volts, their internal impedance is relatively high, on the order of several MΩ. This results in low power output, typically on the order of microwatts (µW). Consequently, their low output current makes them difficult to use in real-time, direct powering of wireless electronic and electrochemical modules, which typically require milliamp-level currents. Alternatively, it can be used in conjunction with an intermittent power conversion circuit that temporarily stores power generated by external stimuli in a capacitor or similar device and releases it when the voltage exceeds a certain level. However, the use of such a complex, separate conversion circuit presents a problem: it fails to take advantage of the advantages (low cost, miniaturization) of triboelectric nanogenerators.

[0006] Meanwhile, recent advances in machine learning have led to the application of artificial neural networks in diverse fields, including image and pattern recognition. However, in the case of von Neumann-based deep neural networks, where a data bus between the memory and the CPU exists, the bus acts as a bottleneck, resulting in slow computational speeds and high power consumption. Therefore, Spike Neural Networks (SNNs), which perform learning and inference based on spike signals, similar to biological neurons, are being actively researched. To implement these SNNs in hardware, research is being conducted on Leaky Integration and Fire (LIF) devices, which accumulate current signals from previous layers and then fire signals when a threshold voltage is exceeded.

[0007] Meanwhile, the background technology described above is technical information that the inventor possessed for the purpose of deriving the present invention or acquired during the process of deriving the present invention, and cannot necessarily be said to be publicly known technology disclosed to the general public prior to the application for the present invention.

[0008] The problem to be solved by the present invention is to provide a method and device capable of miniaturizing a power management circuit used in an energy harvesting system.

[0009] In addition, another problem to be solved by the present invention is to provide a single-substrate energy harvesting system integrated circuit by replacing the conversion circuit part with a LIF element used for implementing an artificial neural network.

[0010] In addition, another problem to be solved by the present invention is to provide an energy harvesting system integrated circuit manufactured on a flexible substrate.

[0011] The tasks of the present invention are not limited to the tasks mentioned above, and other tasks not mentioned will be clearly understood by those skilled in the art from the description below.

[0012] The DC-DC converter included in the conventional conversion circuit and the undervoltage lockout (UVCL) or intermittent power transmission unit utilized to drive the converter generally have a complex required circuit structure, making miniaturization difficult or having a problem of difficulty in integration process on the same substrate as the triboelectric nanogenerator. Therefore, by replacing the conversion circuit with a LIF element used to implement an artificial neural network, a single-substrate energy harvesting system integrated circuit can be provided.

[0013] According to one of the problem solving means of the present invention, a method and device for implementing an energy harvesting system integrated circuit by miniaturizing a power management circuit used in an energy harvesting system can be provided.

[0014] In addition, according to any one of the problem solving means of the present invention, the conversion circuit used for energy harvesting can be replaced with a LIF element used for implementing an artificial neural network.

[0015] In addition, another problem that the present invention seeks to solve is to provide an energy harvesting system integrated circuit including an energy harvesting element and a power management circuit that can be manufactured on a flexible substrate.

[0016] The effects that can be achieved through the present invention are not limited to the effects mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art from the description below. Other effects that can be achieved or expected from embodiments of the present invention will be disclosed directly or implicitly in the detailed description of the embodiments of the present invention. For example, various effects expected according to embodiments of the present invention will be disclosed in the detailed description that follows.

[0017] Other aspects, advantages and salient features of the present invention will become apparent to those skilled in the art from the following detailed description, which discloses various embodiments of the present invention in connection with the accompanying drawings.

[0018] Aspects, features and advantages of specific embodiments of the present invention will become more apparent from the following description taken in conjunction with the accompanying drawings.

[0019] Figure 1 is a diagram illustrating a circuit for implementing a conventional energy harvesting system.

[0020] FIG. 2 is a drawing for explaining the switching characteristics of a LIF element according to one embodiment of the present invention.

[0021] FIGS. 3a and 3b are drawings illustrating an SCC circuit and an FSCC circuit according to one embodiment of the present invention.

[0022] FIG. 4 is a flowchart illustrating a method for implementing an energy harvesting system according to an embodiment of the present invention.

[0023] FIG. 5 is a diagram illustrating an energy harvesting system integrated circuit according to one embodiment of the present invention.

[0024] The present embodiments may be modified and have various embodiments. Specific embodiments are illustrated in the drawings and described in detail in the detailed description. However, this is not intended to limit the scope to specific embodiments, but should be understood to encompass various modifications, equivalents, and / or alternatives of the embodiments of the present invention. In connection with the description of the drawings, similar reference numerals may be used for similar components.

[0025] In describing the present invention, if it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the gist of the present invention, a detailed description thereof will be omitted.

[0026] Additionally, the following examples may be modified in various other forms, and the scope of the technical concepts of the present invention is not limited to these examples. Rather, these examples are provided to further faithfully and completely convey the technical concepts of the present invention to those skilled in the art.

[0027] The terms used in this invention are used solely to describe specific embodiments and are not intended to limit the scope of the rights. Singular expressions include plural expressions unless the context clearly indicates otherwise.

[0028] In the present invention, expressions such as “has,” “can have,” “includes,” or “may include” indicate the presence of a corresponding feature (e.g., a component such as a number, function, operation, or part), and do not exclude the presence of additional features.

[0029] In the present invention, expressions such as "A or B," "at least one of A and / or B," or "one or more of A or / and B" can include all possible combinations of the listed items. For example, "A or B," "at least one of A and B," or "at least one of A or B" can all refer to cases where (1) at least one A is included, (2) at least one B is included, or (3) both at least one A and at least one B are included.

[0030] The expressions “first,” “second,” “first,” or “second,” etc. used in the present invention can describe various components, regardless of order and / or importance, and are only used to distinguish one component from another, and do not limit the components.

[0031] When it is said that a component (e.g., a first component) is “(operatively or communicatively) coupled with / to” or “connected to” another component (e.g., a second component), it should be understood that the component may be directly coupled to the other component, or may be connected through another component (e.g., a third component).

[0032] On the other hand, when it is said that a component (e.g., a first component) is "directly connected" or "directly connected" to another component (e.g., a second component), it can be understood that no other component (e.g., a third component) exists between the component and the other component.

[0033] The expression "configured to" used in the present invention may be used interchangeably with, for example, "suitable for," "having the capacity to," "designed to," "adapted to," "made to," or "capable of." The term "configured to" may not necessarily mean only "specifically designed to" in terms of hardware.

[0034] Instead, in some contexts, the phrase "a device configured to" may mean that the device, in conjunction with other devices or components, is "capable of" performing A, B, and C. For example, the phrase "a processor configured (or set) to perform A, B, and C" may refer to a dedicated processor (e.g., an embedded processor) for performing those operations, or a general-purpose processor (e.g., a CPU or application processor) that can perform those operations by executing one or more software programs stored in a memory device.

[0035] In the embodiments, a 'module' or 'part' performs at least one function or operation, and may be implemented as hardware or software, or as a combination of hardware and software. Furthermore, a plurality of 'modules' or 'parts' may be integrated into at least one module and implemented as at least one processor, except for a 'module' or 'part' that needs to be implemented as a specific hardware.

[0036] Meanwhile, the various elements and areas in the drawings are schematically drawn. Therefore, the technical concept of the present invention is not limited by the relative sizes or spacing depicted in the attached drawings.

[0037] Below, the terms used in this specification are defined.

[0038] Energy harvesting is a technology that re-harvests wasted energy from the surroundings, such as light, heat, and vibration, and converts it into electrical energy for use. It refers to a technology that supplies power by converting various energy sources, such as photovoltaic or solar, piezoelectric, and thermal converters, into electrical energy without an external power supply.

[0039] An energy harvesting system refers to a system comprising an energy conversion unit that obtains energy in various ways, such as light, heat, and vibration, as described above, and a power management circuit for power management, or a circuit integrated with circuits for implementing such a system, and may additionally include a secondary battery for storing power. The power management circuit may include a rectifier circuit unit that includes a rectifier that converts alternating current to direct current, and a conversion circuit unit that includes a DC-DC converter, a capacitor, a switch, etc.

[0040] Electronic devices such as ICs each have different operating voltage ranges, so a DC-DC converter is a device that converts DC voltage to meet these needs. It may be a buck converter to lower the output voltage compared to the input voltage, a boost converter to increase the output voltage compared to the input voltage, or a buck-boost converter that combines the buck converter and the boost converter to perform both functions. In addition, an undervoltage lockout (UVLO) or other intermittent power transfer unit that stores a certain level of charge and intermittently transfers it to drive the converter may be included. Alternatively, it may be structured to consist only of an intermittent power transfer unit without the buck converter, boost converter, or buck-boost converter, and transfer the accumulated current directly to the load.

[0041] LIF (Leaky Integrate and Fire) devices are devices that can implement neuromorphic systems based on the principles of nerve cells. A neuromorphic system emulates the way the brain processes data by implementing neurons, which make up the human brain, using multiple devices. Neurons connect to other neurons through synapses and can receive data from other neurons through these synapses. Neurons accumulate and integrate the received data, and if the data exceeds a threshold, they fire and output it. In other words, neurons perform the function of accumulating and firing data. LIF devices are devices that implement this neuronal operation. They enter a low-resistance state and discharge a high current when the voltage exceeds a certain level, and switch to a high-resistance state when the voltage falls below a certain level.

[0042] Hereinafter, with reference to the attached drawings, an embodiment of the present invention will be described in detail so that a person having ordinary knowledge in the technical field to which the present invention pertains can easily carry out the present invention.

[0043] Figure 1 is a drawing for explaining a circuit for implementing a conventional energy harvesting system (100).

[0044] Referring to FIG. 1, a conventional energy harvesting system (100) may be composed of an energy conversion unit (110), a rectifier circuit unit (120), and a conversion circuit unit (130).

[0045] The energy conversion unit (110) may be configured as a device that generates current using photoelectric conversion that utilizes the phenomenon in which metals, etc., emit electrons when they absorb high-energy sunlight, piezoelectric conversion that utilizes the phenomenon in which positive and negative charges are divided when mechanical pressure is applied, in which the charge density on the surface changes and electricity flows when pressure is applied, electromagnetic wave conversion that collects electromagnetic waves, or thermoelectric conversion based on the Seebeck Effect that converts a temperature difference into a potential difference, or a triboelectric nanogenerator (TENG).

[0046] The rectifier circuit (120) may include an AC-DC rectifier circuit for changing the voltage waveform of the triboelectric nanogenerator, which generates a pulse-like AC voltage current waveform, into a DC form.

[0047] The conversion circuit unit (130) may include a DC-DC converter, a capacitor, a switch, and an intermittent power transmission unit, etc., for converting an input voltage that has passed through a rectifier into a specific output voltage. The DC-DC converter may generally be composed of a switch, a diode, an inductor, a capacitor, a load, etc., and when the voltage applied to the switch by the power transmission unit is higher than a preset voltage (turn-on voltage), it is turned on, and when it is lower than a preset voltage (turn-off voltage), it is turned off, so that the output voltage can be controlled. This switch may be a switch that is automatically controlled and operated, such as a power semiconductor switch, or may be a manually operated mechanical switch. In addition, the conversion circuit unit (130) may include a capacitor that plays a role in controlling the ripple of the input voltage of the DC-DC converter between the rectifier circuit unit (120) and the conversion circuit unit (130). Alternatively, it may be a structure that is composed only of an intermittent power transmission unit without a step-down converter, step-up converter, or step-up / step-down converter, and directly transmits the accumulated current to the load.

[0048] Since the DC-DC converter generally requires a complex circuit structure and has clear limitations in miniaturization of the circuit due to the inductor, there is a problem that a conventional conversion circuit unit (130) including a DC-DC converter cannot be integrated on the same substrate as an energy conversion unit (110) or a rectifier circuit unit (120). In addition, even if the conversion circuit unit is composed of only a conventional UVLO or intermittent power transmission unit, there is a problem that it is difficult to integrate it on the same substrate as an energy harvesting element.

[0049] The energy harvesting system (100) may additionally include a battery unit, which refers to a capacitor capable of storing energy to drive a specific application (140) through a conversion circuit unit, and may be composed of a secondary battery, etc. In addition, depending on the type of specific application, the battery unit may not be provided.

[0050] FIG. 2 is a drawing for explaining the switching characteristics of a LIF element according to one embodiment of the present invention.

[0051] Among the hardware components for implementing SNN (Spike Neural Network), the element that receives a current signal from the previous synaptic circuit and fires when the received current signal exceeds a certain level to transmit a voltage signal to the next synaptic circuit is called a LIF (leaky integrate-and-fire) element.

[0052] A LIF device can be composed of a volatile threshold switching device and a membrane capacitor (Cm). The volatile threshold switching device (hereinafter referred to as a "switching device") can be either a volatile memristor or a Si biristor. The volatile memristor can be a device using an NbOx-based insulator-metal transition (IMT), a device using a boron (B)-tellurium (Te)-based Ovonic Transition, or a device based on the principle of filament formation and migration of Ag ions (hereinafter referred to as an "Ag ion-based device"). In general, memristors have a nonvolatile property in which the recorded resistance value remains unchanged unless another electrical signal is input, but there are ionic effects due to the formation and movement of filaments of active metal ions (e.g., Ag, etc.) and Mott insulators (e.g., VO). 2, NbO2, etc.) can exhibit volatile properties depending on the thermal effect due to temperature changes. In addition, TiO2, SrTiO3, NiO, CuO, ZnO, MnOx, HfOx, Ta2O5, Ti2O 5-x / TiOy, TaOx / TiO 2-x Memristors based on thin films of transition metal oxides can also be used as switching elements.

[0053] The above switching elements have the characteristic of initially maintaining a high resistance state, and when an external current is applied, the charge is accumulated in Cm, and when the voltage accumulated in Cm exceeds the threshold voltage (Vth), the switching element switches to a low resistance state and discharges the charge accumulated in Cm. In addition, when the voltage during the discharge drops below the hold voltage (Vhold), the switching element switches back to a high resistance state and has the characteristic of stopping the discharge.

[0054] Previous research aimed to achieve low threshold voltage (Vth) and low capacitor capacitance (Cm) for low-power artificial neural networks. However, the present invention requires a high threshold voltage (Vth) and high capacitor capacitance (Cm) of the switching element to meet the voltage and current requirements of the application being driven, resulting in differences in purpose and effectiveness compared to previous research.

[0055] Specifically, the volatile memristor may be a Ag ion-based device. For example, the threshold voltage (Vth) of the Ag ion-based device disclosed in FIG. 2 is about 0.5 V, the hold voltage is about 0.3 V, and the threshold current (Ith) is 10 nA. The threshold voltage (Vth) and the threshold current (Ith) of the Ag ion-based device are determined according to the thickness, type, and process conditions of the dielectric film. Therefore, the upper and lower Ag electrodes are formed based on printed electronics technology, and the dielectric film is formed of titanium oxide (TiO2). , It can be formed through a deposition of an inorganic thin film such as hafnium oxide (HfO2) or a printed electronics process using Nafion. In this case, the hold voltage can be set to 0 V or higher, the threshold voltage can be set to a voltage higher than the hold voltage, and the threshold current can be set to approximately 1 mA for the operation of a specific application to be driven.

[0056] FIGS. 3a and 3b are drawings illustrating an SCC circuit and an FSCC circuit according to one embodiment of the present invention.

[0057] FIG. 3a is a diagram illustrating a switched-capacitor converter (SCC) composed of a capacitor and a switch, and FIG. 3b is a fractal switched-capacitor converter (FSCC) circuit in which two or more SCCs are arranged in series / parallel according to one embodiment.

[0058] Triboelectric nanogenerators can easily generate high voltages of several kV, but have low currents (~μA) and low charge densities (~100μC / m). 2 ) and high impedance (1 MΩ ~ 100 Ω), so the energy utilization efficiency is very low. Therefore, in order to maximize the energy generated from the triboelectric nanogenerator, a circuit that converts high voltage / low charge (Q) to low voltage / high charge (Q) is required.

[0059] A Switched-Capacitor Converter (SCC), which consists of a capacitor and a switch, can charge a series-connected capacitor and discharge the charged capacitor in parallel to convert a high voltage / low charge (Q) into a low voltage / high charge (Q). A Fractal Switched-Capacitor Converter (FSCC) circuit refers to a circuit that improves transfer efficiency by arranging two or more SCCs in series / parallel.

[0060] Unlike step-up / step-down converters, which require inductors and are difficult to integrate on flexible substrates, the diodes and capacitors used in FSCC circuits can be constructed from flexible materials that facilitate low-temperature, flexible substrate processing using printed electronics technology. Furthermore, the power transfer efficiency of FSCC circuits can exceed 80%.

[0061] FIG. 4 is a flowchart illustrating a method for implementing an energy harvesting system according to an embodiment of the present invention.

[0062] Voltage can be generated by an energy conversion device (such as a friction electric nanogenerator) of the energy conversion unit (S410).

[0063] If the generated voltage is an AC voltage, the AC voltage can be converted into a DC voltage through a rectifier circuit (S420). If the DC voltage is generated by an energy conversion device, the process of converting the AC voltage into a DC voltage (S420) can be omitted.

[0064] The converted DC voltage can be stepped down through the FSCC circuit (S425). This process (S425) can be performed for the purpose of converting a low charge (Q) into a high charge (Q) while stepping down a high-voltage input voltage into a low-voltage output voltage, and may be omitted.

[0065] When a DC voltage is applied to a capacitor connected in parallel and charge is stored in the capacitor, the capacitor voltage (Vcm) increases until it reaches the threshold voltage (Vth) of the switching element connected in parallel with the capacitor (S430). Before the input voltage applied to the switching element reaches the threshold voltage, the switching element is in the OFF state, the resistance value of the switching element is high enough that almost no current flows, and the leakage current value in that state can be 10 nA or less. This process is called charging.

[0066] When the capacitor voltage (Vcm) is higher than the threshold voltage (Vth) of the switching element, the resistance of the switching element decreases, the charge is discharged, current flows (the switching element is in the ON state), and the application directly connected to the switching element can be operated (S440). In this case, the threshold current (ignition current) may be 1 mA or more. In addition to the application directly connected to the switching element, a separate battery unit may be provided. This process is called discharging.

[0067] As the discharge progresses, when the capacitor voltage (Vcm) falls below the hold voltage (Vhold) of the switching element, the resistance of the switching element increases again (OFF state) and charging proceeds again.

[0068] FIG. 5 is a diagram illustrating an energy harvesting system integrated circuit according to one embodiment of the present invention.

[0069] An integrated circuit of an energy harvesting system (500) according to one embodiment of the present invention includes an energy conversion unit (510), a rectifier circuit unit (520), and a conversion circuit unit (540, 550), and may additionally include an FSCC circuit (530) and a target electronic element (application) to be driven (560).

[0070] The energy conversion unit (510) is a device that converts external energy into electric energy, and is not limited to its type. However, as an example, a triboelectric nanogenerator is described below. The triboelectric nanogenerator operates on the principles of triboelectric charging and electrostatic induction. Here, the triboelectric charging refers to an electric charging phenomenon that occurs when different materials come into contact and are separated. The triboelectric nanogenerator can be classified into a contact-separation mode, a sliding mode, a single-electrode mode, or a free-standing mode depending on the charging method. In the present invention, the effect of the invention does not change even if each charging method is different.

[0071] The rectifier circuit unit (520) may include a rectifier circuit for converting the voltage waveform of the triboelectric nanogenerator, which generates a pulsed AC voltage current waveform, into a DC form. The rectifier circuit may be either a full-wave rectifier circuit that converts the negative voltage component of the input voltage into a positive voltage by rectifying it into a DC by configuring diodes in a bridge-type circuit, or a half-wave rectifier circuit that cancels the negative voltage component of the input using a single diode and converts it into a DC. In addition, the diode of the rectifier circuit may be formed based on a flexible material such as PEDOT:PSS or an inorganic thin film that can be processed at low temperature on a flexible substrate using printed electronics technology.

[0072] The conversion circuit unit (540, 550) may be configured with a LIF (leaky integrate-and-fire) element according to the present invention. The LIF element may be configured with a volatile threshold switching element (550) and a thin film capacitor (540) (Cm). The volatile threshold switching element (550) may be either a volatile memristor or a biristor.

[0073] Additionally, the thin film capacitor (540)(Cm) is made of titanium dioxide (TiO2) , Based on inorganic thin film deposition and printed electronics technology such as hafnium oxide (HfO2), the capacitance per area is 1 nF / mm. 2 It could be strange.

[0074] The switching element (550) may be replaced with another switching element having a hold voltage of 0 V or more, a threshold voltage of the hold voltage or more, and a threshold current of about 1 mA, in addition to a volatile memristor such as an Ag ion-based element, and the values ​​of the required threshold voltage and threshold current may vary depending on the type of the electronic element (560) to be driven. In addition, if a battery unit is additionally included in the energy harvesting system (500), the values ​​of the required threshold voltage and threshold current may vary. The switching element (550) and the thin film capacitor (540) (Cm) may be materials that can be processed on a flexible substrate.

[0075] The energy harvesting system (500) may further include a Fractal design-based Switched-Capacitor Converter (FSCC) circuit (530) to increase transmission efficiency between the rectifier circuit (520) and the converter circuit (540, 550).

[0076] The energy harvesting system (500) may additionally include a battery unit, which refers to a capacitor capable of storing energy to drive an electronic element (560) to be driven through a conversion circuit unit (540, 550), and may be configured as a secondary battery, etc. In addition, depending on the type of the electronic element (560) to be driven, the battery unit may not be provided.

[0077] The energy conversion unit (510), rectifier circuit unit (520), and conversion circuit units (540, 550) constituting the energy harvesting system (500) can be integrated on a single substrate, and the FSCC circuit (530) can be additionally directly formed on the same single substrate. In addition, the single substrate can be a flexible substrate.

[0078] Although the preferred embodiments of the present invention have been illustrated and described above, the present invention is not limited to the specific embodiments described above, and various modifications can be made by a person having ordinary skill in the art to which the present disclosure pertains without departing from the gist of the present invention as claimed in the claims. Furthermore, such modifications should not be understood individually from the technical idea or prospect of the present invention.

Claims

1. In the energy harvesting system (500), An energy conversion unit (510) that generates an AC voltage using external energy; A rectifier circuit (520) connected in parallel with the energy conversion unit (510) and converting the AC voltage into a DC voltage; A conversion circuit (540, 550) connected in parallel with the above rectifier circuit (520) and generating an output voltage and output current based on the converted DC voltage; and It includes an electronic element (560) that is directly connected to the above-mentioned conversion circuit (540, 550) and driven based on the above-mentioned output voltage and output current. The above conversion circuit (540, 550) has a capacitor (540) and a switching element (550) connected in parallel, An energy harvesting system (500) characterized in that the switching element (550) is either a volatile memristor or a biristor.

2. In paragraph 1, An energy harvesting system (500) characterized in that the energy conversion unit (510) is a triboelectric nanogenerator.

3. In paragraph 1, An energy harvesting system (500), characterized in that the output voltage is a threshold voltage of the switching element (550), and the output current is a threshold current of the switching element (550).

4. In paragraph 1, The above capacitor (540) is a thin film capacitor and has a capacitance per area of ​​1 nF / mm. 2 An energy harvesting system (500) characterized by the above.

5. In paragraph 1, An energy harvesting system (500) characterized by further including a Fractal design-based Switched-Capacitor Converter (530) circuit connected in parallel between the rectifier circuit (520) and the converter circuit (540, 550).

6. In paragraph 1, An energy harvesting system (500) characterized in that the energy conversion unit (510), the rectifier circuit unit (520), and the conversion circuit unit (540, 550) are integrated on a single flexible substrate.

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