Deformable Complementary Moisture and Triboelectric Energy Harvester

Abstract

According to one embodiment of the present invention, an energy generator capable of generating high power complementarily through high current moisture induction power generation and high voltage triboelectric power generation in a single device can be manufactured.

Description

Technology Field

[0001] The present invention relates to a water-induced generator (MEG) and a triboelectric nanogenerator (TENG), and more specifically, to a deformable complementary water and tribo energy harvester using an MXene / organic ion hydrogel foam (MOHF). Background Technology

[0002] Since water is ubiquitous enough to cover two-thirds of the Earth's surface and about 10% of freshwater exists in the atmosphere in the form of clouds and fog, energy harvesting using water-induced generators (MEGs) is attracting significant interest. These blue energy harvesters convert chemical energy into electrical energy by utilizing the ion concentration gradient generated when water molecules are spontaneously adsorbed onto hygroscopic functional groups (-OH, -COOH, etc.) within asymmetric moisture control or chemical gradient structures, thereby releasing free-charged ions. Numerous studies have attempted to realize high-performance MEGs using various materials, such as surface-modified carbon, graphene oxide, cellulose-based materials, protein-based biomaterials, polymers, metal-organic frameworks, and metal oxides. However, current device-level current densities have not been satisfactory, and some devices require immersion in water, which presents disadvantages that make them unsuitable for application in portable and wearable electronic products.

[0003] Recently, significant progress has been made in the development of MEGs equipped with ionic hydrogels that possess excellent moisture capture and rapid ion transport capabilities through three-dimensional (3D) porous structures. MEGs equipped with ionic hydrogels efficiently overcome the total ion deficit problem of ionized water, thereby improving the output current of the device. Furthermore, due to their unique interactions with water molecules, ionic hydrogels can be used as water reservoirs that continuously supply hydrated ions over long periods. Meanwhile, to further enhance harvesting performance, MEGs can be effectively integrated with other energy harvesters. For example, high-performance MEG systems have been developed by integrating photosensitive phytochrome into hydrophilic polyelectrolytes. However, while these hybrid MEG systems have successfully harvested energy simultaneously from moisture and sunlight, hybrid MEG arrays are required for power enhancement because the output voltage is typically in the range of several hundred millivolts to about 1.0 V. Accordingly, the inventors anticipated that harvesters based on mechanical energy conversion, such as piezoelectricity and triboelectricity, could be good candidates for high-performance hybrid MEGs because they can easily generate high output voltages. MEGs equipped with unique ion-selective surfaces are particularly suitable for triboelectrification involving repetitive mechanical contact electrification, making it possible to create high-output hybrid MEGs equipped with triboelectric nanogenerators (TENGs). However, several issues must be addressed to develop such hybrid MEGs. First, energy harvesting must be avoided at high humidity, which is necessary for MEG operation, as the power efficiency of TENGs decreases significantly at high humidity. More importantly, the mechanical resilience and robustness of the hybrid MEG must be ensured so that the device can withstand severe deformation and repetitive contact. Prior art literature

[0004] Korean Intellectual Property Office Registered Patent Publication (B1) No. 10-2543736 (Published June 14, 2023) The problem to be solved

[0005] One objective of the present invention is to provide a device capable of solving the problem of difficulty in additional energy amplification, which is caused by the low mechanical properties of devices used in conventional moisture-induced power generation, making it difficult to integrate them with tribo-based energy generation devices.

[0006] In addition, one objective of the present invention is to provide more practical application examples by simultaneously utilizing direct current and alternating current systems, unlike simply driving commercially available electronic devices using moisture-induced power generation. means of solving the problem

[0007] According to one aspect of the present invention, an organo-ionic hydrogel foam is provided, comprising an MXene foam having a three-dimensional skeletal structure; and an organo-ionic hydrogel foam having an organo-ionic hydrogel coating a portion of the MXene foam, wherein a dry region not coated by the organo-ionic hydrogel is positioned on a wet region coated by the organo-ionic hydrogel.

[0008] According to another aspect of the present invention, a method for manufacturing an organo-ionic hydrogel foam is provided, comprising the steps of: manufacturing a MXene foam having a three-dimensional skeletal structure and containing MXene; and coating a portion of the MXene foam with an organo-ionic hydrogel.

[0009] According to another aspect of the present invention, a moisture-inducing generator is provided, comprising: the organic ionic hydrogel foam; a first conductive substrate disposed below the organic ionic hydrogel foam; and a second conductive substrate inserted into the drying region of the organic ionic hydrogel foam.

[0010] According to another aspect of the present invention, a triboelectric generator is provided comprising: the organic ionic hydrogel foam; a third conductive substrate disposed on top of the organic ionic hydrogel foam; and a fourth conductive substrate inserted into the drying region of the organic ionic hydrogel foam.

[0011] According to another aspect of the present invention, a moisture induction and triboelectric generator is provided, comprising: the organic ionic hydrogel foam; a fifth conductive substrate disposed below the organic ionic hydrogel foam; a sixth conductive substrate disposed above the organic ionic hydrogel foam; and a seventh conductive substrate inserted into the drying region of the organic ionic hydrogel foam, wherein the fifth conductive substrate, the organic ionic hydrogel foam, and the seventh conductive substrate generate direct current (DC) power by moisture induction generation, and the sixth conductive substrate, the organic ionic hydrogel foam, and the seventh conductive substrate generate alternating current (AC) power by triboelectric generation.

[0012] According to another aspect of the present invention, an emergency exit guidance system utilizing the moisture induction and triboelectric generator is provided, wherein the direct current (DC) power generated by the moisture induction generation is always switched on, and the alternating current (AC) power generated by the triboelectric generation is generated by the steps of people evacuating in an emergency situation. Effects of the invention

[0013] According to one embodiment of the present invention, an energy generator capable of generating high power complementarily through high current moisture induction power generation and high voltage triboelectric power generation in a single device can be manufactured.

[0014] In addition, according to one embodiment of the present invention, an energy generator capable of simultaneously generating DC and AC power can be substantially utilized and applied as a self-generating power system for an emergency escape indicator light. Brief explanation of the drawing

[0015] Figure 1 shows a characterization analysis of an MXene / organic ion hydrogel foam (MOHF) prepared according to one embodiment of the present invention. Figure 2 shows the electrical performance of an MEG-MOHF manufactured according to one embodiment of the present invention. Figure 3 shows the operating mechanism of an MEG-MOHF manufactured according to one embodiment of the present invention. Figure 4 shows the mechanical properties of MEG-MOHF manufactured according to one embodiment of the present invention. Figure 5 shows the electrical performance of a TENG-MOHF manufactured according to one embodiment of the present invention. Figure 6 shows the electrical performance of a complementary MEG-TENG-MOHF manufactured according to one embodiment of the present invention. FIG. 7 shows a method for manufacturing and using an emergency exit guidance system according to one embodiment of the present invention. Specific details for implementing the invention

[0016] The above objectives, other objectives, features, and advantages will be easily understood through the following preferred embodiments associated with the accompanying drawings. However, the embodiments described herein are not limited to those described herein and may be embodied in other forms. Rather, the embodiments introduced herein are provided to ensure that the disclosed content is thorough and complete and that the technical concept is sufficiently conveyed to a person skilled in the art.

[0017] In describing each drawing, similar reference numerals have been used for similar components. In the attached drawings, the dimensions of the structures are depicted enlarged from their actual size for clarity of the invention. Terms such as "first," "second," etc., may be used to describe various components, but said components should not be limited by said terms. These terms are used solely for the purpose of distinguishing one component from another. For example, without departing from the scope of the invention, the first component may be named the second component, and similarly, the second component may be named the first component. A singular expression includes a plural expression unless the context clearly indicates otherwise.

[0018] In this specification, terms such as "comprising" or "having" are intended to specify the existence of the features, numbers, 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, numbers, steps, actions, components, parts, or combinations thereof. Furthermore, when a part such as a layer, film, region, or plate is described as being "on" another part, this includes not only the case where it is "immediately above" the other part, but also the case where there is another part in between. Conversely, when a part such as a layer, film, region, or plate is described as being "below" another part, this includes not only the case where it is "immediately below" the other part, but also the case where there is another part in between.

[0019] Unless otherwise specified, all numbers, values, and / or expressions used herein to represent amounts of ingredients, reaction conditions, polymer compositions, and formulations should be understood to be modified by the term “approximately” in all cases, as these numbers are essentially approximations reflecting the various uncertainties of measurement that occur in obtaining these values ​​among other things. Furthermore, where numerical ranges are disclosed herein, such ranges are continuous and, unless otherwise indicated, include all values ​​from the minimum value of such range to the maximum value including said maximum value. Moreover, where such ranges refer to integers, they include all integers from the minimum value to said maximum value including said maximum value, unless otherwise indicated.

[0020] In this invention, a cationic selective two-dimensional (2D) MXene (Ti3C2T) is applied to an elastic 3D melamine foam. x A deformable complementary water and tribo-energy harvester with deposited flakes is disclosed. To ensure high performance of the MEG at low humidity, 1 / 5 of the MXene foam is coated with an organo-ionic hydrogel to continuously supply water and salt ions to the upper uncoated MXene surface. The hybrid harvester has a maximum output open-circuit voltage (V). OC ), short-circuit current density (J SC ), and power densities are approximately 310mV and 877μA cm⁻¹, respectively. -2 , and 9.15μW cm -2It exhibits MEG performance under various mechanical deformations. The elastic MXene / organo-ionic hydrogel foam according to the present invention is capable of withstanding more than 30,000 cycles of repetitive frictional contact, thereby providing stable TENG performance with an alternating current (AC) voltage of approximately 80 V. Complementary energy harvesting is performed in a single MXene / organo-ionic hydrogel foam (MOHF) device according to the present invention, with maximum voltage and current of 55 V, 102 μA, and approximately 83 μW cm⁻¹, respectively. -2 It is possible to achieve high power and excellent elasticity and compressive strength of approximately 30% and 2.1 MPa, respectively. In addition, a new optical emergency alarm and guidance system is disclosed that is driven by a complementary energy harvester according to the present invention equipped with a high-speed capacitor charging function. The DC light emitted by an alarm sensor powered in MEG mode is amplified into AC power in TENG mode harvested from a person's transient walking motion during an emergency, effectively guiding people to an exit.

[0021] According to one aspect of the present invention, an organo-ionic hydrogel foam is provided, comprising an MXene foam having a three-dimensional skeletal structure; and an organo-ionic hydrogel foam having an organo-ionic hydrogel coating a portion of the MXene foam, wherein a dry region not coated by the organo-ionic hydrogel is positioned on a wet region coated by the organo-ionic hydrogel.

[0022] According to one embodiment of the present invention, the maxim foam may have MXene flakes of a two-dimensional structure attached to a melamine foam of a three-dimensional structure.

[0023] According to one embodiment of the present invention, the organic ionic hydrogel may be based on polyacrylamide (PAM) containing glycerol and an ionic salt.

[0024] According to another aspect of the present invention, a method for manufacturing an organo-ionic hydrogel foam is provided, comprising the steps of: manufacturing a MXene foam having a three-dimensional skeletal structure and containing MXene; and coating a portion of the MXene foam with an organo-ionic hydrogel.

[0025] According to one embodiment of the present invention, the step of manufacturing the MXene foam may include the step of coating MXene flakes on the surface of the melamine foam.

[0026] According to one embodiment of the present invention, the step of coating with the organic ionic hydrogel may include the step of partially coating the MXene foam with an organic ionic hydrogel based on polyacrylamide containing glycerol and an ionic salt.

[0027] According to another aspect of the present invention, a moisture-inducing generator is provided, comprising: the organic ionic hydrogel foam; a first conductive substrate disposed below the organic ionic hydrogel foam; and a second conductive substrate inserted into the drying region of the organic ionic hydrogel foam.

[0028] According to another aspect of the present invention, a triboelectric generator is provided comprising: the organic ionic hydrogel foam; a third conductive substrate disposed on top of the organic ionic hydrogel foam; and a fourth conductive substrate inserted into the drying region of the organic ionic hydrogel foam.

[0029] According to another aspect of the present invention, a moisture induction and triboelectric generator is provided, comprising: the organic ionic hydrogel foam; a fifth conductive substrate disposed below the organic ionic hydrogel foam; a sixth conductive substrate disposed above the organic ionic hydrogel foam; and a seventh conductive substrate inserted into the drying region of the organic ionic hydrogel foam, wherein the fifth conductive substrate, the organic ionic hydrogel foam, and the seventh conductive substrate generate direct current (DC) power by moisture induction generation, and the sixth conductive substrate, the organic ionic hydrogel foam, and the seventh conductive substrate generate alternating current (AC) power by triboelectric generation.

[0030] According to another aspect of the present invention, an emergency exit guidance system utilizing the moisture induction and triboelectric generator is provided, wherein the direct current (DC) power generated by the moisture induction generation is always switched on, and the alternating current (AC) power generated by the triboelectric generation is generated by the steps of people evacuating in an emergency situation.

[0031] Hereinafter, the present invention will be described in more detail with reference to the attached drawings to aid in understanding the invention. However, the following examples are provided merely to facilitate a better understanding of the invention, and the content of the invention is not limited by the following examples.

[0032] [Example]

[0033] - Design and Characteristics of Complementary Harvesters Using MOHF

[0034] Figure 1 shows the characterization of an MXene / organic ion hydrogel foam (MOHF) prepared according to one embodiment of the present invention. Specifically, in Figure 1, (a) a schematic diagram of the designed MOHF structure and (b) a photograph of the MOHF. (c) a scanning electron microscope (SEM) image of the surface of the PVA / MXene-melamine foam structure (inset: high-magnification SEM image). (d) X-ray diffraction (XRD) analysis and (e) C1s X-ray photoelectron spectroscopy (XPS) spectrum of the PVA / MXene-melamine foam. (f) a comparison of the water retention capacity of the ionic and organic ion hydrogels over time under 20% relative humidity conditions. (g) a photograph of the flexible and deformable MOHF. (h) strain-tensile strength curves of the melamine foam, PVA / MXene-melamine foam, and MOHF. (i) Loading-unloading curve over 30 cycles at a maximum compressive strain of 95%.

[0035] MOHF was fabricated by partially injecting an organic ion hydrogel into dip-coated melamine foam following a series of dip-coating processes, as schematically illustrated in Fig. 1a. MXene flakes were dip-coated onto the surface of the melamine foam. A thin poly(vinyl alcohol) (PVA) film was subsequently coated onto the MXene-treated melamine foam to ensure adhesion with the organic ion hydrogel and to facilitate the transport of ionized water and ions from the salt dissolved in the organic ion hydrogel. The MOHF was produced by partially coating the PVA-treated MXene / melamine foam with a polyacrylamide (PAM)-based organic ion hydrogel containing glycerol and an ion salt (KCl). Melamine foam was selected as a structural framework that provides excellent resilience against various mechanical deformations associated with triboelectricity. The thin MXene film coated on the melamine foam had a large specific surface area and high electrical conductivity, ensuring high-performance water energy generation. The hydrophilic PVA coated on the MXene promoted the movement of ionized water and ions, thereby improving MEG performance. Finally, the organic ionic hydrogel with a unique 3D cross-linked hygroscopic polymer network acted as a water and ion reservoir, continuously supplying hydration ions and salt ions to the uncoated PVA / MXene-melamine foam, as schematically shown in Fig. 1a.

[0036] As shown in the photograph in Fig. 1b, the height of the MOHF is approximately 10 mm, and the bottom 2 mm is coated with an organic ion hydrogel. The thin MXene film coated on the melamine foam was examined using a scanning electron microscope (SEM), and the results in Fig. 1c show that the MXene flakes completely cover the melamine foam, creating a characteristic rough structure resulting from variations in the number of MXene flakes on the surface (see inset in Fig. 1c). The MXene flakes coated the melamine foam well, which is due to various terminal groups (T) on the MXene surfacex, = -OH, -O, -F) promoted strong electrostatic interactions with the terminal amine groups of the melamine foam. The coating of MXene multilayers on the melamine foam was confirmed by transmission electron microscopy (TEM) and energy dispersive X-ray spectroscopy (EDS) images of a cross- section of a single PVA / MXene-melamine backbone.

[0037] The PVA / MXene-melamine foam was further examined using high-resolution X-ray diffraction (HR-XRD) and high-resolution X-ray photoelectron spectroscopy (HR-XPS), and the results are shown in Figs. 1d and 1e, respectively. The HR-XRD results show a broad peak at 22.5° indicating the amorphous structure of the melamine foam and a sharp peak at 5.8° corresponding to the (002) reflection of the basal plane of Ti3C2. The amorphous nature of PVA is barely recognized in the HR-XRD results, which may be due to the low concentration of PVA. The C 1s HR-XPS result in Fig. 1e shows 281.5 eV (C-Ti-T) associated with MXene. X It displays notable peaks at ) and 284.5 eV (CC), 286.1 eV associated with the CO bonding of PVA, and 288.7 eV corresponding to the CN energy of melamine. O 1s and N 1s HR-XPS results further confirm the formation of a thin MXene layer as well as a PVA layer on the melamine foam.

[0038] The excellent water retention capacity of the organic ionic hydrogel according to the present invention was evaluated, and the results are shown in Fig. 1f. The weight change of the hydrogel over time was monitored at a relative humidity (RH) of 20%. The organic ionic hydrogel showed a rapid decrease in initial water content upon one day of exposure, but due to strong hydrogen bonding interactions between glycerol and adjacent water molecules, a constant water content was maintained even after seven days. Conversely, the conventional ionic hydrogel without glycerol showed rapid water evaporation, causing a rapid decrease in water content that reached nearly 0% within six hours of exposure (Fig. 1f). After seven days of exposure, the ionic hydrogel became brittle due to a significant decrease in size caused by water loss, whereas the organic ionic hydrogel exhibited initial mechanical flexibility. Furthermore, the organic ionic hydrogel of MOHF according to the present invention easily adhered to various materials such as plastics, glass, metals, rubber, wood, and fabrics due to its excellent water retention capacity. As can be seen in the photograph in Fig. 1g, MOHF exhibited excellent mechanical resilience and was susceptible to various mechanical deformations such as stretching, compression, bending, and torsion. Detailed information on the mechanical properties of MOHF is provided in Figs. 1h and 1i. The stress-strain curve of MOHF in the tensile state shows a maximum tensile stress of 173 kPa at a strain of 32%. Since the organic ionic hydrogel of MOHF is strongly bonded to the PVA / MXene-melamine foam through hydrogen bonding, the tensile stress of MOHF is higher than that of both the PVA / MXene-melamine foam and the melamine foam. In the compression test, MOHF showed a maximum stress of 2.1 MPa at a strain of 95% and demonstrated excellent resilience with nearly the same stress-strain hysteresis loop even after 30 compression / decompression cycles.

[0039] - MOHF's MEG performance

[0040] FIG. 2 shows the electrical performance of an MEG-MOHF manufactured according to an embodiment of the present invention. Specifically, in FIG. 2, (a) is a schematic diagram showing the device architecture of the MEG-MOHF. (b) the open-circuit voltage (V) of the MEG-MOHF under ambient conditions (@20% RH, 21°C). OC ) and short-circuit current (I SC ) is. (c) V of the MEG-MOHF device for various concentrations of PVA OC and I SC (d) V under various RH conditions. OC and I S (e) Output voltage of the MEG-MOHF as a function of temperature. (f) Continuous V of the MEG-MOHF over time in an open ambient environment while simultaneously recording ambient relative humidity (blue curve) and temperature (red curve). OC This is the output (black curve). (g) V of MEG-MOHF according to an external load of 10Ω to 10MΩ at 20% RH OC and J SC is. (h) V according to (g) OC and J SC It is the power density calculated from the measured values.

[0041] As schematically shown in Fig. 2a, an MOHF was placed on a silver paste-coated glass substrate, and a silver paste-coated polyethylene terephthalate (PET) substrate was inserted into the middle section of a PVA / MXene-melamine foam of the MOHF not covered by an organic ion hydrogel to develop an MEG equipped with MOHF (MEG-MOHF). The electrical performance of the MEG-MOHF was evaluated, and the results are shown in Fig. 2b. Under ambient conditions of low relative humidity (RH 20%), the MEG-MOHF maintained a stable V of approximately 300 mV for 30 minutes. OC and short-circuit current (I) in the range of approximately 1800 to 100μA SC It showed ). Stable V OC and high I SCThe advancement is due to the excellent moisture gradient occurring from bottom to top of the MOHF resulting from its asymmetric moisture absorption characteristics. On the other hand, MEG devices with symmetric moisture absorption structures, such as silver / PVA / MXene-melamine foam / silver or silver / organic ion hydrogel / silver, exhibit a negligible moisture gradient, resulting in noticeable V OC or I SC It hardly appeared.

[0042] Figure 2c shows the electrical performance of MEG-MOHF according to PVA concentration. When PVA at a low concentration (0.1 wt%) was coated on MXene / melamine foam, the resulting MEG-MOHF exhibited a V of approximately 300 mV. OC and a maximum I of approximately 1600μA SC It produced. However, when the PVA concentration was increased to 1.0 wt%, the maximum I SC It was observed that it decreased significantly to approximately 34.6 μA. This I SC The significant decrease may be due to the electrical insulation properties of PVA, which hinder charge transfer from the conductive MXene to the external electrode. However, it should be noted that PVA coating is essential because, in the absence of PVA treatment, the movement of water required to induce an ionic potential in MOHF is insufficient, causing the generated voltage to gradually decrease over time. Therefore, for subsequent experiments, an optimal PVA concentration of 0.1 wt% was selected.

[0043] To evaluate the effects of various environmental conditions, first, the electrical performance of the MEG-MOHF was measured for 30 minutes over a wide RH range of 20 to 90%, and the results are shown in Fig. 2d. At 20% RH, after 30 minutes of operation, the MEG-MOHF exhibited a V of approximately 285 mV and 124 μA, respectively. OC Wow I SC It represented. As RH increased, V OCA slight decrease was observed, but this decrease was negligible. On the other hand, the device's I after 30 minutes of operation SC increased slightly with RH, exhibiting values ​​of approximately 183, 198, 221, and 245 μA at 40, 60, 80, and 90%, respectively. In the initial state, a moisture and ion gradient occurred from bottom to top due to the organic ion hydrogel partially coated on MOHF. As RH increased, both moisture absorption and ion dissociation enhanced, leading to a large influx of ions into the uncoated area, causing the ion gradient to gradually decrease. V according to RH OC Wow I SC The decrease and increase of are each presumed to be due to the decrease in the ion gradient according to RH.

[0044] Second, as shown in FIG. 2e, the output V of the MEG-MOHF in the temperature range of -20 to 60°C OC ...was investigated. The highest V was approximately 300mV at 20°C. OC ...was obtained. Due to the excellent antifreeze ability of the glycerol and ionic salts in the organic ionic hydrogel, water can flow into the PVA / MXene layer of MOHF at temperatures below the freezing point of water, but the ion mobility within MOHF decreased. This decrease in mobility led to a decrease in the ion gradient, V OC It reduced. As the temperature increases, the enhanced ion mobility causes ions to diffuse easily to the upper electrode, causing the ion gradient to decrease with temperature, and consequently V OC ...was reduced. Therefore, balanced water molecule absorption and ion transport at an appropriate temperature are important for obtaining a stable electrical output in MEG-MOHF. A single MEG-MOHF according to the present invention provides a stable V up to 310 mV throughout the day under an open ambient environment with slight fluctuations in humidity (23 to 30%) and temperature (17 to 20°C). OCIt can provide (Fig. 2f). Stable V of MEG-MOHF due to the long-lasting ion gradient within MOHF. OC This was further verified through COMSOL simulation. As shown in Fig. 2g, V as a function of external loads ranging from 10Ω to 10MΩ. OC and J SC The power density of the MEG-MOHF was obtained by measuring. As resistance increases, V OC While increased significantly, output J SC It decreased. 9.15μW cm at 50kΩ -2 The maximum power density was obtained (Fig. 2h).

[0045] - Operating principle of MEG-MOHF

[0046] FIG. 3 illustrates the operating mechanism of MEG-MOHF prepared according to an embodiment of the present invention. Specifically, in FIG. 3, (a) is a schematic diagram of ion movement across a PVA / MXene layer facilitated by capillary action; (b) Kelvin probe force microscopy (KPFM) images of the top layer of MEG-MOHF before and after power generation and (c) surface potential distribution; (d) energy dispersive X-ray spectroscopy (EDS) mapping of the cross-section of MEG-MOHF before and after continuous power generation. In (e) to (g), the open-circuit voltage (V) of the MEG-MOHF device according to (e) MXene concentration, (f) KCl concentration, and (g) various salt ions. OC ) and short-circuit current (I SC This is an analysis of power generation performance parameters including ). (h) Measured I SC This is a comparison of the hydration radius of the ion.

[0047] The detailed mechanism of electrogeneration in MEG-MOHF is schematically illustrated in Fig. 3a. The PVA / MXene layer of MOHF contains various functional groups, such as oxygen (-O), hydroxyl (-OH), and fluorine (-F), making the MOHF surface hydrophilic with a negative zeta potential. When water penetrates the thinly coated PVA film and passes through the nano-sized MXene channels, the MXene channels become negatively charged due to water hydrolysis. The negatively charged MXene nanochannels [interact with] positively charged ions (H3O2) in the MOHF organic ionic hydrogel + and K + While allowing the passage of ) negatively charged ions (OH - and Cl - The movement of ) is hindered. This preferential cation transport promotes charge separation, generating not only an electric potential difference but also a diffusion current between the bottom and top electrodes. When an external circuit is connected, the internally generated drift current, which balances the drift current within the MOHF, is reduced. Therefore, the residual diffusion current is balanced through the external circuit, and a drift current is generated through the external resistance.

[0048] The proposed mechanism was verified using Kelvin probe force microscopy (KPFM), and the results are shown in Figs. 3b and 3c. By scanning the surface of the top electrode portion of the MEG-MOHF, it was observed that the potential of the MEG-MOHF increased from 398 mV to 563 mV after power generation (Figs. 3b and 3c). This result suggests that positive charge carriers were preferentially accumulated through the coated PVA / MXene layer. Furthermore, as can be seen in Fig. 3d, in the energy dispersive X-ray spectroscopy (EDS) image of the cross-sectional MOHF, K +It can be observed that ions traveled along the PVA / MXene layers from the bottom to the top of the sample. As the volume of PVA / MXene not coated with the organic ion hydrogel increases, the ion gradient of the expanded PVA / MXene is strengthened, V OC increased slightly. On the other hand, due to the increase in internal resistance, I SC It decreased, which demonstrated the proposed mechanism based on preferential ion separation and transport in PVA / MXene layers.

[0049] In addition, we investigated how various factors affect the electrical properties of MEG-MOHF. Figure 3e shows the V of MEG-MOHF as a function of MXene concentration. OC Wow I SC It shows that as the MXene concentration increases, V OC Wow I SC All were significantly improved, 1.0 mg ml -1 V up to 305mV at concentration OC and I of ~1700μA SC It reached 1.0 mg ml -1 No significant changes were observed above the concentration. The improved performance is due to the increased specific surface area and enhanced electrical conductivity of MOHF as the MXene concentration increased. Additionally, the KCl concentration [varies from] the V of MEG-MOHF OC and I SC The effect on was investigated, and the results are shown in Fig. 3f. As a result of using a KCl-free organic hydrogel, V OC Wow I SC were found to be approximately 31mV and 0.6nA, respectively. V OC Wow I SC Significant improvements were made in all aspects, which supports the inventor's claims regarding salt-related electric generation.

[0050] In addition, the effects of various desiccant chlorides on the energy harvesting performance of MEG-MOHF were investigated, and the results are shown in Figures 3g and 3h. Four commonly used desiccant chlorides, namely NaCl, KCl, CaCl2, and MgCl2, were investigated at an equivalent concentration of 1.0 M. Salts with monovalent ions were compared to salts with divalent ions... SC was high, but V OC was low. This behavior may be due to differences in ion charge density and mobility. Since divalent ions have a high charge density, the potential difference of the MOHF increases, leading to an increase in output voltage. On the other hand, monovalent ions have a small hydrated radius, so they face less obstruction when moving across the PVA / MXene layer, allowing them to generate a higher current than divalent ions. Therefore, as shown in Fig. 3h, K, which has the smallest hydrated radius + The highest I ion SC It represents.

[0051] - Mechanically deformable MEG-MOHF

[0052] FIG. 4 shows the mechanical properties of an MEG-MOHF manufactured according to an embodiment of the present invention. Specifically, in FIG. 4, the open-circuit voltage (V) of the MEG-MOHF device according to various mechanical operations such as (a) stretching, (b) compression, (c) twisting, and (d) bending. OC ) and short-circuit current (I SC (e) Schematic diagram of the resistance network of the MOHF and its equivalent circuit diagram. (f) Various shape variations appearing in large MEG-MOHF. (g) Measured output voltage of the MEG-MOHF under extreme pressure conditions.

[0053] The MEG performance of mechanically deformable MOHF was explicitly investigated, and the results are shown in Fig. 4. First, V under stretching, pressing, twisting, and bending conditionsOC Wow I SC Measurements were taken, and the results are shown in Figs. 4a, 4b, 4c, and 4d, respectively. For electrical measurements under stretching, torsion, and bending conditions, a 40 × 10 × 4 mm 3 While the volume of MEG-MOHF was examined, the volume of the compressed sample was 20 × 20 × 10 mm 3 It was. In all cases, silver paste-coated PET electrodes were used. Additionally, over time I SC Considering that it decreases, I at a value of approximately 20μA SC Measurements were performed after sufficient stabilization (see Fig. 2b). As a result, in all samples, V remained stable even after various deformations. OC The values ​​were found to remain almost unchanged. This result suggests that the reduction in pore size of MOHF due to compression, stretching, twisting, and bending hardly alters the ion gradient within MOHF.

[0054] Conversely, when MEG-MOHF is deformed by various mechanical forces, I SC increased. SC The increase can be explained by the resistance network model of the conductive framework, as schematically illustrated in Fig. 4e. The electrical resistance (R) of the composite material is the resistance (R) of both outer layers. O1 and R O2 ) and the resistance of the central layer (R CIt can be expressed as the sum of ). Since the layer coated with the organic ion hydrogel exhibited a higher compressive modulus than the uncoated region, it was assumed that mechanical deformation primarily occurred in the uncoated portion. In the low strain regimes, as can be seen in the middle of Fig. 4e, the cells of the upper outer layer flattened first, forming conductive connections within those layers. The electrical resistance of the upper outer layer is the initial resistance R O1 and resistance R associated with the new conductive path N It was included in parallel. Meanwhile, the resistance of the central layer (R C ) and the resistance of another outer layer (R O2 ) did not change. In this situation, the total resistance is R = R O1 / / R N + R C + R O2 It can be calculated as follows. As the strain increases, both the upper outer cell and the central cell flatten out, forming many conductive connections. In this case, the total resistance is R = R C / / R N + R O2 It can be expressed as. The formation of a conductive path due to mechanical deformation is I SC I think it is the cause of the increase.

[0055] Additional experiments were conducted on the MEG-MOHF to evaluate energy generation under more severe deformation. The excellent flexibility and durability of the MEG-MOHF were confirmed through knotting, rolling, and folding experiments with large pieces, and as shown in Fig. 4f, the MEG-MOHF simultaneously produced a stable V of ~280 mV. OC It maintained. In the case of the extreme compression test, when driving a vehicle over MEG-MOHF and the MEG-MOHF is compressed under the moving tires of a commercial vehicle, V OCThe value was monitored; the result is shown in Fig. 4g. V generated in the stable state (Step 1 in Fig. 4g) OC V suddenly decreased to ~25mV when the vehicle passed over the MEG-MOHF (Step 2 of Fig. 4g). However, after the vehicle passed, V of the MEG-MOHF OC It recovered up to approximately 200mV, demonstrating the excellent resilience of MEG-MOHF to mechanical deformation and its moisture energy generation ability.

[0056] - MOHF TENG performance

[0057] FIG. 5 shows the electrical performance of a TENG-MOHF manufactured according to an embodiment of the present invention. Specifically, in FIG. 5, (a) is a schematic diagram illustrating the device architecture of the TENG-MOHF. (b) the operating principle of the TENG-MOHF based on the contact-disconnection mode. (c) V of the TENG-MOHF device as a function of RH. OC and (d) I SC (e) V of a TENG-MOHF device in which the compression pressure varies from 7.8 to 28.3 kPa, and (f) the vertical operating frequency varies from 0.5 to 10.0 Hz. OC and I SC (g) V generated from the TENG-MOHF attached to the shoe during walking, running, and jumping OC (h) Results of the stability and durability of TENG-MOHF for over 30,000 cycles. (i) V of TENG according to external loads of 30kΩ to 700MΩ at 20% RH. OC and J SC is. (j) V according to (i) OC and J SC It is the power density calculated from the measurement.

[0058] MOHF, which possesses excellent mechanical elasticity, functions as an excellent triboelectric layer in TENGs that harvest mechanical energy through repetitive vertical contact in addition to harvesting energy from moisture. As schematically illustrated in Fig. 5a, a TENG using MOHF (TENG-MOHF) was implemented by establishing direct contact between an MOHF incorporating a silver-coated PET substrate and a perfluoroalkoxy (PFA) film attached to a Cu electrode. The operating principle of the TENG-MOHF in contact-separation mode is schematically illustrated in Fig. 5b. When the PFA film comes into contact with the MOHF, triboelectricity is generated, creating electrostatic charges with opposite signs on the two triboelectric surfaces due to the difference in their work functions. The PFA film becomes negatively charged because of its high affinity for electrons. Meanwhile, the surface of the MOHF becomes positively charged, inducing a potential difference between the two electrodes. When the PFA film begins to separate from the MOHF, electrons flow from the Cu electrode to the silver electrode through an external circuit to maintain charge equilibrium. This flow of electrons generates an electrical output current and continues until all negative charges accumulated on the PFA surface are completely canceled out. Subsequently, when the PFA film approaches the MOHF again, the direction of electron movement is reversed from the silver electrode back to the Cu electrode to maintain charge balance, generating an electrical output signal of opposite polarity (Fig. 5b).

[0059] The triboelectric output voltage and current of the TENG-MOHF were investigated as a function of relative humidity, and the results are presented in Figs. 5c and 5d, respectively. The humidity-dependent triboelectric performance of the device according to the present invention is important for developing a complementary energy generator (complementary MEG-TENG-MOHF) that integrates MEG and TENG with MOHF, as will be shown later. Prior to the measurement, the surface area of ​​the PFA film was adjusted to 2×2 cm² to match the top surface area of ​​the MOHF. At 20% RH, the TENG-MOHF has a maximum V of 80 V. OCand 3.5μA of I SC It represented. These values ​​surpassed the electrical performance of TENGs using melamine foam as is or melamine foam coated with an MXene film. However, as RH increased, V OC Wow I SC A gradual decrease was observed in all cases. At 80% RH, V of 30V OC and 0.65μA of I SC Since moisture in the air can induce an electric current between charged surfaces, static electricity generated in the TENG-MOHF at high humidity was easily dispersed, leading to a reduction in power output consistent with previous results. From these results, it is expected that the complementary MEG-TENG-MOHF can generate high power under low humidity conditions, where most MEGs exhibit low harvesting performance due to a lack of moisture.

[0060] Due to the excellent mechanical flexibility and elasticity of the MOHF, the TENG-MOHF can harvest energy under various compression conditions, and the results are shown in Fig. 5e. As the compression pressure increases from 7.8 to 28.3 kPa, V of the TENG-MOHF OC It increased from 50 to 110V and I SC increased from 2.5 to 7.6 μA. With various pressures applied, the compression ratio of the device increased from 10 to 52%. In addition, as can be seen in Fig. 5f, as the operating frequency of the TENG-MOHF increased from 0.5 to 10 Hz, V OC Wow I SCSignificant increases were observed in all cases. The improvement in device performance at high frequencies is due to the low dispersion of induced charges in the PFA film and MOHF. Figure 5g demonstrates the mechanical robustness of the MOHF, which can harvest triboelectric energy generated during various human movements such as walking, jumping, and running, from the TENG-MOHF patched onto the shoe. As shown in Figure 5h, the mechanical durability of the TENG-MOHF was confirmed once again by maintaining stable TENG performance even after more than 30,000 continuous triboelectric contacts. As indicated in Figure 5i, V across various external loads ranging from 30kΩ to 70MΩ OC and J SC The power density of the TENG-MOHF was measured by measuring [the value]. The result was approximately 30.1 μW cm⁻¹ at 30 MΩ. -2 It shows that the maximum power density can be achieved (Fig. 5j).

[0061] - Modifiable Complementary MEG-TENG-MOHF

[0062] FIG. 6 illustrates the electrical performance of a complementary MEG-TENG-MOHF manufactured according to an embodiment of the present invention. Specifically, in FIG. 6, (a) is a schematic diagram showing the device architecture of the complementary MEG-TENG-MOHF. (b) is a circuit diagram and photograph of the complementary MEG-TENG-MOHF used to supply power to a load device. (c) V for the MEG-MOHF, TENG-MOHF, and complementary MEG-TENG-MOHF. OC and (d) I SC This is a comparison. (e) V of the complementary MEG-TENG-MOHF with respect to load resistance at 20% RH OC and J SC (f) Power density calculated from the results of (e). (g) Radial graph of voltage, current, power density, tensile strength, and compressive strength of the complementary MEG-TENG-MOHF. (h) Capacitor charging characteristics of each energy generator using a 4.7μF capacitor.

[0063] Utilizing the function of the MOHF to harvest energy from ambient moisture and tribo-contact force, a complementary MEG-TENG-MOHF was developed, in which both MEG and TENG are integrated into a single device platform with a shared MOHF, as schematically illustrated in Fig. 6a. A silver-coated PET electrode was inserted into the center of the PVA / MXene-melamine foam within the MOHF. The inserted electrode acted as a mutual electrode, functioning as the top electrode of the MEG-MOHF and the bottom electrode of the TENG-MOHF. As schematically shown in Fig. 6b, the Cu / PFA tribo-contact electrode (top electrode of the TENG-MOHF) and the inserted electrode (bottom electrode of the TENG-MOHF) were connected to two terminals of a bridge rectifier to convert alternating current (AC) to direct current (DC). The remaining two terminals of the bridge rectifier were connected to the top and bottom electrodes of the MEG-MOHF (Fig. 6b). In addition, a diode was connected to the bottom electrode of the MEG-MOHF to suppress electron leakage during energy generation. As shown in the photograph in Fig. 6b, a complementary MEG-TENG-MOHF was successfully fabricated with the designed circuit.

[0064] The electrical performance of the complementary MEG-TENG-MOHF was evaluated at 20% RH, and the results are shown in Figures 6c and 6d. The complementary MEG-TENG-MOHF exhibited V of approximately 55 V and 100 μA, respectively. OC Wow I SC It exhibited, and intermittent peaks occurred at regular intervals. As can be seen from the electrical performance of MEG-MOHF and TENG-MOHF obtained simultaneously for comparison, the high V of the complementary MEG-TENG-MOHF OC Wow I SCThis can be attributed to the high output voltage of the TENG-MOHF and the high current of the MEG-MOHF, respectively. While bright light was emitted from two commercial LEDs connected in series with the complementary MEG-TENG-MOHF, no light emission or somewhat weak light emission was observed from the MEG-MOHF and TENG-MOHF. The power density of the complementary MEG-TENG-MOHF was evaluated from the output voltage and current densities as a function of the device's load resistance, and the results are shown in Figures 6g and 6f. Over a wide range of load resistances from 1 kΩ to 70 MΩ, the average power density of the complementary MEG-TENG-MOHF was approximately 33.6 μW cm⁻¹. -2 It was confirmed that the maximum power density achieved was approximately 83 μW cm⁻¹ at 700 kΩ, as shown in Fig. 6f. -2 was.

[0065] It is also worth noting that the maximum power density and mechanical performance of the complementary device are superior to recent MEG performance (Fig. 6g). The power density is similar to that obtained from solar and other MEG hybrid devices. Furthermore, the complementary MEG-TENG-MOHF, with its excellent mechanical flexibility and resilience, is suitable for applications requiring large mechanical forces, as will be explained later.

[0066] To further investigate the synergistic effect of the energy storage functions of MEG-MOHF and TENG in the complementary MEG-TENG-MOHF device, a charging experiment was performed using a 4.7μF capacitor, and the results are shown in Fig. 6h. In the capacitor charging curve of the complementary device, the initial voltage of the capacitor rapidly reached approximately 0.25V within 1-2 seconds. Subsequently, the voltage increased almost linearly over time, reaching approximately 0.9V after 80 seconds. The charging curve of the MEG-MOHF showed that the charging voltage rapidly increased to 0.25V within a few seconds. The charging of the TENG-MOHF occurred almost linearly over time, reaching a charging voltage of approximately 0.8V after 80 seconds (Fig. 6h). The high capacitor charging performance of the complementary MEG-TENG-MOHF was explained by the rapid increase in the initial voltage of the capacitor, which is a result of the DC characteristics of the MEG-MOHF and leads to subsequent charging of the device facilitated by the TENG-MOHF part. The high charging performance of the complementary harvester was enhanced by higher-capacity capacitors. In addition, the stable charging and discharging characteristics of the complementary MEG-TENG-MOHF were also confirmed.

[0067] - Self-generating emergency exit guidance system equipped with modifiable complementary MEG-TENG-MOHF

[0068] FIG. 7 illustrates a method for manufacturing and using an emergency exit guidance system according to an embodiment of the present invention. Specifically, in FIG. 7, (a) multiple MEG-MOHF units are connected in series and parallel to V OC and I SC (b) A schematic diagram and photograph of a 3 x 3 array of complementary MEG-TENG-MOHF. Multiple MOHFs are connected in series, and PFA films are connected in parallel. (c) A schematic diagram and (d) experimental results showing the utilization of a complementary MEG-TENG-MOHF array in an emergency exit guidance system.

[0069] For practical applications suitable for the deformable complementary MEG-TENG-MOHF, it is necessary to expand the power output of the system. Figure 7a shows how various commercial electronic products can be operated by connecting multiple MEG-TENG-MOHF units (up to 8 units) in series or parallel to amplify the output voltage and current, respectively, in MEG mode. To utilize the mechanical resilience of the complementary MEG-TENG-MOHF, which can withstand human weight, a new self-generating emergency exit guidance system is proposed that can visually guide people to emergency exits when needed. As can be seen in the schematic diagram and photograph in Figure 7b, a 3 x 3 complementary MEG-TENG-MOHF array was fabricated on an acrylic substrate using a Cu / PFA film separated from the MOHF array by four springs. In the array system, nine MEG-MOHF units are connected in series to generate continuous moisture-driven DC output power, and TENG-MOHF units are connected in parallel to generate high-power AC output from transient human walking motion.

[0070] Figure 7c illustrates an implementation scenario of a self-generating emergency exit guidance system. Under normal circumstances, LED signs near the exit are always illuminated due to the continuous DC power of the MEG-MOHF array; however, due to the relatively low output power of the MEG, these signs are not sufficiently bright. In emergency situations, such as a fire where indoor lighting is limited, the MEG-driven lights serve as initial guides toward the emergency exit, allowing nearby people to follow the lights to escape. When people follow the sign lights and step onto the array system located near the emergency exit while evacuating, the TENG-MOHF array begins to generate additional output power through repeated contact of the Cu / PFA plates with the MOHF, as schematically shown in Figure 7c, providing additional visual guidance toward the exit. As more people move toward the exit, more power is generated by the array system, enabling clearer exit guidance, thus allowing for the development of a self-generating and self-sustaining system for effective evacuation.

[0071] A proof-of-the-concept of a self-generating emergency exit guidance system was developed using a complementary MEG-TENG-MOHF array, and the results are shown in Fig. 7d. A single red LED is connected to the circuit of the array of MEG-MOHF units, and ten blue LEDs arranged in an arrow shape are connected to the circuit of the array of TENG-MOHF units. Under bright conditions, the red light emitted from the MEG-MOHF array is barely visible, as shown in the left image of Fig. 7d; however, in a simulated emergency situation where ambient lighting is turned off, it becomes easily visible. Subsequently, when the array system is repeatedly stepped on, the arrow-shaped blue LEDs are turned on by the output power generated by the TENG-MOHF array, as shown in the right photo of Fig. 7d, and the perception of light is greatly improved.

[0072] [Experimental Example]

[0073] According to one embodiment of the present invention, the details of an actual experiment are introduced below.

[0074] (1) Materials

[0075] The melamine foam used is a product commercially available in Korea. Acrylamide (≥99%), N,N'-Methylenenebis(acrylamide) (MBAA, 98%), ammonium persulfate (APS, 98%), glycerol (≥99.5%), KCl, NaCl, CaCl2, MgCl2, and poly(vinyl alcohol) (PVA, M w = 30,000~70,000) was purchased from Sigma-Aldrich Korea. MXene suspension (10 mg ml -1 ) was purchased from XinXi Technology Co. Ltd. (Foshan, China). Deionized water (DI) (18.3 MΩcm) was prepared using a reverse osmosis water purification system (Human Corporation, Korea). Perfluoroalkoxyalkanes (PFA) with a thickness of 25 μm were purchased from Alphafron (Korea).

[0076] (2) Preparation of melamine foam coated with MXene and PVA (PVA / MXene-melamine foam)

[0077] A dip coating method was used for the manufacture of PVA / MXene-melamine foam. Initially, the melamine foam was 20×20×10 mm 3 It was cut into cubes of a certain size. Then, the foam was soaked in deionized water (DI) (1.0 mg ml -1 After immersing the foam in an MXene solution diluted in ) for 10 minutes, pressure was applied several times to ensure the solution permeated the foam well. The wet melamine foam was dried in an oven at 60°C overnight. Subsequently, the dried sample was immersed in a PVA solution (0.1 wt%) for 10 minutes. After completely drying in an oven at 60°C overnight, the final product, PVA / MXene-melamine foam, was obtained.

[0078] (3) Preparation of MXene / organic ionic hydrogel foam (MOHF)

[0079] Acrylamide monomer (1.54 g), MBAA crosslinking agent (0.006 g), and APS initiator (0.016 g) were dissolved in a solvent containing a mixture of 10 ml of glycerol and deionized water (DI) in a 3:2 volume ratio. The solution was magnetically stirred for 30 minutes, and KCl was added to the solution to obtain various concentrations. Then, 1 ml of the solution was poured into a custom-designed mold, and the prepared PVA / MXene-melamine foam was placed on top to allow the organic ion hydrogel solution to be injected downward through capillary action. Finally, the solution was heat-treated on a hot plate at 85°C for 10 minutes to allow the viscous solution to gradually polymerize and form MOHF.

[0080] (4) Characterization and Measurement

[0081] The surface morphology and crystallinity of melamine foam and PVA / MXene-melamine foam were examined using field emission scanning electron microscopy (FE-SEM) (JEOL, JSM-7001F) and high-resolution X-ray diffraction (HR-XRD, Rigaku, SmartLab) at an acceleration voltage of 10.0 kV. The MXene and PVA coating layers of the melamine foam were confirmed via transmission electron microscopy (TEM, JEOL, JEM-ARM 200F). The chemical composition of PVA / MXene-melamine foam and its components was studied using X-ray photoelectron spectroscopy (XPS, Thermo UK, K-alpha). The zeta potential of PVA / MXene-melamine foam was measured using a zeta potential analyzer (Otsuka Electronics, ELS-1000ZS). K over time in MOHF using Finite Element Analysis (FEA) software (COMSOL, Inc., COMSOL Multiphysics 5.6) + Numerical simulations were performed on the concentration distribution. Mechanical properties were evaluated on a general-purpose tester (UTM, Instron, Instron 3366) equipped with a 50N load cell. 40 × 10 × 4 mm 310 mm min with a strip-shaped sample of size with a gauge length of 20 mm between clamps -1 It was stretched axially at a loading rate. In addition, for the compression test, 20 × 20 × 10 mm 3 Sample size 10 mm min -1 It was compressed vertically at a loading rate. V of MEG-MOHF, TENG-MOHF, and complementary MEG-TENG-MOHF was measured using a commercial multimeter, a Keithley 6514 electrometer, and a Keithley 6485 picoammeter. OC and I SC RH in the controlled environment was maintained in a custom-made acrylic humidity chamber. To establish a temperature range from -20°C to 60°C, a refrigerator and a hot plate were used in the experimental setup. Energy dispersive spectroscopy (EDS, JEOL, JSM-7610F-Plus) and Kelvin probe force microscopy (KPFM) characterization (Park Systems, NX-10) were used to analyze the migration of ions generated in MEG-MOHF and changes in surface potential.

Claims

Claim 1 An organic-ionic hydrogel foam comprising MXene and having a three-dimensional skeletal structure; comprising an organo-ionic hydrogel coating a portion of the MXene foam, wherein a dry region not coated by the organo-ionic hydrogel is positioned on a wet region coated by the organo-ionic hydrogel, and wherein the MXene foam is a melamine foam with a three-dimensional structure having MXene flakes attached thereto, and subsequently a poly(vinyl alcohol) (PVA) film is coated on the melamine foam with the attached MXene flakes. Claim 2 In claim 1, the MXene foam is an organic ionic hydrogel foam in which MXene flakes of a two-dimensional structure are attached to a melamine foam of a three-dimensional structure. Claim 3 An organic ionic hydrogel foam according to claim 1, wherein the organic ionic hydrogel is based on polyacrylamide (PAM) containing glycerol and an ionic salt. Claim 4 A method for manufacturing an organo-ionic hydrogel foam, comprising the steps of: manufacturing a MXene foam having a three-dimensional skeletal structure containing MXene; coating a portion of the MXene foam with an organo-ionic hydrogel, wherein the step of manufacturing the MXene foam includes the step of coating MXene flakes on the surface of a melamine foam; and the step of coating a poly(vinyl alcohol) (PVA) film on the melamine foam coated with MXene flakes. Claim 5 A method for manufacturing an organic ionic hydrogel foam according to claim 4, wherein the step of manufacturing the MXene foam includes the step of coating MXene flakes on the surface of a melamine foam. Claim 6 A method for manufacturing an organic ionic hydrogel foam according to claim 4, wherein the step of coating with the organic ionic hydrogel comprises the step of partially coating the MXene foam with an organic ionic hydrogel based on polyacrylamide containing glycerol and an ionic salt. Claim 7 A moisture-inducing generator comprising: an organic ionic hydrogel foam according to claim 1; a first conductive substrate disposed below the organic ionic hydrogel foam; and a second conductive substrate inserted into the drying region of the organic ionic hydrogel foam. Claim 8 A triboelectric generator comprising: an organic ionic hydrogel foam according to claim 1; a third conductive substrate disposed on top of the organic ionic hydrogel foam; and a fourth conductive substrate inserted into the drying region of the organic ionic hydrogel foam. Claim 9 A moisture-induced and triboelectric generator comprising: an organic ionic hydrogel foam according to claim 1; a fifth conductive substrate disposed below the organic ionic hydrogel foam; a sixth conductive substrate disposed above the organic ionic hydrogel foam; and a seventh conductive substrate inserted into the drying region of the organic ionic hydrogel foam, wherein the fifth conductive substrate, the organic ionic hydrogel foam, and the seventh conductive substrate generate direct current (DC) power by moisture-induced power generation, and the sixth conductive substrate, the organic ionic hydrogel foam, and the seventh conductive substrate generate alternating current (AC) power by triboelectric power generation. Claim 10 An emergency exit guidance system using a moisture induction and triboelectric generator according to claim 9, wherein the direct current (DC) power generated by the moisture induction generation is always switched on, and the alternating current (AC) power generated by the triboelectric generation is generated by the steps of people evacuating in an emergency situation.

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