Energy harvesting system based on inverse electrowetting of a dielectric

Abstract

Energy harvesting system based on inverse electrowetting on a dielectric, wherein the energy harvesting system comprises: a dielectric material layer (100) formed with a dielectric material in a plate shape and having an upper end and a lower end, wherein the upper end is arranged higher than the lower end in the direction of gravity, and is configured to allow a liquid droplet (W1, W2) to flow from the upper end to the lower end along an upper surface of the dielectric material layer (100), and wherein the upper surface of the dielectric material layer (100) is configured to generate a dielectric polarization in the dielectric material layer (100) by flowing the liquid droplet (W1, W2), and is configured to continuously vary a flow rate (F1, F2) of the liquid droplet (W1, W2) between the upper end and the lower end of the dielectric material layer (100), and an electrode layer comprising a plurality of electrodes (200) coupled to a lower surface of the dielectric material layer (100), wherein electrodes (200) from the plurality of electrodes (200) are arranged such that they are spaced apart from each other in a direction from the upper end of the dielectric material layer (100) to the lower end of the same and are polarized by the dielectric polarization of the dielectric material layer (100).

Description

Area

[0001] The present disclosure relates to an energy generation system based on inverse electrowetting of a dielectric, which converts mechanical energy into electrical energy using the movement of a liquid droplet. background

[0002] The statements in this section merely provide background information relating to the present disclosure and do not necessarily represent the state of the art.

[0003] Energy harvesting technology refers to the collection and reuse of light, thermal, kinetic, and similar energy that would otherwise go unused or unused in daily life. Currently, its use is too cumbersome and the output is low, which is why its practical application has not been actively pursued. However, recent developments in Internet of Things (IoT) technology and widespread adoption have created a need for energy harvesting technologies capable of continuously supplying or providing power despite low output.

[0004] When a liquid droplet, such as water, which is a polar material, comes into contact with a dielectric material, such as a polymer or similar, the water develops positive charges at the interface between the water and the dielectric material, and the dielectric material forms an electrical double layer, which carries negative charges. A surface of the dielectric material is negatively charged, and simultaneously, electrical polarization occurs within the dielectric material itself, so that a surface of the dielectric material in contact with an electrode becomes positively charged. Therefore, electrons move through the electrode beneath the dielectric material, resulting in an electric current.This is referred to as an inverse electrowetting phenomenon (see document: “Micro Energy Harvesting System Based on Reverse Electro Wetting On Dielectric (REWOD)”, Collected Publications of the Korean Society for Fluid Machinery, Vol. 18, No. 6, pp. 27–30, 2015).

[0005] However, as shown in Fig. Figure 1 shows that a conventional energy harvesting system based on inverse electrowetting of a dielectric exhibits a constant inclination, such that a situation in which a liquid droplet W approaches an electrode 200 and a situation in which the liquid droplet W moves away from the electrode 200 can occur simultaneously. We found that one problem is that a majority of the electrodes carry negative charges, and therefore there is no potential difference between the majority of the electrodes, so a current I0 is not generated.

[0006] Therefore, a new structure is desirable in which a net current is generated by varying the flow rate of a liquid droplet, even in the energy harvesting system based on inverse electrowetting of a dielectric.

[0007] The preceding statements serve only to provide a better understanding of the background of the present disclosure and are not intended to suggest that the present disclosure is situated within the field of prior art already known to the person skilled in the art.

[0008] JP 2016 - 153 725 A discloses a control method for a droplet transport device, wherein the droplet transport device comprises: a plate; a control electrode to which a control voltage is applied; a dielectric layer formed to cover the control electrode; and a droplet. While the control voltage is continuously reduced to one control electrode to which the control voltage is applied in order to hold the droplet on the control electrode, a control voltage is applied to another control electrode adjacent to the first control electrode to transport the droplet to the other control electrode. Contents

[0009] Accordingly, the present disclosure has been realized taking into account the preceding problems arising in the prior art, and the present disclosure is intended to propose an energy generation system based on inverse electrowetting of a dielectric, which converts mechanical energy into electrical energy using a movement of a liquid droplet easily visible from the surroundings, without a separate power supply.

[0010] According to one aspect, the present disclosure provides an energy harvesting system based on inverse electrowetting on a dielectric, wherein the energy harvesting system comprises: a dielectric material layer formed in a plate shape with or from a dielectric material and having a top end and a bottom end, and an electrode layer comprising a plurality of electrodes coupled to or provided on a bottom surface of the dielectric material layer.The upper end is positioned higher than the lower end in the direction of gravity and is configured to allow a liquid droplet to flow from the upper end to the lower end along an upper surface of the dielectric material layer. The upper surface of the dielectric material layer is configured to generate dielectric polarization within the layer as the liquid droplet flows, and to continuously vary the flow rate of the liquid droplet between the upper and lower ends of the dielectric material layer. Electrodes from the plurality of electrodes can be spaced apart from each other in a direction from the upper to the lower end of the dielectric material layer and can be polarized by the dielectric polarization of the dielectric material layer.

[0011] In one embodiment, the dielectric material layer has curved sections which are arranged between the upper end and the lower end of the dielectric material layer in order to continuously vary the flow rate of the liquid droplet.

[0012] The energy generation system can further include a cover layer formed from a hydrophobic substance in plate form and coupled to the upper surface of the dielectric material layer.

[0013] The liquid droplet can flow along an upper surface of the covering layer.

[0014] The energy generation system may also include a base substrate which is coupled to the lower surface of the dielectric material layer and / or the electrode layer.

[0015] The dielectric material layer can have: a first section which is inclined at a predetermined angle of inclination, and a second section which is inclined at an angle of inclination which is greater than the predetermined angle of inclination of the first section, wherein the first section and the second section can be arranged alternately such that the dielectric material layer is continuously bent between the upper end and the lower end of the dielectric material layer.

[0016] In another embodiment, electrodes from the plurality of electrodes can be coupled to a lower surface of the first section and a lower surface of the second section of the dielectric material layer.

[0017] An upper end and a lower end of a first electrode from the plurality of electrodes, which is coupled to the first section, can be arranged at positions aligned with an upper end and a lower end of the first section; an upper end and a lower end of a second electrode from the plurality of electrodes, which is coupled to the second section, can be arranged at positions aligned with an upper end and a lower end of the second section; and the upper ends and the lower ends of the first and second electrodes, which are coupled to the first section and the second section, can be spaced apart from each other.

[0018] The majority of electrodes can be coupled in such a way that the electrodes run over a lower surface of the first section and a lower surface of the second section at curved points of the first section and the second section.

[0019] The curved points of the first and second sections can be formed in a curved line shape.

[0020] The majority of electrodes can be coupled to a lower surface of the first section and to a lower surface of the second section of the dielectric material layer.

[0021] The majority of electrodes can be coupled in such a way that the electrodes run over a lower surface of the first section and a lower surface of the second section at curved points of the first section and the second section.

[0022] Each of the plurality of electrodes can be configured with first electrodes and second electrodes, and the first electrodes and the second electrodes can be arranged alternately on the lower surface of the dielectric material layer.

[0023] The energy harvesting system can further comprise a pair of feed devices arranged at both ends of the electrode layer to enable a current flow, wherein the first electrodes can be connected to one feed device from the pair of feed devices provided on one side of the electrode layer and the second electrodes can be connected to the other feed device from the pair of feed devices provided on the other side of the electrode layer.

[0024] Further areas of application will become apparent from the description provided here. It should be understood that the description and specific examples are provided for illustrative purposes only and are not intended to limit the scope of this disclosure. Drawings

[0025] To facilitate a better understanding of the disclosure, numerous embodiments thereof are now described, which are merely examples. Reference is made to the accompanying drawings, whereby: Fig. 1 is a representation that illustrates a concept of a conventional energy harvesting system based on inverse electrowetting on a dielectric, Fig. 2 is a representation illustrating a concept of an energy harvesting system based on inverse electrowetting on a dielectric according to an embodiment of the present disclosure, Fig. 3 is a representation illustrating an energy harvesting system based on inverse electrowetting on a dielectric according to an embodiment of the present disclosure, Fig. 4 is a representation illustrating an energy harvesting system based on inverse electrowetting on a dielectric according to a further embodiment of the present disclosure, Fig. 5 is a representation illustrating an energy harvesting system based on inverse electrowetting on a dielectric according to a further embodiment of the present disclosure, Fig. 6 is a representation illustrating an energy harvesting system based on inverse electrowetting on a dielectric according to a further embodiment of the present disclosure, and Fig. 7 is a representation illustrating an electrode layer and a support of the energy harvesting system based on inverse electrowetting on a dielectric according to a further embodiment of the present disclosure.

[0026] The drawings described herein are provided for illustrative purposes only and are not intended to limit the scope of the present disclosure in any way. Detailed description

[0027] The following description is merely exemplary and is not intended to limit the present disclosure, its application, or use. It should be understood that corresponding reference numerals in the drawings denote similar or corresponding parts and features.

[0028] Fig. Figure 1 is a representation illustrating a concept of an energy harvesting system based on inverse electrowetting on a dielectric. Fig. Figure 2 is a representation illustrating a concept of an energy harvesting system based on inverse electrowetting on a dielectric according to an embodiment of the present disclosure. Fig. Figure 3 is a representation illustrating an energy harvesting system based on inverse electrowetting on a dielectric according to an embodiment of the present disclosure. Fig. Figure 4 is a representation illustrating an energy harvesting system based on inverse electrowetting on a dielectric according to another embodiment of the present disclosure. Fig. Figure 5 is a representation illustrating an energy harvesting system based on inverse electrowetting on a dielectric according to a further embodiment of the present disclosure. Fig. Figure 6 is a representation illustrating an energy harvesting system based on inverse electrowetting on a dielectric according to another embodiment of the present disclosure. Fig. Figure 7 is a representation illustrating an electrode layer and a support of an energy harvesting system based on inverse electrowetting on a dielectric according to a further embodiment of the present disclosure.

[0029] As in the Fig. Figure 2-6 shows an energy harvesting system based on inverse electrowetting on a dielectric: a dielectric material layer 100, formed in a plate shape with a dielectric material and having an upper and a lower end, and an electrode layer having a plurality of electrodes 200. The upper end is located higher than the lower end, so that a liquid droplet W, W1, W2 flows from the upper end to the lower end along an upper surface of the dielectric material layer 100, thereby generating a dielectric polarization in the upper surface of the dielectric material layer through a flux F, F1, F2 of the liquid droplet W, W1, W2.The dielectric material layer has successive curved sections 150 extending from the upper end to the lower end to continuously vary or change the flow rate of the liquid droplet W, W1, W2. The majority of electrodes 200 are coupled to a lower surface of the dielectric material layer 100, and electrodes from the majority of electrodes 200 are arranged such that they are spaced apart from each other in a direction from the upper end of the dielectric material layer 100 to its lower end and are polarized by the dielectric polarization of the dielectric material layer 100.As described above, the liquid droplet W, W1, W2 is allowed to flow on an upper surface of the energy harvesting system based on inverse electrowetting on a dielectric such that mechanical energy is converted into electrical energy by the action of gravity. In this case, a wire is connected between the electrodes 200 to induce electron movement in such a way that a current can be generated and used.

[0030] Even in the prior art, an energy harvesting system based on inverse electrowetting on a dielectric converts mechanical energy into electrical energy using a liquid droplet flow. However, the conventional energy harvesting system based on inverse electrowetting on a dielectric exhibits, as in Fig. As shown in Figure 1, the dielectric material exhibits a constant inclination, such that a situation in which the liquid droplet W approaches the electrode 200 and a situation in which the liquid droplet W moves away from the electrode 200 can occur simultaneously. Therefore, a problem arises in that a plurality of electrodes 200 have negative charges, and consequently, there is no potential difference between the plurality of electrodes 200, so that the current I0 is not generated. To solve such a problem, the dielectric material layer 100 of the present disclosure has successive curved sections 150, which extend from the upper end to the lower end such that a flow rate of the liquid droplet W, W1, W2 is continuously varied. As shown in Figure 1, the dielectric material layer 100 has successive curved sections 150 extending from the upper end to the lower end such that the flow rate of the liquid droplet W, W1, W2 is continuously varied. Fig. Figure 2 shows a rate F1 at which the liquid droplet W, W1, W2 approaches each of the plurality of electrodes 200, different from a rate F2 at which the liquid droplet W, W1, W2 moves away from each of the plurality of electrodes 200 on the upper surface of the dielectric material layer 100, and therefore the liquid droplet W, W1, W2 remains longer at a position on the dielectric material layer 100 which has a small angle of inclination, so that a probability of a potential difference between the plurality of electrodes 200 increases and therefore a current I1 is generated.

[0031] This means that, as in Fig. Figure 2 shows that no potential difference exists between the electrodes 200, which have negative charges, and therefore the current I0 does not flow. However, a potential difference does exist between the electrodes 200, which carry positive and negative charges, and the current I1 therefore flows, so that a current can be supplied without an additional or separate power input.

[0032] The dielectric material layer 100 can be formed from at least one of the following materials: polymethyl methacrylate (PMMA), polyethylene (PE), polystyrene (PS), polyvinylpyrrolidone (PVP), poly(4-vinylphenol) (PVP) or polyethersulfone (PES), poly(4-methoxyphenyl acrylate) (PMPA), poly(phenyl acrylate) (PPA), poly(2,2,2-trifluoroethyl methacrylate) (PTFMA), cyanoethyl pullalan (CYEPL), polyvinyl chloride (PVC), poly(parabonic acid) resin (PPA), poly(t-butylstyrene) (PTBS), polythienylene vinylene (PTV), polyvinyl acetate (PVA), polyvinyl alcohol (PVA), poly(methylstyrene) (PAMS), poly(vinyl alcohol)-co-poly(vinyl acetate)-co-poly(itaconic acid) (PVAIA), polyolefin, polyacrylate, parylene-C, polyimide, octadecyltrichlorosilane (OTS), Poly(triarylamine) (PTTA), Poly-3-hexylthiophene (P3HT), cross-linked poly-4-vinylphenol or cross-linked PVP, Poly(perfluoroalkenyl vinyl ether), Nylon-6, n-Octadecylphosphonic acid (ODPA), Polytetrafluoroethylene (PTFE), Silicone, Polyurethane, Latex, Cellulose acetate,Poly(hydroxyethyl methacrylate) (PHEMA), polylactide (PLA), polyglycolide (PGA), and polyglycolide-co-lactide (PGLA).

[0033] Furthermore, electrode 200 can be formed from an inorganic electrode containing at least one of: indium tin oxide (ITO), indium gallium oxide (IGO), chromium, aluminum, indium zinc oxide (IZO), indium gallium zinc oxide (IGZO), ZnO, ZnO2 and TiO2, or a metal electrode containing at least one of: platinum, gold, silver, aluminum, iron and copper, or an organic electrode containing at least one of: polyethylene dioxythiophene (PEDOT), a carbon nanotube (CNT), graphene, polyacetylene, polythiophene (PT), polypyrrole, polyparaphenylene (PPV), polyaniline, polysulfur nitride, a stainless steel, an iron alloy containing 10% or more chromium, steel of the type Steel-Use-Stainless-(SUS) 304, SUS 316, SUS 316L, a Co-Cr alloy, a Ti alloy, Ni-Ti and polyparaphenylene vinylene.

[0034] As in the Fig. As shown in Figures 3-6, the energy harvesting system based on inverse electrowetting on a dielectric further comprises: a cover layer 300 formed from a hydrophobic substance in a plate form, coupled to the upper surface of the dielectric material layer 100 and configured to allow the liquid droplet W, W1, W2 to flow along an upper surface of the cover layer 300.

[0035] Therefore, the cover layer 300 prevents or hinders wetting of the energy harvesting system based on inverse electrowetting on a dielectric by the liquid droplet W, W1, W2 and allows the liquid droplet W, W1, W2 to flow uniformly along the upper surface of the energy harvesting system based on inverse electrowetting on a dielectric.

[0036] Furthermore, the energy harvesting system based on inverse electrowetting on a dielectric also comprises: a base substrate 400, which is coupled to the lower surface of the dielectric material layer 100 and the plurality of electrodes 200. The dielectric material layer 100 and the plurality of electrodes 200 are supported by the base substrate 400, thus contributing to ensuring the rigidity of the energy harvesting system based on inverse electrowetting on a dielectric.

[0037] As in the Fig. As shown in Figure 2-6, the dielectric material layer 100 comprises: a first section 110, which is inclined at a predetermined angle by the curved section 150, and a second section 120, which is inclined at an angle greater than that of the first section 110. The first section 110 and the second section 120 are arranged alternately such that the dielectric material layer 100 can extend by having the successive curved sections 150. The angle of inclination of the first section 110 will be different from that of the second section 120, so that the rate or flow rate F1 of a liquid droplet W1 approaching the first section 110 is faster or greater than the rate or flow rate F2 of a liquid droplet W2 moving away from the first section 110.Therefore, the polarity of electrode 200, generated by the liquid droplet W1 approaching the first section 110, has negative charges, and the liquid droplet W2, moving away from the first section 110, remains in the first section 110 for a longer period, and therefore the second section 120 has positive charges relative to the first section 110, so that a potential difference occurs between the first section 110 and the second section 120 to generate the current I1.

[0038] As in the Fig. As shown in Figures 2-3, the majority of electrodes 200 can be coupled to the lower surfaces of the first section 110 and the second section 120 of the dielectric material layer 100. The upper and lower ends of the electrode 200 coupled to the first section 110 are arranged at positions aligned with the upper and lower ends of the first section 110, the upper and lower ends of the electrode 200 coupled to the second section 120 are arranged at positions aligned with the upper and lower ends of the second section 120, and the upper and lower ends of the electrode 200 coupled to the first section 110 are spaced apart from those of the electrode 200 coupled to the second section 120.

[0039] According to another embodiment, the electrodes can be 200, as in Fig. As shown in Figure 4, the curved sections 150 of the first section 110 and the second section 120 are coupled via their lower surface. Therefore, the plurality of electrodes 200 are arranged differently, making it possible to control the time during which the liquid droplet W remains on the plurality of electrodes 200, thus allowing the amount of current that can be applied to be adjusted.

[0040] Alternatively, the curved sections 150 of the first section 110 and the second section 120 can be used, as in the Fig. As shown in Figures 5-6, the electrodes are formed in a curved line shape. The majority of electrodes 200 can be coupled to the lower surfaces of the first section 110 and the second section 120 of the dielectric material layer 100, and alternatively, the majority of electrodes 200 can be coupled to the curved sections 150 of the first section 110 and the second section 120 via their lower surfaces. Therefore, the curved section 150 is formed in a curved line shape, such that the rate of liquid droplet W at the curved section 150 is varied linearly, and the supplied current is also varied linearly.

[0041] As in Fig. As shown in Figure 7, each of the plurality of electrodes 200 is configured with first electrodes 210 and second electrodes 220, and the first electrodes 210 and the second electrodes 220 are arranged alternately on the lower surface of the dielectric material layer 100. A pair of feed devices 250 is further provided at both ends of each of the plurality of electrodes 200 to allow current flow. The first electrodes 210 can be connected to the feed device 250 provided on one side of each of the plurality of electrodes 200, and the second electrodes 220 can be connected to the feed device 250 provided on the other side of each of the plurality of electrodes 200.As described above, the majority of electrodes 200 are integrally connected by the pair of feed devices 250, so that one advantage is that the amount of feedable current can be increased or maximized. Furthermore, as in . Fig. Figure 7 shows that the energy harvesting system based on inverse electrowetting on a dielectric can operate a device C and the like using the current generated by connecting a wire to the pair of feed devices 250, which are provided on both sides of each of the plurality of electrodes 200, or can be used as a battery by connecting an electrical capacitor C to the pair of feed devices 250.

[0042] According to the present disclosure, an energy harvesting system based on inverse electrowetting on a dielectric is provided, which converts mechanical energy into electrical energy using a movement of a liquid droplet easily visible from the environment without a separate power supply.

[0043] This results in a particular economic advantage, as energy can be obtained without additional costs using a liquid droplet that is easily visible from the surroundings, such as a raindrop in contact with a building window.

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