Water purification system and method

Abstract

Embodiments provided herein relate to a water purification system and method that utilizes a filter cartridge comprising a plurality of stacked filter discs to form a plurality of channels for unfiltered water to flow through for purification. The water purification system is configured to utilize an exclusion zone phenomenon to separate impurities from water using a hydrophilic surface and a trifurcate structure to divert pure water from the impurities. A filter cartridge including a plurality of filter discs may be received by a water container to provide a low energy consumption water purification system.

Description

Technical Field

[0001] This invention generally relates to a water purification system for removing impurities from water. Background Technology

[0002] With population growth and increasing water scarcity, low-cost, near-zero-energy drinking water filtration is likely to become increasingly important for municipalities and the general public. Traditional water filtration systems, including reverse osmosis and distillation, require significant energy and / or expensive filters to remove impurities from water. There is a need for a more cost-effective, near-zero-energy water filtration system that is affordable for municipalities and the general public. Furthermore, there may be a need for a low-cost, low-energy desalination system that allows the large quantities of water obtained from the ocean to be utilized as a water resource without concerns about energy / electricity infrastructure to support purification. Additionally, systems with minimal or no scaling, or those that do not require frequent module replacements due to clogging, are needed, especially for desalination purposes, so that seawater can be used as a freshwater source without concerns about energy infrastructure to support purification, scaling, and constant module replacements due to clogging.

[0003] Therefore, there is a need to improve and enhance existing water purification system designs. Examples of new and practical water purification systems relevant to this need will be discussed below. Summary of the Invention

[0004] This summary is provided to introduce various concepts in a simplified form, which will be further disclosed in the detailed description of the embodiments. This summary is not intended to identify key inventive concepts or basic inventive concepts of the claimed subject matter, nor is it intended to define the scope of the claimed subject matter.

[0005] The embodiments provided herein relate to a system and method for water purification. In some embodiments, the water purification system includes: a plurality of filter wafers, wherein each filter wafer includes: a plurality of first channels extending from a proximal end of the filter wafer toward a distal end of the filter wafer, each of the first channels including a first sidewall and a second sidewall; and a plurality of trifurcation structures disposed at the distal end of each of the first channels, each trifurcation structure dividing the first channel into a second channel, a third channel, and a fourth channel, wherein the fourth channel is parallel to the first channel, and wherein the second channel and the third channel are disposed through the body of the filter wafer, wherein each of the first channel, the second channel, the third channel, and the fourth channel includes a hydrophilic surface; and wherein unfiltered water enters the plurality of first channels of the plurality of filter wafers, and purified water is diverted from each first channel into the second channel and the third channel.

[0006] In some embodiments, the plurality of filter elements are anoly bonded together to form a filter stack. In some embodiments, the system further includes a bottom cover disposed at the bottom of the filter stack, wherein the bottom cover includes cutouts for receiving purified water from a plurality of second and third channels of the filter stack. In some embodiments, the plurality of second and third channels of each filter element form a purified water channel through the filter stack, wherein the purified water channel is orthogonally arranged relative to the plurality of first channels. In some embodiments, the system further includes a top cover disposed on the top of the filter stack. In some embodiments, the bottom cover and the top cover are anoly bonded to the filter stack to form a filter element. In some embodiments, the plurality of filter elements, the top cover, and the bottom cover comprise silicon wafers or glass substrates. In some embodiments, the filter stack is hermetically sealed using a hydrophilic adhesive, sputtered titanium annealing, direct silicon fusion bonding, or thermocompression bonding. In some embodiments, impurity water is diverted from the first channels to the fourth channels. In some embodiments, the impurity water is discharged from an impurity water outlet formed by the distal ends of the plurality of fourth channels. In some embodiments, the three-way bifurcation structure includes a first bifurcation channel in fluid communication with the second channel and a second bifurcation channel in fluid communication with the third channel.

[0007] In some embodiments, depending on the complexity and precision of the microfabrication technique used, the first and second diversion channels each form an angle of 1 to 30 degrees, 30 to 60 degrees, 60 to 90 degrees, 90 to 120 degrees, 120 to 150 degrees, or 150 to 179 degrees with respect to the first channel. In some embodiments, depending on the hydrophilic material lining the channel, the widths of the first and second diversion channels are approximately 1 to 10 micrometers, 10 to 60 micrometers, 60 to 100 micrometers, or 100 to 200 micrometers. In some embodiments, depending on the width selected for the diversion channel, the first channel has a width of approximately 200 to 600 micrometers. In some embodiments, the fourth channel has a width of approximately 140 to 500 micrometers.

[0008] This document provides an embodiment of a water purification system, comprising: a plurality of filter elements, each filter element including: a plurality of first channels extending from a proximal end of the filter element toward a distal end of the filter element, each of the first channels including a first sidewall and a second sidewall, wherein the first sidewall and the second sidewall include a hydrophilic surface; and a plurality of tri-branching structures disposed at the distal end of each of the first channels, each tri-branching structure dividing the first channel into a second channel, a third channel, and a fourth channel, wherein the fourth channel is parallel to the first channel, and wherein the second channel and the third channel extend through the body of the filter element, wherein unfiltered water enters the plurality of first channels of the plurality of filter elements, and purified water is diverted from each first channel to the second channel and the third channel; and a water container for receiving the plurality of filter elements and guiding the unfiltered water into the plurality of first channels of the plurality of filter elements.

[0009] In some embodiments, the water container supplies unfiltered water to the plurality of first channels at a pressure head of at least 15 cm to 2 meters. In some embodiments, the system further includes a bottom cover disposed on the bottom of the plurality of filter elements, wherein the bottom cover includes a cutout providing an outlet for purified water received from the plurality of second and third channels, and wherein the outlet is located outside the body of the water container when the plurality of filter elements are received by the water container. In some embodiments, the system further includes a top cover disposed on top of the plurality of filter elements, wherein the plurality of filter elements, the bottom cover, and the top cover are anodized to form a filter element, and wherein the water container receives the filter element. In some embodiments, the system further includes a top cover disposed on top of the plurality of filter elements, wherein the plurality of filter elements, the bottom cover, and the top cover are hermetically sealed using a hydrophilic adhesive, or using sputtered titanium annealing, or direct silicon fusion bonding, or thermocompression bonding. Attached Figure Description

[0010] A more complete understanding of the embodiments and their accompanying advantages and features will be more readily understood when considered in conjunction with the accompanying drawings, by referring to the following detailed description, wherein: Figure 1A A perspective view of a water purification system according to some embodiments is depicted; Figure 1B A bottom view of a water purification system according to some embodiments is depicted; Figure 1C A top perspective view of a water purification system according to some embodiments is depicted; Figure 2 A top perspective view of the bottom cover component of a water filter cartridge according to some embodiments is depicted; Figure 3A A top perspective view of a water filter cartridge according to some embodiments is depicted; Figure 3B A rear view of a water filter cartridge according to some embodiments is depicted; Figure 3C A front view of a water filter cartridge according to some embodiments is depicted; Figure 3D A left-side view of a water filter cartridge according to some embodiments is depicted; Figure 4A A top perspective view of a filter element component of a water filter cartridge according to some embodiments is depicted; Figure 4B A detailed cross-sectional view of the filter element component of a water filter cartridge according to some embodiments is depicted; Figure 4B A detailed cross-sectional view of the filter element component of a water filter cartridge according to some embodiments is depicted; Figure 4C A detailed cross-sectional view of the filter element component of a water filter cartridge according to some embodiments is depicted; Figure 4D A detailed cross-sectional view of the filter element component of a water filter cartridge according to some embodiments is depicted; Figure 5 A perspective view of an unfiltered water container component of a water purification system according to some embodiments is depicted. Figure 6 A serial channel configuration of a filter element according to some embodiments is depicted; Figure 7 Parallel-to-serial channel configurations of filter components according to some embodiments are depicted; Figure 8A An exclusion zone formed in a channel of a filter element according to some embodiments is depicted; and Figure 8B An exclusion zone formed in the channel of a filter element according to some embodiments is depicted. Detailed Implementation

[0011] The specific details of one or more embodiments described herein relate to the described system and method of use. Any specific details of the embodiments are for illustrative purposes only and should not be interpreted as unnecessarily limiting or inferences.

[0012] Before describing the exemplary embodiments in detail, it is worth noting that these embodiments are primarily embodied in the combination of system-related components and programs. Therefore, system components are indicated in appropriate places by conventional symbols in the accompanying drawings, and only those specific details relevant to understanding embodiments of this disclosure are shown, so as not to obscure this disclosure with details that will be readily apparent to those of ordinary skill in the art who will benefit from the description herein.

[0013] The embodiments provided herein generally relate to a water purification system including a water filter cartridge. In some embodiments, the water purification filter cartridge includes multiple stacked filter discs. This stack of filter discs may be collectively referred to as a filter cartridge. In some embodiments, the filter cartridge includes multiple filter discs (forming a filter disc stack or filter pile), a top cover, and a bottom cover.

[0014] In some embodiments, each of the filter elements includes multiple channels. A first channel may also be referred to as an inlet channel or an unfiltered water channel. In some embodiments, unfiltered water enters multiple first channels formed by multiple filter elements. In some embodiments, multiple distal ends of the first channels form multiple inlets. These inlets may be collectively referred to as the inlets of the filter element.

[0015] In some embodiments, the first channel includes a hydrophilic surface. As unfiltered water flows through the first channel, the hydrophilic surface forms a rejection zone where pure water (i.e., H2O) accumulates against the hydrophilic surface, repelling impurities and causing the water in the first channel to stratify. In some embodiments, each of the first channels formed in the filter includes a three-pronged structure. In some embodiments, due to the rejection zone created by the hydrophilic surface, the water flowing in the first channel stratifies upon reaching the three-pronged structure. In some embodiments, the three-pronged structure guides the outer portion of the water flowing through the first channel into the second and third channels.

[0016] In some embodiments, the water entering the second and third channels is pure water due to the hydrophilic surface of the first channel causing stratification of pure water. Therefore, the second and third channels can be collectively referred to as purified water channels. In some embodiments, the purified water channels are orthogonal to the planar arrangement formed by the filter element body. In some embodiments, when the filter elements are stacked, the purified water channels are formed through the filter element stack or filter pile, such that purified water from each of the filter elements is discharged through the bottom of the filter pile. The purified water from each of the purified water channels in the filter pile can be directed to multiple outlets. These outlets can be collectively referred to as purified water outlets of the filter pile. In some embodiments, the bottom cover or base includes a cutout that collects the purified water discharged from the purified water outlet and provides a purified water outlet for the entire filter element including the filter element stack.

[0017] In some embodiments, multiple fourth water channels are configured parallel to the first water channel. In some embodiments, pure water is diverted from the first channel to the second and third channels (purified water channels), while impurities flow into the fourth channels. Therefore, the fourth channels may be collectively referred to as wastewater channels or impurity water channels. Multiple impurity water channels may form an impurity water outlet comprising a filter cartridge consisting of stacked filter elements. In some embodiments, impurity water from the multiple impurity water channels may be collected and / or diverted from the impurity water outlet.

[0018] Figure 8A and Figure 8B The separation of pure water and impurities in a channel caused by the exclusion zone phenomenon according to some embodiments is described. In some embodiments, unfiltered water enters a first channel 801, which includes a hydrophilic inner surface. When pure water is attracted to the hydrophilic surface, it repels impurities or particles in the unfiltered water toward the center of the channel. The repulsive force 850 generated by the exclusion zone phenomenon causes solute particles suspended in the unfiltered water to be expelled from the vicinity of the hydrophilic inner surface, thereby forming a larger layer and separating the pure water 820 from the aqueous solution containing concentrated impurities 825.

[0019] like Figure 8A As shown, the three-branched structure including the diversion channel 815 utilizes the exclusion zone phenomenon to divert and concentrate pure water, while unfiltered water with concentrated impurities 825 continues downstream into the subsequent channel 804. As described herein, the inner surface (exclusion surface) of channel 801 can be formed of or coated with a hydrophilic material to create an exclusion zone, wherein pure liquid water and impurities suspended in the water source are stratified.

[0020] The purification system described herein may include a water container for receiving unpurified water and directing it to the inlet of a filter cartridge. The system may utilize gravity for purification to complete the filtration process, thereby providing a low-energy or zero-energy filtration system. Those skilled in the art will understand that the filter cartridges described herein can be used in a variety of systems, including systems for specific applications that utilize pumps adjacent to the inlet and / or outlet of the filter cartridge.

[0021] The purification system described herein can be used to remove various impurities from water sources. For example, the purification system can be used to remove salt / salt water from seawater or brackish water sources. In some embodiments, the purification system can be used to remove substances from freshwater sources to produce purified water. In some embodiments, the purification system can be used to remove dissolved solutes, ions, suspended particles, bacteria, viruses, organic compounds, inorganic compounds, or similar unwanted impurities from water sources. However, the purification system's ability to remove certain toxins or toxic compounds may be limited, as these toxins or toxic compounds may damage the exclusion zone responsible for purification.

[0022] Water filtration system Figures 1A-1C A water filtration system according to some embodiments is described. In some embodiments, the water filtration system includes an unpurified water container 150 and a water filter cartridge 100. The water container 150 can hold a volume of unpurified water. In some embodiments, the water container 150 receives the filter cartridge 100 and directs the unfiltered water to the inlet of the water filter cartridge 100 for purification. The water container 150 provides the necessary water head so that water can be forced through the filter cartridge 100 under gravity without any additional pump or energy input.

[0023] In some embodiments, the filter element 100 includes one or more filter plates, each including a plurality of first channels 101 that guide unfiltered water to a three-way bifurcation structure 105, as further described below. The proximal end of the first channel 101 (e.g. Figure 4A The first channel 101 (described as 411) can form an inlet for unfiltered water to enter the filter element 100. The multiple inlets formed by the proximal end of the first channel 101 can be collectively referred to as the inlets of the filter element 100.

[0024] Multiple first channels 101 may include hydrophilic surfaces, allowing unfiltered water to stratify before reaching the trifled structure 105. The trifled structure 105 may guide pure water through purified water channels 103 orthogonally arranged relative to the plane formed by the stacked filter elements, and into a cutout on the bottom cover 135 of the filter element 100 (e.g., Figure 2 The purified water outlet 125 is formed (described as 225 in the text).

[0025] In some embodiments, the three-pronged structure 105 directs water containing concentrated impurities into an impurity water channel 104 arranged parallel to the unfiltered water channel 101. The water containing concentrated impurities can be discharged from the distal end of the filter element, i.e., from the distal end of the impurity water channel 104. The distal end of the impurity water channel 104 can be collectively referred to as the impurity water outlet 114 of the filter element 100.

[0026] Figure 1B A bottom view of a water container 150 according to some embodiments is depicted, wherein a filter element 100 is received within the cavity of the water container 150. When received by the water container 150, a purified water channel 103 and a purified water outlet 125 may be provided outside the body of the water container 150, thereby preventing obstruction of the flow of purified water from the filter element 100.

[0027] Figure 1C A top perspective view of a water container 150 according to some embodiments is depicted, wherein a filter cartridge 100 is received within the cavity of the water container 150, and a top cover (e.g.) Figure 1A The character depicted as 130 has been removed. Figure 1C The diagram also shows a three-pronged structure 105 according to some embodiments and an inlet to a purified water channel 103 located outside the body of the water container 150, thereby preventing obstruction of the flow of purified water from the filter element 100.

[0028] Filter cartridge Figures 3A-3D A filter element 300 according to some embodiments is depicted. In some embodiments, the filter element 300 includes stacked filter sheets 310, a top cover 330, and a bottom cover 335. In some embodiments, the filter sheets 310 are anodized together to form a hermetically sealed seal. The hermetically sealed seal can also be achieved by several other processes, including but not limited to: sputtering the sheet surfaces with titanium and thermally bonding them under pressure; bonding the sheets using hermetically sealed adhesives, such as spin coating; silicon fusion bonding; or thermocompression bonding. In some embodiments, the top cover 330 and / or the bottom cover 335 are anodized to the top and bottom of the stacked filter sheets 310, respectively. In some embodiments, the hermetically sealed seal can also be formed by annealing. Annealing may include sputtering the surfaces of the filter sheets 310 and / or the top and bottom covers with titanium and thermally bonding the filter sheets together under pressure. In some embodiments, an airtight seal can be formed by coating and bonding the filter sheet and / or top and bottom covers together with a hydrophilic adhesive, such as a sulfonated tetrafluoroethylene vinyl fluoropolymer copolymer (e.g., NAFION), a sheet bonding adhesive (e.g., PERMINEX), other suitable adhesives, or combinations thereof. The sealing adhesive can be spin-coated onto the filter sheet. An airtight seal can also be achieved by silicone fusion bonding, thermoforming, other suitable bonding methods, or combinations thereof.

[0029] Figure 3B A rear view of a filter element 300 according to some embodiments is depicted, and the inlet of a first channel 301 (unfiltered water channel) is shown, which together form the unfiltered water inlet of the filter element. Figure 3C A front view of a filter element 300 according to some embodiments is depicted, and the outlet of a fourth channel 304 (impurity water channel) is shown, which together form the impurity water outlet of the filter element. Figure 3D A left-side view of the filter element 300 is depicted, showing the purified water outlet 325 of the water filter element 300. (Reference) Figure 3D According to some embodiments, unfiltered water flows from left to right, entering the unfiltered water inlet 311 formed by the proximal end of the first channel, and flows towards the three-way bifurcation structure. Further reference... Figure 3D After the pure water and impurities are separated at the three-way bifurcation structure, the impurity water will be discharged from the impurity water outlet 314 formed by the far end of the fourth channel, and the purified water will flow out from the purified water outlet 325 provided by the bottom cover 335.

[0030] refer to Figure 3A The image depicts a perspective view of a filter element 300 according to some embodiments. In some embodiments, unfiltered water enters a plurality of first channels 301 disposed in each of the filter elements 310. Water can be forced into the channels by a pressure head (e.g., a pressure head provided by a water container as described herein), the hydrophilic surface of the first channel, or a combination thereof. Figure 3A As depicted, unfiltered water flows from the first channel to the three-way bifurcation structure 305 (from left to right).

[0031] As described herein, one or more surfaces of the first channel 301 are hydrophilic, and when unfiltered water flows through the first channel 301, the unfiltered water stratifies due to a rejection zone phenomenon. This stratification caused by the hydrophilic surfaces causes pure water to accumulate against the hydrophilic surfaces (on the outside of the first channel) and repels impurities away from the hydrophilic surfaces (towards the center of the first channel). In some embodiments, the unfiltered water flows to the tri-branch structure 305, where purified water that has accumulated towards the outside of the first channel is diverted to the purified water channel 303, while concentrated impurities continue to flow into the impurity water channel 304.

[0032] In some embodiments, the stacked and / or joined filter elements 310 provide a continuous purified water channel 303 arranged throughout the stacked filter elements. Purified water from each of the filter elements can then flow into a cutout (e.g., on the bottom cover 335 of the filter element 300) provided on the filter element. Figure 2 It is described as 225), and flows out from the purified water outlet 325.

[0033] In some implementations, stacked filter elements 310 allow for modular construction, enabling the fulfillment of specific flow rate requirements while maintaining low cost as much as possible. For example, users requiring a higher volumetric water filtration output can use a filter cartridge 300 comprising twenty or more filter elements 310, while users requiring a lower volumetric water filtration output can use a filter cartridge 300 comprising ten filter elements. Increasing water filtration output requirements may simply require a larger number of filter elements without any additional modifications to the filter cartridge, thus providing a low-cost solution for customized water filtration needs. Furthermore, the width of the filter elements can be increased to increase the number of channels arranged through each element, thereby increasing the water filtration rate.

[0034] In some embodiments, as described herein, a water container can be provided to receive the filter cartridge 300, and a pressure head can be provided at the filter cartridge inlet to allow filtration to occur under gravity. Furthermore, the filter cartridge design can be applied to a variety of scenarios, utilizing various water inlets and / or outlets. For example, a manifold can connect the filter cartridge inlet 311 to a conduit providing a pressurized water source. Other manifolds can also be used to connect, for example, a purified water outlet 325 to a conduit to divert purified water to a tank or outlet away from the filter cartridge. Similarly, a manifold can connect a contaminated water outlet 314 to a conduit to divert contaminated water away from the filter cartridge for treatment. According to some embodiments, the filter cartridge can be used in a cascade system, where contaminated water from a first filter cartridge can be diverted to a second filter cartridge to increase the extraction of purified water.

[0035] In some embodiments, filter 310, top cover 330, and bottom cover 335 comprise silicon wafers. The silicon wafers can be used for simple micromachining using laser cutting (e.g., laser etching or laser ablation using a laser computer numerical control (CNC) system), deep reactive ion etching, and / or time-multiplexed etching (e.g., Bosch process). In some embodiments, the simple micromachining process may include deep reactive ion etching and / or the Bosch process. In some embodiments, other materials may be used to form filter 310, top cover 330, and bottom cover 335, including but not limited to metals, plastics / polymers, glass, or other materials that may be suitable for micromachining or processing the channels of the filter.

[0036] In some embodiments, filter element 310, top cover 330, and / or bottom cover 335 comprise a hydrophilic material. In some embodiments, filter element 310, top cover 330, and / or bottom cover 335 are made of a hydrophilic material. In some embodiments, filter element 310, top cover 330, and / or bottom cover 335 comprise a hydrophilic coating. This hydrophilic coating may comprise a sulfonated tetrafluoroethylene fluoropolymer copolymer (e.g., NAFION), hydrophilic silica, polyacrylic gel, hydrogel, hydrophilic polymer surface, ACULON hydrophilic coating, carbon nanoparticles hydrolyzed in an alkaline environment, other materials suitable for providing a hydrophilic coating, or combinations thereof. The hydrophilic coating may be applied using spin coating, microimprinting, physical vapor deposition, or combinations thereof. In some embodiments, only a portion of filter element 310, top cover 330, and / or bottom cover 335 comprises a hydrophilic coating. This hydrophilic coating may be applied to the filter element after processing the channel.

[0037] According to some embodiments, the filter surface can be naturally hydrophilic, or it can be made hydrophilic by deposition of materials such as Nafion, hydrophilic silica, aculon, or carbon nanoparticles hydrolyzed in an alkaline environment. Such materials can be applied using spin coating, microimprinting, or physical vapor deposition.

[0038] filter Figures 4A-4D A filter element 410 according to some embodiments is depicted. As described herein, multiple filter elements 410 may be stacked to form part of a filter cartridge. In some embodiments, an unfiltered water channel 401, a three-pronged structure 405, and a contaminant water channel 404 are formed on the top surface of each filter element 410. In some embodiments, a purified water channel 403 is formed through the body of each filter element 410. If the base material is silicon, the purified water channel may also be referred to as a through-hole, cutout, aperture, or via. In some embodiments, where the filter element 410 is made of silicon, the purified water channel may be referred to as a through-silicon via. In some embodiments, the purified water channels are arranged orthogonally through a plane formed by the body of the filter element 410 (i.e., through the thickness of the filter element).

[0039] When stacked, the bottom surface of the first filter element can form the top surface of the unfiltered water channel and impurity water channel of the second filter element located directly below the first filter element. Furthermore, when stacked, the purified water channel 403 of all the stacked filter elements can form a continuous channel running through the entire stack (i.e., a continuous channel from the top filter element to the bottom filter element). In some embodiments, the filter elements of the filter cartridge are anodicly bonded together to form an airtight seal. An airtight seal can also be achieved through several other processes, including but not limited to: sputtering the sheet surface with titanium and thermally bonding under pressure, known as annealing; bonding the sheets using airtight sealant adhesives, such as spin-coating with Nafion, Perminex, or other similar processes; silicon fusion bonding; or thermocompression bonding.

[0040] In some embodiments, the hermetic seal can also be formed by annealing. Annealing may include sputtering the surface of filter 410 with titanium and thermally bonding the filter sheets together under pressure. In some embodiments, the hermetic seal can be formed by coating and bonding the filter sheets and / or top and bottom covers together with a sealing adhesive such as a sulfonated tetrafluoroethylene vinyl fluoropolymer copolymer (e.g., NAFION), a sheet bonding adhesive (e.g., PERMINEX), other suitable adhesives, or combinations thereof. The sealing adhesive may be spin-coated onto the filter sheets. The hermetic seal can also be achieved by silicon fusion bonding, thermocompression bonding, other suitable bonding methods, or combinations thereof.

[0041] In some embodiments, each filter element 410 includes a plurality of first channels or unfiltered water channels 401 for receiving unfiltered water. In some embodiments, unfiltered water flows in the first channels 401 toward a three-way bifurcation structure 405, wherein purified water that has accumulated toward the outside of the first channels due to exclusion zones formed by the hydrophilic surfaces of the first channels is diverted to purified water channels 403, while concentrated impurities continue to flow into impurity water channels 404.

[0042] refer to Figure 4A The proximal end 411 of the unfiltered water channel 401 may be tapered to form an inlet to the channel. In some embodiments, the tapering at the proximal end 411 enhances capillary forces to draw water into the first channel 401. In some embodiments, the distal end 414 of each impurity water channel 404 includes a tapering.

[0043] refer to Figure 4B and Figure 4C A detailed view of filter 410 is depicted, showing a three-way bifurcation structure 405. In some embodiments, the distal end of each unfiltered water channel 401 leads to or terminates at the three-way bifurcation structure 405. In some embodiments, the three-way bifurcation structure 405 includes a pure water diversion channel 415. In some embodiments, a first diversion channel diverts water to a second channel (purified water channel), and a second diversion channel diverts water to a third channel (another purified water channel). As described herein, the hydrophilic surfaces disposed in the unfiltered water channels 401 cause the unfiltered water to stratify, such that pure water accumulates on the outside of the unfiltered water channels, while impurities in the unfiltered water are pushed towards the center of the channels. The diversion channel 415 diverts pure water from the outside of the unfiltered water channels into the purified water channels. Impurities accumulating towards the center of the unfiltered water channels can then flow into the impurity water channel 404. Thus, each three-way bifurcation structure can be used to separate purified water from water containing concentrated impurities.

[0044] In some embodiments, the diversion channel 415 forms a 45° angle with the unfiltered water channel 401. In some embodiments, the angle between the diversion channel 415 and the unfiltered water channel 401 is about 15 degrees to about 30 degrees, about 30 degrees to about 45 degrees, or about 45 degrees to about 60 degrees. Depending on the precision of the micromachining tool, this angle can also be 1 degree to 15 degrees, 60 degrees to 90 degrees, 90 degrees to 120 degrees, 120 degrees to 150 degrees, or 150 degrees to 179 degrees. In some embodiments, the three-pronged structure narrows the unfiltered water channel 401 relative to the impurity water channel 404, such that the width of the impurity water channel 404 is smaller than the width of the unfiltered water channel 401.

[0045] Figure 4DA detailed rear view of filter element 410 is depicted. In some embodiments, each first channel 401 of the filter element includes a bottom wall 418, a first side wall 416, and a second side wall 417. In some embodiments, when stacked, the bottom surface 419 of the first filter element forms the top surface or top wall of each of the first channels of the second filter element stacked directly below the first filter element. Similarly, each fourth channel of the filter element includes a bottom wall, a first side wall, a second side wall, and a top wall (formed by the bottom surface of the top plate). The bottom wall, first side wall, second side wall, and top wall may be collectively referred to as the wall or inner surface of the channel. In some embodiments, the top cover of the filter element provides a top surface or top wall for the filter elements at the top of the filter stack.

[0046] In some embodiments, each filter element is composed of a hydrophilic material. In some embodiments, the hydrophilic coating is applied to the entire filter element. In some embodiments, the hydrophilic coating is applied to a portion of each filter element. In some embodiments, the hydrophilic coating is applied to the wall or inner surface of each channel (i.e., the wall forming the first channel, second channel, third channel, fourth channel, and diversion channel). The hydrophilic coating may include sulfonated tetrafluoroethylene vinyl fluoropolymer copolymers (e.g., NAFION), hydrophilic silica, polyacrylic acid gel, hydrogel, hydrophilic polymer surface, ACULON hydrophilic coating, carbon nanoparticles hydrolyzed in an alkaline environment, polyvinylpyrrolidone (PVP), polyurethane, polyacrylic acid (PAA), polyethylene oxide (PEO), polysaccharide materials, hydrophilic silica (e.g., silica prepared by wet thermal oxidation of silicon wafers), other materials suitable for providing the hydrophilic coating, or combinations thereof.

[0047] In some embodiments, the filter consists of a silicon wafer, and channels in the silicon wafer are patterned using deep reactive ion etching. In some embodiments, after processing the channels, wet thermal oxidation is then performed on the silicon wafer. In some embodiments, titanium is then sputtered onto the back side of each patterned wafer. The filter wafers can then be bonded together using thermal annealing (high temperature and high pressure). Excess circular geometry in the original silicon wafer shape can then be removed. In some embodiments, NAFION or other hydrophilic hermetically sealed adhesives can be used instead of titanium. In some embodiments, laser micromachining is used to process the channels. In some embodiments, the filter wafers comprising the silicon wafer are bonded together using silicon fusion bonding. After bonding, wet oxidation or physical vapor deposition of a hydrophilic compound can be performed on the bonded wafers.

[0048] In some embodiments, the filter comprises glass, and the channels are formed by etching with hydrofluoric acid (HF). The glass filter can then be anoly bonded.

[0049] In some implementations, p-type and n-type sheets are used alternately to form a sheet stack, and anodic bonding is performed to bond the sheets together. After bonding, wet oxidation or physical vapor deposition of a hydrophilic material can be performed.

[0050] While the examples in this article include a three-way bifurcation structure to separate pure water from impurities in an unfiltered water supply, a two-way bifurcation system can also be implemented, where pure water is diverted from each unfiltered water channel to the purified water channel via a single diversion channel, rather than using two diversion channels on each side of the unfiltered water channel.

[0051] Exemplary Implementation The following examples are for illustrative purposes only and are not intended to limit the scope of this topic.

[0052] Exemplary water container Figure 5 An exemplary water container 500 according to some embodiments is depicted. In some embodiments, the water container 500 includes an unfiltered water inlet 510 for receiving unfiltered water. In some embodiments, the water container 500 is configured to use only gravity without any supplemental pump or energy input to provide a sufficiently large pressure head to move unfiltered water through a filter cartridge received within a filter cartridge chamber 550. Figure 5 (Not shown in the image). In some embodiments, depending on the capacity of the inlet container, the water inlet 510 includes a height 512 of approximately 15 cm to 2 meters (or variable), a width 513 of approximately 7 cm or equal to the width of the filter cartridge received by the water container, and a length 514 of approximately 4 cm or longer. In some embodiments, the water container 500 provides a pressure head of approximately 15 cm to 2 meters for the inlet of the filter cartridge chamber 550.

[0053] In some embodiments, the filter cartridge chamber 550 is sized such that the purified water outlet of the filter cartridge is located outside the body of the water container 500, so that the water container does not obstruct the flow of purified water from the purified water outlet. In some embodiments, the dimensions of the water container 500, water inlet 510, and filter cartridge chamber 550 are designed to accommodate the exemplary filter cartridge described herein. The dimensions of the water container 500, water inlet 510, and filter cartridge chamber 550 can be adjusted according to flow rate requirements (i.e., the required amount of water to be filtered per unit time).

[0054] In some embodiments, the water container 500 comprises silicone. In some embodiments, the water container 500 is made of any suitable material, including but not limited to plastics (e.g., polyethylene or polypropylene), glass, stainless steel, and combinations thereof.

[0055] Example filter cartridge Figures 3A to 3DAn exemplary water filter element 300 according to some embodiments is depicted. In some embodiments, the filter element 300 includes a length of about 7 cm and a width of about 7 cm. In some embodiments, the filter element includes ten filter discs 310. Each filter disc 310 may include a thickness of about 0.5 mm to 1 mm, and the stacking of ten filter discs forms a stack having a height of 5 mm to 10 mm. In some embodiments, the top cover 330 and the bottom cover of the filter element 300 each include a thickness of about 1 mm to 2 mm and have a width and length of about 7 cm to 20 cm. In some embodiments, the filter discs are formed using silicon wafers, and the length and width of the filter discs, as well as the corresponding top and bottom covers, depend on the size of the silicon wafer used to manufacture the filter discs. For example, a 4-inch or 100 mm diameter silicon wafer can be used to produce filter elements with a length and width of 7 cm, a 6-inch diameter silicon wafer can produce filter elements with a length and width of 10 cm, an 8-inch diameter silicon wafer can produce filter elements with a length and width of 13 cm, and a 12-inch diameter silicon wafer can produce filter elements with a length and width of 20 cm. In an exemplary embodiment, the height of the assembled filter element 300, including ten filter elements 310, a top cover 330, and a bottom cover 335, includes a height of approximately 7 to 14 mm. A rectangular substrate can also be formed. If a glass substrate is used, it can have larger dimensions than those described above. In cascaded designs, where multiple tri-branch structures can be present in a single channel, a longer length may be necessary to provide more layering.

[0056] In some embodiments, the cut on the bottom cover 335 forming the purified water outlet is approximately 20 mm wide and 0.5 to 1 mm deep. In some embodiments, the cut on the bottom cover 335 forming the purified water outlet is half the thickness of the cover. This cut may be located directly below the multiple purified water channels of the filter stack.

[0057] Exemplary filter Figures 4A to 4D An exemplary water filter 410 according to some embodiments is depicted. In some embodiments, the water filter includes a width of about 7 cm, a length of about 7 cm, and a thickness of about 0.5 mm. In some embodiments, each first water channel or unfiltered water channel 401 of the sheet is about 200 to 600 micrometers (µm or micron) wide (i.e., the spacing between the first sidewall 416 and the second sidewall 417 of each unfiltered channel is about 200 to 600 micrometers). In some embodiments, each unfiltered water channel 401 is about 100 to 500 micrometers deep, depending on the thickness and stability of the substrate used and the substrate material.

[0058] In some embodiments, the tri-branch structure 405 and the diversion channel 415 are disposed approximately 4 to 6 cm from the proximal end 411 of the first channel 401. In some embodiments, depending on the complexity and precision of the microfabrication technique used, the diversion channel 415 forms an angle with the first channel of approximately 1 to 30 degrees, 30 to 60 degrees, 60 to 90 degrees, 90 to 120 degrees, 120 to 150 degrees, or 150 to 179 degrees. In some embodiments, depending on the hydrophilic material lining the channel, the diversion channel 415 includes a width of approximately 1 to 10 micrometers, 10 to 60 micrometers, 60 to 100 micrometers, or 100 to 200 micrometers. In some embodiments, depending on the hydrophilic material lining the channel, the purified water channel 403 includes a width of approximately 1 to 10 micrometers, 10 to 60 micrometers, 60 to 100 micrometers, or 100 to 200 micrometers, and a length of approximately 1 to 2 mm. In some embodiments, the impurity water channel or fourth channel 404 is approximately 140 to 500 micrometers wide, depending on the combination of the width of the three-way bifurcated channel, the effectiveness of the hydrophilic material, and the desired flow rate. The impurity water channel 404 may be arranged parallel to the associated unfiltered water channel 401 and share the same central axis. According to some embodiments, all surfaces within the channel directly exposed to fluid flow, including the top, bottom, and sidewalls, may be hydrophilic.

[0059] Cascaded three-way bifurcation configuration In some embodiments, the filter element includes multiple unfiltered water channels that guide unfiltered water to multiple tri-branch structures, where a rejection zone phenomenon is utilized to separate pure water from impurities at each tri-branch structure. Because pure water is diverted at each tri-branch structure, the amount of pure water extracted from a given volume of unfiltered water can be increased without having to significantly increase the size of the filter element or filter cartridge.

[0060] Figure 6An example of a cascaded trifling configuration is depicted, wherein three trifling structures (615, 625, 635) are arranged in series along track 600. In some embodiments, unfiltered water enters the first channel 611 from water inlet 605. As described herein, the first channel may include an inner surface composed of a hydrophilic material, such that pure water is separated from impurities as unfiltered water moves through the channel. As described herein, in some embodiments, when water reaches the first trifling structure 615, pure water is diverted by a first diversion channel 614 into a first pure water channel 613. In some embodiments, water containing impurities continues into a second channel 621. The second channel may also include an inner surface composed of a hydrophilic material, such that pure water is separated from impurities as unfiltered water moves through the second channel. When water reaches the second trifling structure 624, pure water is diverted through the second diversion channel 624 into a second set of pure water channels 623. In some embodiments, water containing impurities continues into a third channel 631. The third channel may also include an inner surface made of a hydrophilic material, allowing pure water to separate from impurities as unfiltered water moves through it. When the water reaches the third tri-branch structure 634, the pure water is again diverted through the third branch channel 624 into the third set of pure water channels 633. At this point, the water with a high concentration of impurities can then continue into the fourth channel 641 and exit from the impurity water outlet 610.

[0061] Such a configuration can be processed into a filter element, such that multiple tracks 600 comprising a series of channels and tri-branched structures are formed on the filter element. As described herein, the filter element can be stacked to form a filter cartridge that utilizes a series of tri-branched structures along each track 600 to increase the amount of pure water extracted from a given volume of unfiltered water introduced into the filter cartridge. Although a track 600 comprising a series of three tri-branched structures is depicted, the number of tri-branched structures can be varied to form a series of tri-branched structures arranged in series, such as two, four, or five.

[0062] Figure 7An example of a cascaded tri-branch configuration is depicted, wherein four tri-branch structures (751, 752, 761, 762) are arranged in parallel along track 700. In some embodiments, unfiltered water enters water inlet 705 and flows into first channel 701. As described herein, the first channel may include an inner surface made of a hydrophilic material, such that pure water is separated from impurities as unfiltered water moves through the channel. In some embodiments, pure water is diverted to a first diversion channel 714. In some embodiments, the first diversion channel includes an inner surface made of a hydrophilic material, such that pure water is again separated from impurities as unfiltered water moves through the first diversion channel 714. At the first tri-branch structure 751 and the second tri-branch structure 752, pure water from the first diversion channel 714 is diverted to a pure water channel 713. In some embodiments, water containing impurities from the first diversion channel 714 is diverted to a second channel 702. In some embodiments, the second channel 702 includes an inner surface made of a hydrophilic material, such that pure water is separated from impurities as unfiltered water moves through the channel. In some embodiments, the pure water is then diverted to a second diversion channel 724. In some embodiments, the second diversion channel also includes an inner surface made of a hydrophilic material, such that pure water is again separated from impurities as unfiltered water moves through the second diversion channel 724. At the third and fourth tri-branch structures 761 and 762, pure water from the second diversion channel 724 is diverted to a pure water channel 723. In some embodiments, water containing impurities from the second diversion channel 724 is diverted to a third channel 703 and exits from the outlet 710 of the track 700.

[0063] Such a configuration can be processed into a filter element, such that multiple tracks 700 comprising tri-branched structures arranged parallel to the tracks are formed as the filter element. As described herein, the filter element can be stacked to form a filter cartridge that utilizes the parallel arrangement of the tri-branched structures along each track 700 to increase the amount of pure water extracted from a given volume of unfiltered water introduced into the filter cartridge. Although tracks 700 comprising four tri-branched structures arranged in a parallel configuration are depicted, the number of tri-branched structures can be varied to provide, for example, two, six, or eight tri-branched structures arranged in a parallel configuration.

[0064] The descriptions of various embodiments in this disclosure are for illustrative purposes and are not intended to be exhaustive or limiting. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein has been chosen to best explain the principles of the embodiments, their practical application, or technical improvements relative to technologies found in the market, or to enable others skilled in the art to understand the embodiments disclosed herein. Therefore, the appended claims should be interpreted broadly to include other variations and embodiments that may be made by those skilled in the art.

Claims

1. A water purification system, comprising: Multiple filter elements, wherein the filter elements include: A plurality of first channels extending from a proximal end of the filter towards a distal end of the filter, each of the first channels including a first sidewall and a second sidewall; and Multiple tri-branch structures are provided at the distal end of each of the first channels, each tri-branch structure dividing the first channel into a second channel, a third channel, and a fourth channel, wherein the fourth channel is parallel to the first channel, and wherein the second channel and the third channel extend through the body of the filter. Each of the first channel, the second channel, the third channel, and the fourth channel includes a hydrophilic surface; and unfiltered water enters the plurality of first channels of the plurality of filter elements, while purified water is diverted from each first channel to the second channel and the third channel.

2. The system according to claim 1, wherein, The plurality of filter elements are anodized together to form a filter stack by at least one of the following methods: hermetically sealed hydrophilic adhesive, titanium sputtering annealing, direct silicon fusion bonding, or hot pressing bonding.

3. The system of claim 2, further comprising a bottom cover disposed at the bottom of the filter stack, wherein, The bottom cover includes cutouts for receiving purified water from multiple second and third channels of the filter stack.

4. The system according to claim 3, wherein, The plurality of second channels and the third channels of each filter element form a purified water channel through the filter stack, wherein the purified water channel is arranged orthogonally to the plurality of first channels.

5. The system of claim 4, further comprising a top cover disposed on top of the filter stack.

6. The system according to claim 5, wherein, The bottom cover and the top cover are anodized to the filter stack to form a filter element by at least one of the following methods: airtight hydrophilic adhesive, titanium sputtering annealing, direct silicon fusion bonding, or hot pressing bonding.

7. The system according to claim 6, wherein, The plurality of filter elements, the top cover, and the bottom cover comprise at least one of a silicon wafer or a glass substrate.

8. The system according to claim 2, wherein, The filter stack is hermetically sealed using hydrophilic adhesives, sputtered titanium annealing, direct silicon fusion bonding, or hot-press bonding.

9. The system according to claim 1, wherein, Impurity water is diverted from the first channel to the fourth channel.

10. The system according to claim 9, wherein, The impurity water is discharged from the impurity water outlet formed by the distal ends of the plurality of the fourth channels.

11. The system according to claim 1, wherein, The three-way bifurcation structure includes a first bifurcation channel that is in fluid communication with the second channel and a second bifurcation channel that is in fluid communication with the third channel.

12. The system according to claim 11, wherein, The angle formed by the first diversion channel and the second diversion channel with respect to the first channel is at least one of the following: 1 to 30 degrees, 30 to 60 degrees, 60 to 90 degrees, 90 to 120 degrees, 120 to 150 degrees, or 150 to 179 degrees.

13. The system according to claim 11, wherein, The first shunt channel and the second shunt channel include widths of at least one of the following: approximately 1 to 10, 10 to 60, 60 to 100, or 100 to 200 micrometers.

14. The system according to claim 1, wherein, The first channel has a width of approximately 200 to 600 micrometers.

15. The system according to claim 14, wherein, The fourth channel has a width of approximately 140 to 500 micrometers.

16. A water purification system, comprising: Multiple filter elements, including: A plurality of first channels extending from a proximal end of the filter sheet toward a distal end of the filter sheet, each of the first channels including a first sidewall and a second sidewall, wherein the first sidewall and the second sidewall include a hydrophilic surface; and Multiple tri-branch structures are provided at the distal end of each of the first channels, each tri-branch structure dividing the first channel into a second channel, a third channel, and a fourth channel, wherein the fourth channel is parallel to the first channel, and wherein the second channel and the third channel extend through the body of the filter. Unfiltered water enters the plurality of first channels of the plurality of filter elements, and purified water is diverted from each first channel to the second and third channels; and A water container for receiving the plurality of filter elements and guiding the unfiltered water to the plurality of first channels of the plurality of filter elements.

17. The system according to claim 16, wherein, The water container supplies the unfiltered water to the plurality of first channels with a pressure head of at least 15 cm to 2 meters.

18. The system of claim 16, further comprising a bottom cover disposed on the bottom of the plurality of filter elements, wherein, The bottom cover includes a cutout that provides an outlet for purified water received from a plurality of second and third channels, wherein the outlet is located outside the body of the water container when the plurality of filter elements are received by the water container.

19. The system of claim 18, further comprising a top cover disposed on top of the plurality of filter elements, wherein, The plurality of filter elements, the bottom cover, and the top cover are anodized to form a filter element by at least one of the following methods: airtight hydrophilic adhesive, titanium sputtering annealing, direct silicon fusion bonding, or hot pressing bonding, and wherein the water container receives the filter element.

20. The system of claim 18, further comprising a top cover disposed on top of the plurality of filter elements, wherein, The plurality of filter elements, the bottom cover, and the top cover are hermetically sealed using hydrophilic adhesives, sputtered titanium annealing, direct silicon fusion bonding, or hot-press bonding.

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