Filtration Applications Research Articles

Airflow resistance analysis of wire screens used in waste heat recovery systems

Wire screens are widely used in electronics, refrigeration, insect screens, food processing, filtration, oil refinery, agricultural, and other applications. For instance, these wire screens are used as heat exchange materials in regenerators due to higher surface area density. Heat transmission can typically be enhanced by increasing the surface area density of wire screens, however flow obstruction is a possibility. As a result, this wire screen analysis is necessary not only to estimate the heat transfer rate but also to assess the airflow obstruction. This extensive study investigates the role of wire screens in a wind tunnel on the different velocities of air moving through them in order to compute the pressure drop. Six wire screens were examined as part of this investigation, and the experimental results were utilised to derive the coefficients of second order polynomials (a,b, and c). Permeability and inertial factor were calculated using this second order polynomial and Forchheimer’s equations. Second-order polynomial equations were found to be the best fit for the permeability versus porosity ratio and the inertial factor versus porosity ratio.

Blend of Fibres to Improve the Mechanical Properties of Needle-Punched Nonwovens for PM2.5 Air Filtration

This research investigated the innovative synthesis achieved through blending five distinct fibres (Polyacrylonitrile (PAN), Polyester (PET), Polylactic acid (PLA), Polypropylene (PP), and Polyphenylene sulfide (PPS)) in the production of needle-punched nonwoven fabrics tailored for air filtration applications. The study investigated the effects of needle-punched nonwovens made with up to five fibres on the physical and mechanical properties, addressing a gap in existing literature. The method involved manual and machine opening, blending, and carding of fibre s, followed by producing three samples with different web arrangements (cross laid web, parallel laid web, and pre needled parallel lad web). The study employed standard test methods to characterize physical and mechanical properties. Results indicated that web arrangement and pre-needling significantly influenced various properties, with cross and parallel-laid web arrangements having minimal impact on thickness and bursting stretch. The parallel arrangement, whether pre-needled or not, showed no significant effect on GSM, fabric density, bursting strength, tear strength, abrasion resistance, and filtration efficiency. The highest abrasion resistance, lower pressure drop, highest fabric stiffness, moderate tensile strength, and higher bursting strength were observed in a cross-web arrangement. This study contributed valuable insights into the intricate interplay of fibre composition, web arrangement, and pre-needling in the design of advanced needle-punched nonwoven fabrics for air filtration. The findings provided a nuanced understanding of how these factors collectively impact the mechanical and physical characteristics of the material, paving the way for enhanced efficiency, durability, and versatility in air filtration applications.

Polyelectrolyte-Surfactant Complex Nanofibrous Membranes for Antibacterial Applications.

Polyelectrolyte-surfactant complexes (PESCs) have garnered significant attention due to their extensive range of biological and industrial applications. Most present applications are predominantly used in liquid or emulsion states, which limits their efficacy in solid material-based applications. Herein, pre-hydrolyzed polyacrylonitrile (HPAN) and quaternary ammonium salts (QAS) are employed to produce PESC electrospun membranes via electrospinning. The formation process of PESCs in a solution is observed. The results show that the degree of PAN hydrolysis and the varying alkyl chain lengths of surfactants affect the rate of PESC formation. Moreover, PESCs/PCL hybrid electrospun membranes are fabricated, and their antibacterial activities against both Gram-negative Escherichia coli (E. coli) and Gram-positive Staphylococcus aureus (S. aureus) are investigated. The resulting electrospun membranes exhibit high bactericidal efficacy, which enables them to serve as candidates for future biomedical and filtration applications.

Robust three-dimensional bioinspired honeycomb structured ultra-elastic aerogels for high-temperature cascade filtration applications

High-temperature particulate matter (PM), commonly produced by daily power generation, industrial smokestacks, and vehicle exhaust emissions, causes a significant risk to public health and environmental sustainability. The current strategy for solving these problems is to utilize adsorption filtration technology. In this work, we successfully constructed a bioinspired honeycomb structured aerogel with nano/micron fiber-reinforced polyimide gradient by using two strategies of fiber-reinforced filler and stepwise directional freezing technique. It overcomes the high shrinkage of polyimide aerogel and exhibits super elastic recovery performance without damage after 100 compression cycles at 50% strain, as well as high flame-retardancy and low thermal conductivity (32.14 mW m−1 K−1). Meanwhile, it shows excellent air filtration efficiency of about 97% and pressure drop of about 90 Pa after 50 cycles, as well as an excellent oil/organic solvent absorption performance and recoverability. In principle, the gradient structure with gradual change shows the “medium pore-small pore” cascade interception effect in the direction of airflow velocity propagation, which successfully achieves the selective and precise interception of polydisperse particles and the stratified accumulation of particles. It further significantly extends the filter service life and provides new insights into the upgrade of new high-temperature filters with significant research implications.

Efficient strategies for engineering high-permeance SiC ceramic membranes for gas/solid filtration: Prefilling method

The trade-off between gas permeance and filtration accuracy in SiC ceramic membranes has constrained their utilization in gas/solid filtration. Herein, a polyvinyl butyraldehyde (PVB) solution was introduced as a prefilling layer to impede membrane particles from penetrating the macroporous SiC support (average pore size: 23 μm). The PVB layer could be removed postsintering, thereby producing a ceramic membrane devoid of any intermediate layer, which showed great potential in enhancing the gas permeance. Initially, the PVB concentration was optimized to ensure membrane integrity and strong adhesion between the support and separation layer. Thereafter, suitable dispersants and drying conditions were investigated in detail. The resultant asymmetric SiC membranes fabricated under these optimized conditions had a thickness ranging between 50 and 60 μm. These membranes demonstrated exceptional gas permeance, varying from 71.1 to 178.1 m3 m−2 h−1 kPa−1 by tuning the membrane pore size from 1.02 to 3.03 μm. Additionally, the membranes achieved 99.94 % dust rejection for particles approximately 0.3 μm in size. When compared to traditional ceramic membranes with several intermediate layers, the prefilling approach employed herein circumvents the ceramic intermediate layer. This method resolves the mismatch between particle sizes of the ceramic support and the membrane layer, offering an effective strategy for developing high-permeance SiC membranes suited for gas/solid filtration applications.

Development of biodegradable nanofiber filters based on surface-modified cellulose nanofibers with graphene oxide for high removal of airborne particulate matter

Airborne particulate matter is a pressing environmental and public health concern globally. This study aimed to develop sustainable filtration materials from cellulose nanofibers (CNFs) modified with graphene oxide (GO) to capture fine particulates from air effectively. CNFs were extracted from α-cellulose via mechanical grinding and modified with 0.5–1.5 wt% GO solution by ultrasonication to produce CNF-GO nanocomposites. These were freeze-dried into highly porous, lightweight aerogels for air filtration applications. Fourier transform infrared spectroscopy (FT-IR) confirmed GO incorporation through hydroxyl group interactions. Field emission scanning electron microscopy (FE-SEM) revealed a porous 3D network with reduced porosity after GO addition due to pore blocking. X-ray diffraction analysis showed the cellulose I crystal structure was retained after modification. Brunauer-Emmett-Teller (BET) measurements indicated increased density but decreased surface area and pore volume with GO loading. The thermogravimetric analysis demonstrated improved thermal stability with GO incorporation due to oxidative reactions and a barrier effect. The particulate absorption efficiency markedly increased from 86.37 % to 99.98 % for CNFs modified with 1.5 wt% GO due to the high surface area, surface oxygen functionalities, and nanoplatelet morphology of GO. The nanofiber filters with 1.5 wt% GO exhibited a maximum absorption efficiency of 99.98 % and a quality factor of 0.0912 Pa−1. Although GO reduced biodegradability, substantial degradation occurred under soil conditions. Overall, the sustainable, high-efficiency CNF-GO air filters developed in this work demonstrate immense promise for controlling air pollution and protecting human health.

Cellulose nanofibers, nanocrystals, and bacterial nanocellulose: Fabrication, characterization, and their most recent applications

AbstractIn nature, cellulose is present in fibrillar structures with alternative crystalline and amorphous fragments. The application of various chemical treatments (acid hydrolysis, enzymolysis, and oxidation) could lead to the extraction and purification of crystalline compartments in the form of cellulose nanocrystals. On the other hand, applying harsh mechanical treatments (milling, ultrasonication, high‐pressure processing, grinding, microfluidization, etc.) could result in the degradation of cellulose macrostructures into nano‐fibrillated segments without depletion of the amorphous fractions. These structures are called cellulose nanofibers. Bacterial nanocelluloses (BNCs) are another nanostructure of cellulose that is generated through the bottom–up technique. BNCs are the purest forms of cellulose nanostructures (CNSs). Hitherto, various spectroscopy and microscopy characterization techniques have been developed for in‐depth investigation of CNSs. The valuable information obtained via such instrumental techniques has opened windows on new horizons for the application of CNSs in novel realms. Nowadays, CNSs have found a seat in biomedical, packaging, emulsification, water filtration, and textile applications. In this review, after describing various forms of CNSs and their fabrication methods, the most recent techniques that have been utilized for the characterization of these structures plus their current application in different realms are comprehensively overviewed.

Self-Cross-Linking of MXene-Intercalated Graphene Oxide Membranes with Antiswelling Properties for Dye and Salt Rejection.

Membrane-based water purification is poised to play an important role in tackling the potable water crisis for safe and clean water access for the general population. Several studies have focused on near two-dimensional membranes for this purpose, which is based on an ion rejection technique. However, membrane swelling in these materials has emerged as a significant challenge because it leads to the loss of function. Herein, we report a self-cross-linked MXene-intercalated graphene oxide (GO) membrane that retains ion and dye rejection properties because the physical cross-linking interaction between Ti-O-Ti and neighboring nanosheets effectively suppresses the swelling of the membrane. In addition to the associative Ti-O-Ti bonds, C-O-C, O=C-O, and C-OH bonds are also formed, which are important for inhibiting the swelling of the membrane. To ensure the longevity of these membranes in a service context, they were subjected to heat pressurization and subsequent thermal annealing. The membrane subjected to this novel processing history exhibits minimal swelling upon immersion in solutions and retains function, rejecting salt and dyes over a wide range of salt and dye concentrations. Furthermore, these membranes successfully rejected dye and salt over a period of 72 h without a degradation of function, suggesting that these membranes have the requisite durability for water filtration applications.

Increasing particle concentration enhances particle penetration depth but slows down liquid imbibition in thin fibrous filters

The transport of particles within thin, porous media is a complex process which received growing attention due to its applications in filtration, printing and microfluidics devices. The effect of particles on liquid imbibition and particle clogging can reduce the performance and lifetime of these applications. However, these processes are still not clearly understood and are challenging to investigate. The goal of this study is to increase our understanding about the effect of particle concentration on the imbibition process in thin fibrous membrane filters. In this study, an Ultra-Fast Imaging NMR method is used to study the particle penetration inside nylon membrane filters for particle suspensions with varying particle concentrations (C0). The measurements revealed that increasing the particle concentration increases the particle penetration depth S(t) as governed by a Langmuir isotherm given by S(t)=l(t)(1+κC0)/1+κ(C0+Cb,m), with Cb,m the bound particles and κ the binding constant. Secondly, in droplet penetration, particles slow down liquid penetration in a Darcy like manner where effect on viscosity (η) and surface tension (σ) determine the penetration speed rather than changes within permeability (K0). The final liquid front (l), scaled according to l2∝σt/η. The particle penetration depths were verified using scanning electron microscopy images.

Boundary value problems of degenerate integro-differential equations on the boundary of the region with application in filtration

Boundary value problems of degenerate integro-differential equations on the boundary of the region with application in filtration

Exploring the Mpemba effect: a universal ice pressing enables porous ceramics.

Piezoceramics with global porosity and local compaction are highly desired to exploit the combination of mechanical and electrical properties. However, achieving such a functional combination is challenging because of the lack of techniques for applying uniform pressure inside porous ceramic green parts. Nature provides many examples of generating strong forces inside the macro and micro channels via the state transformation of water. Inspired by these phenomena, we present a technique of "ice and fire", that is, water freezing (ice pressing) and high-temperature sintering (fire), to produce ideal porous piezoceramics. We introduce a new compaction method called the "ice pressing method", which manipulates liquid phase transition for compaction. This method has several advantages, including uniform pressure distribution, a wide pressure range, high effectiveness, and selective freezing. It can generate an ultrahigh pressure of up to 180 MPa on the piezoceramic green skeletons in minutes while retaining their functional pore structures. By exploiting the Mpemba phenomenon, we further accelerate the compaction procedure by 11%. The first ice-pressed and second fire-consolidated lead zirconate titanate (PZT) ceramics are highly densified and exhibit an outstanding piezoelectric response (d33 = 531 pC N-1), comparable to conventional pressed bulk counterparts and 10-20 times higher than those of unpressed materials. The novel ice pressing method breaks the limitation of lacking a compaction technique for porous ceramics. The versatile and effective ice pressing method is a green and low-cost route promoting applications in sensors, acoustics, water filtration, catalyst substrates, and energy harvesting.

Proceedings of the 2023 Viral Clearance Symposium, Session 7: Up- and Downstream Virus Retentive Filtration.

Session 7 of the 2023 Viral Clearance Symposium reviewed progresses in virus retentive filtrations applied to both upstream and downstream processing. Upstream topics included investigations and applications of media viral filtration for upstream cell culture viral risk mitigation. Downstream topics included evaluation of viral breakthrough in continuous processing using surrogate particles and demonstration of extensive viral filtration cycling with flow interruptions and long duration in connected process. Reuse of viral filters with proposed procedures was successfully demonstrated amid the supply chain challenge encountered during the pandemic. Discussions and additional considerations for the topics were also provided.

ENHANCED MECHANICAL AND THERMAL PROPERTIES OF ELECTROSPUN CELLULOSE ACETATE FIBER MEMBRANES INCORPORATING PAHAE NATURAL ZEOLITE

In recent decades, fiber membranes have garnered significant attention and found numerous applications across various fields. This work used the electrospinning method to create fiber membranes with cellulose acetate (CA) as a primary polymer material. The characteristics of the fiber membrane, such as mechanical and thermal properties, were investigated by incorporating Pahae Natural Zeolite (PNZ) microparticles into the CA matrix. The fiber membranes' mechanical properties are improved by adding PNZ to the CA matrix, and the CA/PNZ 10% exhibits the maximum tensile strength of 0.97 MPa and elongation at a break of 4.52%. Meanwhile, incorporating PNZ filler into CA fiber membranes significantly enhances their thermal stability. This improvement is attributed to the formation of hydrogen bonds between CA and PNZ, as evidenced by the increasing residue values with higher PNZ content. Specifically, the residue of pure CA membrane fiber is 13.46%, which increases to 44.06% for CA/PNZ 15% fiber membranes. These favorable thermal and mechanical properties of the fiber membranes indicate the promising potential of CA/PNZ based membranes for filtration applications.

Predicting micropollutant removal through nanopore-sized membranes using several machine-learning approaches based on feature engineering.

Predicting the efficacy of micropollutant separation through functionalized membranes is an arduous endeavor. The challenge stems from the complex interactions between the physicochemical properties of the micropollutants and the basic principles underlying membrane filtration. This study aimed to compare the effectiveness of a modest dataset on various machine learning tools (ML) tools in predicting micropollutant removal efficiency for functionalized reverse osmosis (RO) and nanofiltration (NF) membranes. The inherent attributes of both the micropollutants and the membranes are utilized as input factors. The chosen ML tools are supervised algorithm (adaptive network-based fuzzy inference system (NF), linear regression framework (linear regression (LR)), stepwise linear regression (SLR) and multivariate linear regression (MVR)), and unsupervised algorithm (support vector machine (SVM) and ensemble boosted tree (BT)). The feature engineering and parametric dependency analysis revealed that characteristics of micropollutants, such as maximum projection diameter (MaxP), minimal projection diameter (MinP), molecular weight (MW), and compound size (CS), exhibited a notably positive impact on the correlation with removal efficiency. Model combination with key variables demonstrated high prediction accuracy in both supervised and unsupervised ML for micropollutant removal efficiency. An NF-grid partitioning (NF-GP) model achieved the highest accuracy with an R 2 value of 0.965, accompanied by low error metrics, specifically an RMSE and MAE of 3.65. It is owed to the handling of the complex spatial and temporal aspects of micropollutant data through division into consistent subsets facilitating improved identification of rejection efficiency and relationships. The inclusion of inputs with both negative and positive correlations introduces variability, amplifies the system responsiveness, and impedes the precision of predictive models. This study identified key micropollutant properties, including MaxP, MinP, MW, and CS, as crucial factors for efficient micropollutant rejection during real-time filtration applications. It also allowed the design of pore size of self-prepared membranes for the enhanced separation of micropollutants from wastewater.

Increased hydrophilicity of lignin-derivable vs. bisphenol-based polysulfones for potential water filtration applications.

The functionality inherent in lignin-derivable aromatics (e.g., polar methoxy groups) can provide a potential opportunity to improve the hydrophilicity of polysulfones (PSfs) without the need for the additional processing steps and harsh reagents/conditions that are typically used in conventional PSf modifications. As determined herein, lignin-derivable PSfs without any post-polymerization modification exhibited higher hydrophilicity than comparable petroleum-based PSfs (commercial/laboratory-synthesized) and also demonstrated similar hydrophilicity to functionalized BPA-PSfs reported in the literature. Importantly, the lignin-derivable PSfs displayed improved thermal properties relative to functionalized BPA-PSfs in the literature, and the thermal properties of these bio-derivable PSfs were close to those of common non-functionalized PSfs. In particular, the glass transition temperature (T g) and degradation temperature of 5% weight loss (T d5%) of lignin-derivable PSfs (T g ∼165-170 °C, T d5% ∼400-425 °C) were significantly higher than those of typical functionalized BPA-PSfs in the literature (T g ∼110-160 °C, T d5% ∼240-260 °C) and close to those of unmodified, commercial/laboratory-synthesized BPA-/bisphenol F-PSfs (T g ∼180-185 °C, T d5% ∼420-510 °C).

Exploration of ferrate (VI) pretreatment and ultrasonication combined with gravity-driven membrane filtration for shale gas wastewater treatment

Gravity-driven membrane (GDM) filtration has gained attention as a promising technology for the decentralized treatment of wastewater. However, one major limitation of GDM filtration is its relatively low permeate flux. In this work, we investigated the application of GDM filtration, combined with ferrate (VI) pretreatment and ultrasonication, for the shale gas wastewater (SGW) treatment, and evaluated their respective impacts on the GDM performance. The results of our study revealed that ultrasonication played a significant role in enhancing the flux of GDM filtration, with an observed increase of 265%. This improvement can be attributed to the effective removal of pollutants from the membrane surface and the reduction of the fouling layer thickness caused by ultrasonication. Compared to a GDM alone, ferrate (VI) pretreatment could notably change the microbial community structure and reduce the extracellular polymeric substances accumulation, which may be linked with an enhancement in stable flux. Ferrate (VI) pretreatment selectively enriched particular microorganisms in SGW, which might perform a role in specific organics degradation. These findings provide valuable insights and suggestions for enhancing the overall performance of GDM systems in wastewater treatment. Notably, the ultrasonically enhanced GDM system, which confers the characteristics of simple operation, low energy supply and no chemical pollution, has great application potential in wastewater treatment.

An efficient atmospheric pollution control using hierarchical porous nanofibers containing zeolitic-imidazolate-frameworks and hydroxyapatite nanoparticles

Air pollution due to contaminants such as particulate matter (PM) and bacteria has become a global atmospheric pollution issue. Identifying effective methods for removing PM and other contaminants such as bacteria is an important challenge, and several efforts are being made to resolve it. In this study, we introduced a polystyrene (PS) hierarchical porous nanofiber (HAP/ZIF-8 @PS HPNF) containing a zeolitic imidazolate framework (ZIF-8) and hydroxyapatite (HAP) for PM (PM2.5, PM10) filtration and antibacterial applications. HAP/ZIF-8 @PS HPNF was manufactured by electrospinning of ZIF-8, which has a synergistic effect on the adsorption of PM and HAP that have antibacterial properties. The modified nanofibers improved the filtration performance and antibacterial activity by adsorbing PM (efficiency = 96.68% for PM2.5 and 96.98% for PM10) and reducing microbial populations (S. aureus and E. coli.). Thus, the well-dispersed ZIF-8 and HAP on the nanofibers, the multifunctional nanofibers are appropriate for use in environments with harmful PM as well as bacteria.

Enhancing filtration flux and antifouling performance of PVDF membrane constructed from semi-interpenetrating network and block copolymers

Organic fouling causes the filtration property and serve life decrease of the PVDF membrane and is the challenge for filtration applications. Therefore, it is an urgency desire to construct a PVDF membrane with good filtration and antifouling for researchers. To this end, a based PVDF and poly(N-isopropyl acrylamide)(PNIPA) semi-interpenetrating network polymer was synthesized and used as membrane matrix for preparing semi-interpenetrating network/block copolymers blend membrane. The membrane composition, structure and performance were systematically characterized and investigated by FTIR spectrum, XPS, SEM, contact angle instrument and the other experimental techniques etc. Results indicate that the prepared membrane contains PVDF, PNIPA and block copolymer poly(ethylene oxide)-b-poly(propylene oxide)-b- poly(ethylene oxide) (F127) components, shows a porous cross section comprising a thin top surface layer with small pores, a finger-shape lower layer and a sponge-shape pore bottom layer. When the membrane are used for the filtration of bovine serum albumin(BSA) in aqueous solution at 25 ℃, the rejection can exceed 95.0% at a high flux of 307 L/(m2·h·bar). Simply raising filtration temperature to 60 °C, the flux can reach 606 L/(m2·h·bar) while the rejection barely changes, significantly improving the filtration ability of the membrane. Furthermore, the flux can recover above 93% of the original value after a BSA filtration and a subsequent water washing. Undoubtedly, the prepared membrane displays great potential for filtering BSA aqueous solution and the reason can be ascribed to the synergy between PNIPA and F127 of the membrane.

Enhancing the Performance of Electrospun Nanofiber Membranes in Water and Wastewater Treatment Processes Using Omniphobic Surface Modification

The necessity for advantageous advancements in filtering technology has resulted in limited attention towards emerging materials, specifically nanofiber membranes, for water purification. The issue of organic material and the collection of residual organics in wastewater is a significant challenge since existing treatments like coagulation/flocculation and chlorine treatment have proven insufficient in achieving satisfactory outcomes. Further treatment and disposal steps are required for the additional amount of sludge produced by these methods. The field of nanotechnology has remarkable promise in filtration applications owing to its capacity to fabricate materials with exact structural control to meet specific needs. Membrane distillation (MD) has emerged as a potentially viable method for treating industrial wastewater. However, the existing hydrophobic MD membranes encounter substantial challenges related to wetting, mostly caused by the presence of pollutants often found in wastewater. This work presents a novel approach for the production of a Poly Vinylidene Fluoride - Hexa Fluoro Propylene Electrospun Nanofiber Membrane (PVF-HFP-ENM) that exhibits enhanced resistance to wetting by reduced surface-tension materials. The PVF-HFP-ENM membrane, which possesses an inherent re-entrant structure, has been fluorinated using 1H, 1H, 2H, 2H-Per Fluoro Decyl Trichlorosilane (PFDT) by Vapor Deposition (VD) without the need for surface activation. The fluorinated membrane had exceptional surface omniphobicity, as evidenced by its high contact angles with water and ethanol, measuring 148±0.4° and 120 ± 0.8°, respectively. The fluorinated membrane exhibited exceptional stability regarding omniphobicity and mechanical qualities, even when subjected to extreme circumstances such as ultrasonic disinfection, boiling water, and acidic and base exposure. The present work focuses on utilizing ENM in the context of industrial wastewater treatment and the alteration of nanomembranes to mitigate clogging problems and enhance the efficiency of wastewater treatment processes.

Simulation and Analysis of Anodized Aluminum Oxide Membrane Degradation.

Microelectromechanical systems (MEMS)-based filter with microchannels enables the removal of various microorganisms, including viruses and bacteria, from fluids. Membranes with porous channels can be used as filtration interfaces in MEMS hemofilters or mini-dialyzers. The main problems associated with the filtration process are optimization of membrane geometry and fouling. A nanoporous aluminum oxide membrane was fabricated using an optimized two-step anodization process. Computational strength modeling and analysis of the membrane with specified parameters were performed using the ANSYS structural module. A fuzzy simulation was performed for the numerical analysis of flux through the membrane. The membrane was then incorporated with the prototype for successive filtration. The fluid flux and permeation analysis of the filtration process have been studied. Scanning electron microscope (SEM) micrographs of membranes have been obtained before and after the filtration cycles. The SEM results indicate membrane fouling after multiple cycles, and thus the flux is affected. This type of fabricated membrane and setup are suitable for the separation and purification of various fluids. However, after several filtration cycles, the membrane was degraded. It requires a prolonged chemical cleaning. High-density water has been used for filtration purposes, so this MEMS-based filter can also be used as a mini-dialyzer and hemofilter in various applications for filtration. Such a demonstration also opens up a new strategy for maximizing filtration efficiency and reducing energy costs for the filtration process by using a layered membrane setup.