Electrospinning Image Gallery

Curly Polycaprolactone Fibers

This backscattered electron micrograph shows the effect on the microstructure of Polycaprolactone (PCL) electrospun fibers when a low voltage (-5 kV) is used on the collector in a Fluidnatek LE-100. Since the fibers have more attraction towards the collector (when compared to a grounded collector) they have less time to stretch during the process, creating the curly pattern throughout the sample. Fiber-fiber bonding between fibers is also increased as the solvent does not have enough time to fully evaporate.

Close up of Polyacrylonitrile Fibers

Closer look at electrospun polyacrylonitrile (PAN) fibers made using the Fluidnatek LE-50. These PAN fibers have a standard deviation less than 50 nm as they were developed under tight environmental conditions. These results can be obtained all year round when temperature and relative humidity and tightly controlled with the Fluidnatek technology.

Electrospun Polyacrylonitrile Fibers

Electron micrograph of electrospun polyacrylonitrile (PAN) made using the Fluidnatek LE-100. These fibers were collected on top of a polyethylene with carbon black substrate to allow for easy sample removal. PAN fibers are typically used for filtration, energy storage applications and to coat medical devices.

Electrospun Polycaprolactone Fibers

Backscattered electron micrograph of electrospun polycaprolactone (PCL) made using the Fluidnatek LE-500. To achieve reproducibility and fiber consistency, the electrospinning conditions were set to 24 ± 1°C and 40 ± 3%. These randomly oriented fibers offer a pore size around 20 µm to allow for cell infiltration for tissue engineering related applications.

Patterned Alignment of Electrospun Fibers

This SEM image shows electrospun polycaprolactone (PCL) made in a Fluidnatek LE-50 at 1,000 rpm and at a translational needle speed of 20 mm/s and a low voltage of -4 kV. The combination of slow translational speed, along with the high rpm and low voltage, allowed the fibers to be collected with a peculiar wavy pattern with significant amount of fiber-fiber bonding that can increase mechanical properties of the final sample.

Electrospun Nerve Conduit

Microstructure of an electrospun nerve conduit made out of electrospun polylactic acid (PLA) made in the Fluidnatek LE-100. Characteristic features of this sample include the perpendicular aligned PLA fibers on the central portion of the sample (right side of the image) and randomly oriented PLA fibers surrounding the aligned fibers. The packing density of the aligned layers can be controlled with the Fluidnatek technology to fine tune final sample.

Electrospun Polybutylene Succinate

Micrograph of electrospun polybutylene succinate (PBS), a biodegradable polymer with water and carbon dioxide byproducts upon degradation by microorganisms. These plant based fibers were electrospun with the Fluidnatek LE-50 and are currently being used for single use food packaging and related applications.

Beaded PCL fibers

Electron micrograph of biodegradable beaded fibers made out of polycaprolactone (PCL) using the Fluidnatek LE-100 with a 5 mm outside diameter mandrel rotating at 200 rpm. This image was acquired by mixing the signal of the backscatter and secondary electron detectors in a 1:1 ratio. In the past, this type of fiber morphology was thought to be a disadvantage in the electrospinning field. These days the beaded fiber structure is used for drug encapsulation, coat medical devices, increase efficiency of air filtration, among others.

Electrospun Fiberglass

Scanning electron microscope image showing the microstructure of electrospun fiberglass made with a Fluidnatek LE-50. Electrospun fiberglass is being used as a flame retardant material in different applications including textiles. These fibers could also be used as heat dissipation to protect sensitive materials from fire hazards.

Close up of Electrospun Porous Polycaprolactone Microfibers

Electron micrograph of biodegradable porous polycaprolactone (PCL) with a diameter around 10 µm. This image shows a close up onto the porous structure of the electrospun PCL fibers. The nanoscale porosity was achieved thanks to the quick solvent evaporation during the electrospinning process.

Electrospun Porous Polycaprolactone Microfibers

Microstructure of porous polycaprolactone (PCL) fibers with a diameter around 10 µm. These fibers were produced in a single step with the Fluidnatek LE-50 using a single solvent. These large fibers have good elongation properties, making it an ideal material to be used for artificial blood vessels, especially to mimic the tunica media layer of the saphenous vein. The nanoscale porosity was achieved thanks to the quick solvent evaporation during the electrospinning process.

Cross-Sectional Structure of Electrospun PLA

This micrograph shows the cross-section of electrospun polylactide acid (PLA) made using a Spinbox equipment at 1,000 rpm. Thanks to the high glass transition temperature of PLA, the sample preparation to visualize the cross-section only required a simple cut with a scalpel. Other polymers need to be freeze fractured to prevent smearing from happening. Electrospun PLA fibers are typically used for wound healing and drug delivery applications, along with coating medical devices.

Closer look at Patterned Alignment of Electrospun Fibers

SEM image of electrospun polycaprolactone (PCL) made using the Fluidnatek LE-50. This image was acquired with a backscatter electron detector at an accelerating voltage of 5 kV. The microstructure reveals fiber-fiber bonding. This is due to low collector voltage during sample processing. When fibers are attracted faster to the collector, the solvent has less time to evaporate, allowing fibers to be wet and generate fiber-fiber bonding.

Stent coated with electrospun fibers

Coronary artery stent with an outside diameter of 5 mm coated with electrospun polycaprolactone (PCL). This SEM image is a composite of 5 rows and 8 columns stitched automatically to have a representative look at the microstructure of the coated surface. Stents are coated with fibers to make them more biocompatible. The beauty of the electrospinning technique is that it allows stents to be coated with different polymeric materials and drugs can be incorporated to improve patient healing

Electrosprayed Collapsed Polycaprolactone Microparticles

Backscattered electron micrograph of electrosprayed polycaprolactone (PCL) particles made with a Fluidnatek LE-50 and collected onto a liquid reservoir. These electrosprayed particles are characterized by their collapsed structure and the nanoscale porosity, both due to the use of a low boiling point and high vapor pressure solvent, along with their large diameter (>20 µm). These PCL particles can be used for drug delivery applications and to uniformly coat medical devices

Electrosprayed Smooth Polycaprolactone Microparticles

Electron micrograph of electrosprayed polycaprolactone (PCL) microparticles made with a Fluidnatek LE-50. These particles were made with a high boiling point and low vapor pressure solvent allowing them to obtain a smooth and rounded morphology. After collecting onto a liquid reservoir, the media was evaporated, and the PCL particles agglomerated for future experiments

Electrosprayed Rough Polycaprolactone Microparticles

These electrosprayed polycaprolactone (PCL) rough microparticles were made on a single step using a Spinbox equipment and collected onto a flat plate collector covered with aluminum foil. Note the two distinctive surfaces (Janus morphology) on the right particle. Increasing the surface area of a particle, especially without post-processing and at room temperature, can help with drug delivery applications by loading thermal sensitive materials

Electrospun Polycaprolactone Fibers Collected at 0 RPM

Randomly oriented fibers made out of polycaprolactone (PCL) and on top of a 10 cm diameter drum in a Spinbox equipment. These fibers were collected at 0 rpm to study the effect of fiber orientation under the influence of only the rotational speed in the drum collector.

Electrospun Polycaprolactone Fibers Collected at 50 RPM

Randomly oriented fibers made out of polycaprolactone (PCL) and on top of a 10 cm diameter drum in a Spinbox equipment. These fibers were collected at 50 rpm to study the effect of fiber orientation under the influence of only the rotational speed in the drum collector. At this speed the fibers are still randomly oriented throughout the sample structure.

Electrospun Polycaprolactone Fibers Collected at 200 RPM

Randomly oriented fibers made out of polycaprolactone (PCL) and on top of a 10 cm diameter drum in a Spinbox equipment. These fibers were collected at 200 rpm to study the effect of fiber orientation under the influence of only the rotational speed in the drum collector. At 200 rpm the PCL fibers are still randomly oriented throughout the sample structure.

Electrospun Polycaprolactone Fibers Collected at 500 RPM

Randomly oriented fibers made out of polycaprolactone (PCL) and on top of a 10 cm diameter drum in a Spinbox equipment. These fibers were collected at 500 rpm to study the effect of fiber orientation under the influence of only the rotational speed in the drum collector. At 500 rpm the PCL fibers are still randomly oriented, but some initial reorientation can be seen throughout its microstructure.

Electrospun Polycaprolactone Fibers Collected at 1,000 RPM

Randomly oriented fibers made out of polycaprolactone (PCL) and on top of a 10 cm diameter drum in a Spinbox equipment. These fibers were collected at 1,000 rpm to study the effect of fiber orientation under the influence of only the rotational speed in the drum collector. At 1,000 rpm the PCL fibers realign during collection and the pore size of the sample is slightly increasing at the same time.

Electrospun Polycaprolactone Fibers Collected at 1,500 RPM

Randomly oriented fibers made out of polycaprolactone (PCL) and on top of a 10 cm diameter drum in a Spinbox equipment. These fibers were collected at 1,500 rpm to study the effect of fiber orientation under the influence of only the rotational speed in the drum collector. At 1,500 rpm the PCL fibers are realigning towards 90 degrees.

Electrospun Polycaprolactone Fibers Collected at 2,000 RPM

Randomly oriented fibers made out of polycaprolactone (PCL) and on top of a 10 cm diameter drum in a Spinbox equipment. These fibers were collected at 2,000 rpm to study the effect of fiber orientation under the influence of only the rotational speed in the drum collector. At 2,000 rpm the PCL fibers are aligned towards 90 degrees and the fiber diameter has been slightly decreased due to the high linear speed during collection. This orientation is used to increase mechanical properties and biomimic native extracellular matrix of different types of tissue.

Effect of Collector Voltage on Tubular Collectors

Stitched image of 40 scanning electron micrographs of polycaprolactone (PCL) fibers collected on top of a 1 cm diameter rod at 200 rpm and with the collector grounded in a Fluidnatek LE-100 equipment. At 0 kV on the collector a rough microstructural surface is observed due to residual charge, causing fibers to localize in certain areas of the sample, affecting the final porosity of the electrospun material. By using a higher bias this effect will be completely removed and the final sample will contain a smooth surface.

Effect of Collector Speed on Tubular Collectors

Backscattered electron micrograph of polycaprolactone (PCL) fibers collected on top of a 1 cm diameter rod at 200 rpm in a Fluidnatek LE-100 equipment. At 200 rpm, and for large deposition times, a rough microstructural surface is observed that is due to residual charge, causing fibers to localize in certain areas of the sample, affecting the final porosity of the electrospun material. This microstructural effect is removed when using higher linear speeds or when combined with a higher bias at the same rotational speed.

Electrospun Gelatin Fibers

This SEM image shows the microstructure of ribbon-shaped gelatin fibers made out of electrospinning with a Fluidnatek LE-50 and collected onto a rotating drum. The ribbon-shape structure is typically observed when the solvent evaporates fast during the spinning process. The fast evaporation process causes the fibers to collapse and obtain this flattened structure. A rounded morphology can be obtained by optimizing solution properties by using a high boiling point solvent like acetic acid.

Electrospun Nylon 6,6 Fibers

Backscattered electron micrograph of electrospun nylon 6,6 (N66) fibers made with a Fluidnatek LE-500 with a multi-needle system and continuously collected onto a roll-to-roll collector. N66 is a commonly used polyester for air and liquid filtration applications due to its hydrophilicity, good solvent resistance, tailored fiber diameter, pore size tuning and ease of scalability with the electrospinning technology.

Electrospun Nylon Fibers

Micrograph of electrospun Nylon nanofibers made with a Fluidnatek LE-100 and collected onto a flat plate collector. Nylon nanofibers are commonly used for filtration applications, tissue engineering like bone regeneration when incorporated with hydroxyapatite, and medical sutures as they are stronger and durable when compared with silk.

Electrospun Polycaprolactone Fibers Collected at 0 kV

The effect of fiber deposition density and microstructure was studied using electrospun polycaprolactone (PCL) fibers, collecting onto a flat plate collector of a Fluidnatek LE-500 by having all processing parameters constant and only changing the collector voltage. With a grounded collector (0 kV) we can see a low fiber density and large pore size.

Electrospun Polycaprolactone Fibers Collected at -1 kV

The effect of fiber deposition density and microstructure was studied using electrospun polycaprolactone (PCL) fibers, collecting onto a flat plate collector of a Fluidnatek LE-500 by having all processing parameters constant and only changing the collector voltage. With a -1 kV applied in the collector, we can see a denser deposition when compared to the 0 kV sample. All fibers look relatively dry at these processing conditions.

Electrospun Polycaprolactone Fibers Collected at -5 kV

The effect of fiber deposition density and microstructure was studied using electrospun polycaprolactone (PCL) fibers, collecting onto a flat plate collector of a Fluidnatek LE-500 by having all processing parameters constant and only changing the collector voltage. With a -5 kV applied in the collector, we can see a denser deposition when compared to the -1 kV sample. All fibers look relatively dry at these processing conditions.

Electrospun Polycaprolactone Fibers Collected at -10 kV

The effect of fiber deposition density and microstructure was studied using electrospun polycaprolactone (PCL) fibers, collecting onto a flat plate collector of a Fluidnatek LE-500 by having all processing parameters constant and only changing the collector voltage. With a -10 kV applied in the collector, we can see that the fibers are not fully dried as there is more fiber-fiber contact, and the pore size has been reduced.

Closer Look of Electrospun Polycaprolactone Fibers Collected at -10 kV

Backscattered electron micrograph of electrospun polycaprolactone (PCL) fibers, collecting onto a flat plate collector of a Fluidnatek LE-500 with a collector voltage of -10 kV. Fiber-fiber bonding is clearly seen throughout the microstructure. Although typically considered a non-desired defect, these wet fibers can be used to adhere two layers of materials with the electrospinning technique. Dry fibers can be obtained after adhesion by simply changing the collector voltage towards 0 kV.

Electrosprayed Polycaprolactone Microparticles

Electron micrograph of electrosprayed polycaprolactone (PCL) microparticles made with a Fluidnatek LE-50. These particles have a diameter around 4 µm and were collected on top of polyethylene with carbon black to allow ease of removal post-processing. This smooth surface can be made with other types of polymers to obtain dry particles in a single step, encapsulate materials, and increase throughput by scaling up the electrospraying process for industrial production.

Electrosprayed Porous Polycaprolactone Microparticles

This SEM image shows an electrosprayed polycaprolactone (PCL) microparticles made with a Fluidnatek LE-50 using a low boiling point and high vapor pressure solvent. These particles show a characteristic collapsed surface with pores throughout its diameter ranging from a couple microns to the nanoscale size.

Electrospun Nanofibers and Electrosprayed Microparticles

Microstructure of a sample made by combining electrospun polycaprolactone (PCL) nanofibers and electrosprayed PCL microparticles using the Fluidnatek LE-100. Applications like tissue engineering can benefit from combining fibers and particles in a single step and at room temperature conditions to have encapsulated growth factors that can be released at specific times. These types of samples can also be used for drug delivery applications on medical devices.

Electrospun Fibers and Electrosprayed Particles

This SEM image shows the microstructure of polycaprolactone (PCL) nanofibers when combined with PCL electrosprayed particles at the same time in the Fluidnatek LE-100. To achieve this, the sample was collected onto a rotating drum by electrospinning the fibers in a horizontal setup and electrospraying the particles in a vertical setup, both needles pointing towards the same collector.

Electrospun Sub-micron Fibers of PLA

Microstructure of electrospun polylactic acid (PLA) fibers with sub-micron diameter. These fibers were produced in a single step with the Fluidnatek LE-50 using a solvent mixture of dichloromethane and dimethyl formamide solvent. PLA is used in FDA approved medical products, making it an ideal material to be used for artificial blood vessels, covering stent or for wound healing processes.

Electrospun Collagen Fibers

Electrospun collagen fibers using 1,1,1,3,3,3-hexafluoroisopropanol (HFIP) as the solvent. Collagen is commonly used in wound healing applications as it is a polymer found in the in vivo environment. This sample was developed using the Fluidnatek LE-50 and under tight environmental conditions (23°C and 60% relative humidity) to allow for ease of processability.

Electrospun beaded fiberglass

Fiberglass is typically use in applications were durability and heat resistance is a must. These electrospun beaded fibers were made with the Fluidnatek LE-50 using the rotating collector platform to generate a sample of 20 cm x 32 cm.

Electrospun Micro-scale Polycaprolactone Fibers

Microstructure of polycaprolactone (PCL) microfibers with a diameter around 8 µm. These fibers were produced with dichloromethane (DCM). Since DCM has a low boiling point and high vapor pressure, it evaporates fast during sample processing, generating large fibers. The final sample has large pore size, allowing the sample to be an ideal candidate for tissue engineering applications as cells will be able to infiltrate and proliferate in the material

Closer Look at Porous Micron Polycaprolactone Fibers

Upon close inspection, we see a porous structure on these 8 µm polycaprolactone (PCL) fibers. The small porosity allows cells to anchor and proliferate easier. These fibers were made using the Fluidnatek LE-50 using a rotating drum collector of 10 cm in diameter at 200 rpm.

Blended Electrospun Polycaprolactone and Nylon 6,6 Fibers

Electrospinning allows the use of blending materials during sample processing. This image shows electrospun microscale fibers composed of polycaprolactone (PCL) and Nylon 6,6 (N66). Before processing, these two polymers were blended with the same solvent. During processing the final material is a combination of PCL:N66 that will impart properties to fulfill different application needs.

Blended Electrospun Polycaprolactone and Polyethylene Terephthalate Fibers

This microstructure shows microscale fibers of blended polycaprolactone (PCL) and polyethylene terephthalate (PET). The combination of PCL and PET is typically used when mechanical properties on the final structure are needed.

Closer Look of Electrospun Blended Polycaprolactone and Polyethylene Terephthalate Fibers

This SEM image taken on the Phenom Desktop SEM shows the microstructure of blended polycaprolactone and polyethylene terephthalate microfibers. These PCL:PET fibers are also combined when the degradation rate of PCL needs to be fine-tuned by adding a biostable PET, or when PET fibers need to be in combination with a biodegradable polymer like PCL

Post-treated Polycaprolactone:Polyethylene Terephthalate Electrospun Fibers

Post-processing as-spun electrospun fibers is typically done when microstructure or properties of the final sample are needed. This image shows the microstructure changes of PCL:PET fibers when treated with acetone for 5 seconds. At a magnification of 2,500 X the microstructure looks similar to the as-spun PCL:PET fibers.

Closer Look of Post-treated Polycaprolactone:Polyethylene Terephthalate Electrospun Fibers

Upon close inspection we can see smaller pores on the surface of the fibers when the sample is imaged at 5,000 X. This porosity could change microstructure properties, drug release properties, or even cell proliferation depending on application needs

Blended Polycaprolactone and Polyethylene Terephthalate Fibers Post-treated with Acetone

Microstructure of acetone post-treated microfibers of PCL:PET. Imaging at 10,000 X we can clearly see the nanoscale porosity that has appeared on the surface of the electrospun fibers. Depending on the polymer compatibility, blended ratio and interaction during processing, different type of post-processing structures could be obtained and fine tuned based on application needs.

Microscale Polylactic Acid Electrospun Fibers

Microstructure of microscale polylactic acid (PLA) fibers with an average diameter of 6 µm. These fibers were produced in a single step with the Fluidnatek LE-50 using a single solvent. These large fibers have good elongation properties, making it an ideal material to be used for artificial blood vessels, especially to mimic the tunica media layer of the saphenous vein.

Close up of Electrospun Porous Polylactic Acid Microfibers

Electron micrograph of biodegradable porous polylactic acid (PLA) with an average diameter of 6 µm made with dichloromethane (DCM) as the solvent in solution. This image reveals a porous structure of the surface of the electrospun PLA fibers. The nanoscale porosity was achieved thanks to the quick solvent evaporation during the electrospinning process.

Electrospun Nanoscale Nylon 6,6 Fibers with Trapped Pollen

Microstructure of Nylon 6,6 (N66) nanoscale fibers with trapped pollen on its surface. Nylon 6,6 is commonly used for filtration applications. Electrospinning allows the generation of nanoscale N66 fibers allowing for easy mechanical entrapment of particles on filtration media.

Closer Look of Electrospun Nylon 6,6 Fibers with Trapped Pollen

Electrospun micrograph showing trapped pollen on the nanoscale fibers of Nylon 6,6 (N66) made with electrospinning. N66 is an easy to process polymer through the electrospinning technique. It has been used in scale up processes to generate more than 1,000 m2/h of material.

Stitched Image of Electrospun Nylon 6,6 with Trapped Pollen

This image shows an overall look on the filtration media made out of Nylon 6,6 with trapped pollen on its structure. Electrospun fibers allow for mechanical filtration and samples that can be reused when compared to statical filtration media.

Electrospun Thermoplastic Polyurethane Fibers

The microstructure of thermoplastic polyurethane (TPU) fibers generated with the Fluidnatek LE-50 using a mandrel collector of 5 mm in diameter. TPU fibers are commonly used in medical application as it is a flexible polymer with good mechanical properties. The electrospinning technique allows for fine tuning the fiber diameter and pore size to fulfill different application needs.

Closer Look of Electrospun Thermoplastic Polyurethane Fibers

Electron micrograph of electrospun thermoplastic polyurethane (TPU) fibers. This image shows a combination of micron and sub-micron scale TPU fibers made with the electrospinning technique. TPU is a polymer used in medical product currently approved and cleared by the Food and Drug Administration (FDA).

Surgical Mesh Coated with Electrospun Thermoplastic Polyurethane Fibers

Overall view of a surgical mesh coated with electrospun thermoplastic polyurethane (TPU) fibers. TPU fibers were used to coat the surface of the surgical mesh to make it more biocompatible by allowing the structure to resemble the extracellular matrix. By using electrospinning, the addition of fibers can make the surgical mesh more biocompatible and accepted by the body after implantation.

Surgical Mesh Coated with a Thick Layer of Electrospun Thermoplastic Polyurethane Fibers

This stitched SEM image shows the microstructure of TPU fibers when electrospun on top of a surgical mesh for a long time. The ability of electrospinning to coat different substrates with different thickness give the flexibility to obtain desired properties based on application needs.

Surgical Mesh Coated with Electrospun Thermoplastic Polyurethane Fibers

This image shows the back area of the surgical mesh coated with electrospun TPU fibers. Electrospinning has the ability to properly attach electrospun fibers to any type of mesh and prevent delamination. This allows the final sample to not go over post-processing needed with typical techniques used by the scientific community.

Electrospun Fibers made out of Hyaluronic Acid

Microstructure image of electrospun hyaluronic acid (HA), a natural polymer typically used in food packaging, cosmetics, and tissue engineering applications. This image with a magnification of 10,000 X reveals sub-micron fibers. The analysis was performed with a mixture of backscattered and secondary detector at a ratio of 50:50.

Electrospun Polyethylene Oxide Nanoscale Fibers

This image shows the microstructure of electrospun nanoscale polyethylene oxide (PEO) fibers. These fibers were developed with the Fluidnatek LE-50 using a rotating drum of 10 cm in diameter and rotating at 100 rpm. The solvent used for processing PEO was water. To prevent needle clogging or dryness, the environmental conditions were maintained at 28°C and 40% relative humidity.

Electrospun Beaded Polyethylene Terephthalate Fibers

Electron micrograph of electrospun polyethylene terephthalate (PET) beaded fibers. Beaded fibers are usually not desired by the scientific community. Meanwhile, beaded fibers offer advantages like encapsulation ability of different active ingredients or drugs that can be delivered without bursting release. In order to prevent beaded fibers in the final morphology, the easy solution is to increase the concentration of the final solution. This will allow you to obtain only fiber formation without beads.

Electrospun Polyvinylidene fluoride Nanoscale Fibers

This SEM image shows the microstructure of nanoscale electrospun fibers out of polyvinylidene fluoride (PVDF). Nanoscale fibers are commonly developed with the electrospinning technique, and we can develop them with a diameter less than 20 nm depending on solution properties. These fibers were made with the Fluidnatek LE-50 using the rotating drum of 10 cm in diameter and at 50 rpm to obtain randomized morphology.

Electrosprayed Particles on Top of a Non-Woven Material

Microstructure of a non-woven material covered with electrosprayed particles using the Fluidnatek LE-500. Electrospraying can be used to coat different types of materials and surfaces to impart different properties that the native material does not have by itself. As seen in the SEM image, the particles only cover the non-woven material and not the porosity of the structure, opening many possibilities for the coating industry.

Metal Filament Coated with Electrospun Fibers

Electron micrograph of a 200 µm diameter metal wire of coated with electrospun fibers made out of a synthetic polymer and using the Fluidnatek LE-100 BioTubing. The Fluidnatek technology allows to cover samples with diameters less than 1 mm with precise thickness and uniformity. Coating different surfaces allows to impart properties like biocompatibility, drug delivery form the fibers, improve mechanical strength improvement, among others.

Electrospun Nerve Graft

This image SEM image shows a cross-sectional image of an electrospun nerve graft made out of three distinctive layers of poly(lactic acid) fibers. Electrospinning has the innate capability to biomimic different morphologies that are found on native tissue. Artificial nerve grafts are one of the many possibilities of microstructure that can be made with the Fluidnatek technology and the electrospinning technique.

Effect of Negative High Voltage on Polyacrylonitrile Electrospun Fibers

Backscattered electron micrograph of electrospun polyacrylonitrile (PAN) in DMSO made using the Fluidnatek LE-50. The image shows an intended effect of fast attraction to the collector when using a low negative voltage. A low voltage can help prevent delamination between two layers but is always recommended to expose the sample to a vacuum environment to remove residual solvent.

Effect of Negative High voltage on Polyacrylonitrile Electrospun Nanofibers

Microstructure of polyacrylonitrile (PAN) in DMSO using the Fluidnatek LE-50. This image shows the effect of negative voltage when fibers are attracted fast towards the collector. Lower collector high voltage can be used to induce bundles, obtain larger fiber diameter and have residual solvent that will help with adhesion between two layers. Beaded structures are seen as the fiber did not bend and whip enough to stretch the material during collection.

Electrospun Poly(n-Butyl Methacrylate) Microfibers

Backscattered electron micrograph of electrospun poly(n-butyl methacrylate) (PBMA) microfibers generated with the Fluidnatek LE-50. PBMA is a biocompatible polymer used to coat metal stents and control drug delivery on those types of devices. The microstructure of PBMA can be easily tuned with electrospinning to generate nano- or micro-fibers, with different pore size and porosity, based on application needs.

Electrospun Poly(Vinylidene Fluoride-co-Hexafluoropropylene) Fibers

This image shows the microstructure of poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) electrospun fibers made with the Fluidnatek LE-50. PVDF-HFP is a commonly used thermoplastic polymer in applications like medical device and binding for electrodes in lithium-ion batteries. In medical applications, PVDF-HFP is used to prevent blood clotting and inhibit platelet adhesion.

Electrospun Polycaprolactone Fibers on Top of Surgical Mesh

Overall view of a surgical mesh coated with a thin layer of electrospun polycaprolactone (PCL) microfibers. PCL fibers were used to coat the surface of the surgical mesh to make it more biocompatible as the microstructure resembles the extracellular matrix of native tissue. By using electrospinning, the addition of fibers can make the surgical mesh more biomimetic and accepted by the body after implantation.

Thick Layer of Electrospun Polycaprolactone Fibers on Top of Surgical Mesh

This stitched SEM image shows the microstructure of PCL fibers when electrospun on top of a surgical mesh for a long time. The ability of electrospinning to coat different substrates with different thickness gives the flexibility to obtain desired properties based on application needs.

Cross-Sectional SEM Image of Electrospun Tubular Scaffolds

Stitched SEM micrograph showing different electrospun tubular polycaprolactone scaffolds made with the Fluidnatek LE-100 BioTubing. The BioTubing equipment allows to generate tubular structures from less than 1 mm in diameter and up to 20 cm in diameter. These types of samples are commonly used as artificial blood vessels with different polymers, fiber orientations, diameters and even multi-layered structures.

Cross-sectional Microstructure of PCL Fibers made with a 1 mm Mandrel

Backscattered electron micrograph of a tubular structure made out of polycaprolactone (PCL) with the Fluidnatek LE-100 BioTubing. The cross-sectional image was obtained by freeze fracturing PCL with liquid nitrogen. If cut at room temperature, the sample will smear, and the microstructure was not going to remain intact as its glass transition temperature is -60°C.

Cross-sectional Microstructure of PCL Fibers made with a 2 mm Mandrel

This image shows the cross-section of electrospun polycaprolactone fibers collected on a 2 mm diameter rod with the Fluidnatek LE-100 BioTubing. Sample thickness was approximately 150 µm and homogeneous across its diameter and length. Artificial blood vessels up to 40 cm in length can be obtained with the Fluidnatek technology, or longer upon request.

Cross-sectional Microstructure of PCL Fibers made with a 5 mm Mandrel

This SEM micrograph shows the cross-sectional structure of polycaprolactone fibers collected onto a 5 mm diameter rod with the Fluidnatek LE-100 BioTubing. The sample is completely porous and if needed, two materials can be collected at the same time to improve mechanical properties, tune porosity and pore size, or have additives like vascular growth factors.

Micronized Scaffold from Electrospun Nanofibers

Electron micrograph of micronized scaffold electrospun nanofibers made from a natural protein. Electrospun fibers can be engineered to biomimic the human extracellular matrix. By micronizing the electrospun scaffold these micronized nanofibers can be applied to complex or irregular topography for wound healing. This image was acquired by mixing the signal of the backscatter and secondary electron detectors at a 1:1 ratio.

Close up of Micronized Scaffold from Electrospun Nanofibers

This SEM image shows a closer look of micronized electrospun nanofibers made from a natural protein. While the micronized sample has a length less than 150 µm, the fiber diameter is less than 450 nm in diameter. These micronized fibers can be fully engineered and can be applied dry or hydrated based on the targeted tissue.

Stent Coated with Electrospun Fibers

Coronary artery stent coated with electrospun thermoplastic polyurethane (TPU). Electrospinning allows direct deposition onto a metal, or non-metal, mesh to improve biocompatibility of the medical devices. Adhesion and bonding of electrospun fibers onto the mesh can be achieved and will withstand tears during crimping. This process reduces manufacturing cost as it does not need suturing by hand.

Close up of Electrospun Gelatin Ribbon Shaped Fibers

Backscattered electron micrograph of ribbon shaped electrospun fibers made out of gelatin type A from porcine skin. Gelatin fibers are commonly used in the medical field and can be found on products approved, and cleared, by the Food and Drug Administration (FDA). Gelatin from other sources, like fish and bovine, are also processed to generate electrospun fibers or electrosprayed particles.

Silk Fibroin Electrospun Fibers

This SEM image shows the microstructure of electrospun silk fibroin (SF), which is typically used in applications like tissue engineering and drug delivery. Silk fibroin is typically electrospun by using a secondary polymer to makes SF electrospinnable. In this case, polyethylene oxide (PEO) was used as the additive polymer to generate the scaffolding material.

Silk Fibroin Electrospun Fibers with Nanofiber Webbing

Microstructure of electrospun silk fibroin (SF) with nanofibers from webbing. Webbing is a common defect on electrospun fibers that can occur when the processing parameters have not been optimized. This defect is commonly seen when operating at low relative humidities where the polymer solution can evaporate quickly, causing the formation of these nanoscale fibers with diameter below 100 nm.

Electrospun PVDF-HFP with Inorganic Particles

This SEM image shows the microstructure of poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) containing inorganic particles. Electrospinning offers the capability to generate fibrous materials containing different types of additives to improve sample properties based on application needs.

Electrospun PCL with Enhanced Surface Area

This microstructure image shows polycaprolactone (PCL) electrospun fibers with a bumpy structure. This rougher microstructure can be engineered for filtration applications where improvement of filtration capabilities is needed for filters made from nanoscale fibers. This image was obtained from a field of depth over 600 µm on a tilted sample with the aid of a python script using the Phenom Desktop SEM.

Electrospun Yarns from Polyhydroxybutyrate

This stitched image shows the microstructure of two electrospun polyhydroxybutyrate (PHB) based yarns made with the Fluidnatek technology. Yarns made out of electrospinning offer the innate ability to resemble the extracellular matrix, incorporate additives like drugs, generate complex structures from two different types of fibers, or even combine fibers and particles on the same yarn.

Closer up of Electrospun Yarns from Polyhydroxybutyrate

This close up microstructure of the electrospun PHB yarn shows the degree of twist on the final sample. Yarns developed with electrospinning can be used for suture based applications, whether from pure electrospun fibers, or by reinforcing a yarn with nano- or micro-scale fibers to improve mechanical properties needed during the suturing process. Once the yarn process is optimized, more than 30 meters can be developed in one run with our yarn collector.

Polyacrylonitrile Stabilized by Heat Treatment

Microstructure of electrospun polyacrylonitrile (PAN) imaged using a backscatter electron detector with the Phenom Pharos desktop SEM. PAN is commonly used for hot gas filtration applications as it offers good thermal stability and mechanical strength needed. This sample was stabilized at a temperature of 250°C before imaging. Oxidative stabilization is needed prior to the carbonization step.

Carbonized Polyacrylonitrile Nanofibers

This SEM image shows carbonized polyacrylonitrile (CPAN) obtained after heat treatment at temperatures above 1,000°C under inert environment. CPAN has excellent electrical conductivity and offers good mechanical strength needed when used for fuel cell applications. Note the reduction in fiber diameter from its stabilized predecessor while still maintaining a homogeneous diameter post-carbonization.

Electrospun Commercial Medical Products

This image shows some electrospun product that can be generated with the Fluidnatek technology under cGMP and ISO-13485 for medical devices. These include electrospun scaffolding material as a wound dressing, micronized nanofibers, stent covered with nano- or micro-fibers, tubular scaffolds, electrospun yarns, among others.

Electrospun Sample to Improve Wound Healing

Electrospun nanofibrous scaffolding sample for wound dressing applications. It is made out of a natural based protein able to biomimic the extracellular matrix. These types of samples can be made with natural polymers like collagen, gelatin, chitosan and soy based materials. Researchers have also used FDA approved synthetic polymers like polycaprolactone, polylactic acid, and poly(lactic-co-glycolic acid).

Electrospun Micronized Nanofibers

Micronized nanofibers made out of electrospinning can be used for drug delivery or wound healing. They can be injected for direct application of fibers to the intended wound. This type of sample can be sprinkled over complex shaped wounds to improve wound healing. If a drug is loaded on the fibers, the micronized nanofibers can deliver a drug while aiding the wound healing process.

Stent covered Electrospun Polycaprolactone Fibers

Two stents used as medical devices, one composed only of nitinol metal and the second one coated with electrospun fibers. The Fluidnatek technology allows to coat medical devices like stent with electrospun fibers and/or particles. Coating a stent with electrospun fibers allows the device to be biocompatible and its properties can be tuned based on application needs.

Electrospun Sample made with Randomly Oriented Fibers

This stretched sample shows electrospun microfibers made with polycaprolactone (PCL) using the Fluidnatek technology. These electrospun fibers are able to elongate more than 100% and it is thanks to the mechanical properties of PCL when dichloromethane is used as the solvent. Electrospinning is a versatile technique where users can fine tune sample properties based on application needs.

Mandrel Covered with Electrospun Polycaprolactone Containing an Additive

Electrospun blood vessels are one of the many possibilities of electrospun materials that can be generated using the Fluidnatek technology. This image shows a mandrel covered with electrospun polycaprolactone containing red food coloring, which imparts the light red color on the sample. Additives can be easily incorporated in the solution, allowing the final sample to be embedded with them.

Sample Removal from Rotating Mandrel

Tubular electrospun samples can be removed from the mandrel by sliding the sample or cutting it into small sections. The sample shown and made with polycaprolactone containing red food coloring as an additive, was cut to be used for contact angle analysis. This particular sample had a 1 cm inside diameter, but the Fluidnatek technology allows diameters smaller than 1 mm and more than 20 cm based on application needs.

Wettability Analysis on Polycaprolactone with an Additive

Contact angle analysis of an electrospun sample made with polycaprolactone (PCL) and red food coloring as an additive. The addition of the dye did not significantly affected the hydrophobicity of the PCL fibers as it remained with a value higher than 130°. Depending on additives used, the wettability of an electrospun sample can be fine tuned based on application needs.

Wettability Analysis on Hydrophobic Electrospun Polycaprolactone

This image shows the hydrophobic behavior of electrospun polycaprolactone (PCL) under static contact angle analysis using the Attension line. The analysis was done with a water drop of 4 µL and repeated seven times to obtain a representative value of the hydrophobicity of PCL.

Wettability Analysis on Hydrophilic Electrospun Gelatin

Contact angle analysis of an electrospun gelatin made with the Fluidnatek LE-500 under tight environmental conditions. The quick absorption of the water onto the sample is shown in the image. Gelatin is a hydrophilic material and commonly used in tissue engineering applications as it is non-toxic, biocompatible and biodegradable.

Wettability Analysis on Blended Polycaprolactone:Polyethylene Terephthalate Electrospun Sample

Closer look at the wettability on blended polycaprolactone and polyethylene terephthalate fibers at a ratio of 90:10 by weight. Contact angle analysis can be used to quickly evaluate if residual solvent is present. If polar solvents were used, and not evaporated properly, the sample would behave as hydrophilic, allowing to quickly optimize the electrospinning process to minimize residual solvent.

Rotating Drum Covered with Randomly Oriented Electrospun Polyhydroxybutyrate Fibers

Randomly oriented electrospun polyhydroxybutyrate fibers collected on a rotating drum with 10 cm diameter and 30 cm in length. The drum was homogeneously coated thanks to the needle translation capabilities the Fluidnatek technology offers. If needle translation is not used, the sample homogeneity will not be present, compromising results and batch-to-batch reproducibility.

Effect of Negative High Voltage on Rotating Mandrels

Electrospun fibers are typically deposited onto ground surfaces. Control over collector voltage opens many possibilities on sample properties. This image shows the effect of negative voltage on mandrel collectors. At 0 kV (top rod) the sample is spread out with a bumpy surface due to residual charge. As the voltage decreases (-5 kV, middle; -15 kV, lower) deposition area is reduced with a smoother surface.

Effect of Negative High Voltage on a Flat Plate Collector

This image shows the effect of negative high voltage on a flat collector. At -10 kV (left) the sample deposition area is around 4 cm, with the area increasing to 7 cm when using -4 kV (right). The Fluidnatek technology allows control over the collector voltage (positive and/or negative) which aids in sample collection and prevents delamination between layers, a crucial property for medical devices.

Y-Shaped Collector Covered with Electrospun Polyurethane Fibers

Electrospun polyurethane fibers collected onto a Y-shaped collector with the Fluidnatek LE-100. This image is an example of the many possibilities of types of collectors that can be used to collect fibers, or particles, with atypical morphologies.

Effect of Dwelling Time to Improve Thickness on Sample Edges

This image shows electrospun polylactic acid fibers collected onto a 10 cm drum collector. The edges are intentionally thicker than the rest of the sample. This demonstrates one capability of the Fluidnatek technology to improve sample homogeneity. Dwelling on the edges can be controlled from a couple milliseconds to 10 seconds, improving thickness morphology on the final sample.

Funnel of Electrospun Fibers to Generate Surgical Sutures

Electrospun yarns are becoming popular within the scientific community as they can be used to generate biodegradable and biocompatible sutures with different drugs. The Fluidnatek technology allows the use of yarn collectors where one or multiple types of materials can be collected simultaneously under tight environmental conditions, allowing for reproducibility needed for FDA clearance and GMP production.

Electrospun Yarns Made out of Poly(3-Hydroxybutyrate-co-3-Hydroxyvalerate)

This image shows an electrospun yarn made with poly(3-hydroxybutyrate-co-3-hydroxyvalerate) using the yarn collector. More than 10 meters of yarn can be continuously collected with the Fluidnatek technology. Not only yarns can be generated, but any type of filament can be reinforced with electrospun fibers or particles using the same collector.

Electrospun Tubular Samples with Different Inside Diameters

The Fluidnatek technology allows collection of multiple types of samples, one of them being hollow tubular structures. These types of samples are commonly used as artificial blood vessels for tissue engineering applications, or to incorporate stents with electrospun fibers. This image compares a penny with tubular scaffolds from 5, 3, 2, 1 and 0.5 mm inside diameter (right to left).

Linear Injector with 20 Simultaneous Needles

Multi-needle system of 20 simultaneous needles processing polyacrylonitrile. This image clearly shows the effect of charge repulsion on the needles at each corner. Due to charge repulsion, the electrospun jet at the edges is deflected and tends to deposit outside of the collector. This behavior is not desired, which is why the Fluidnatek technology offers field deflectors to prevent this from happening.

Linear Injector with 20 Simultaneous Needles Using Field Deflectors

This image shows the effect of field deflectors at the edges of a linear multi-needle system. Thanks to the field deflector (metal plate on the corners), the same charge applied to the needle is transferred to the edges. This allows for all electrospun jets to travel towards the collector, minimizing the loss of fibers or particles during sample collection, a crucial option when using expensive materials.

Robotic Arm with Movable Needle to Coat Non-Symmetrical Samples

Non-symmetrical, or atypical samples are commonly seen on medical devices that are implanted in the body. The Fluidnatek technology allows the implementation of a robotic arm with a movable needle with more than three axes of rotation. This gives the user the flexibility to coat complex surfaces not able to be covered with other commercially available instrumentation.

Robotic Arm with Movable Collector to Coat Challenging Samples

The Fluidnatek technology can be implemented with a robotic arm to rotate collectors with more than three axes of rotation. This allows the user to maintain the needle in one position and move the collector at different rotational speeds (200 to 2,000 rpm) along with complete freedom to rotate the robotic arm. The future of medical electrospinning to coat medical devices under clean conditions is here!

Slit Injector for Needle-Less Electrospinning and Electrospraying

Needle-less electrospinning lacks control over flow rate and solution concentration can change over time when low boiling point solvents are used. The Fluidnatek equipment offers the slit injector, an innovative needle-less technology that maintains the solution concentration the same all the time. It allows users to know the flow rate during sample processing, along with the possibility to do gas assisted processing.

Medical Device Manufacturing under Sterile and Clean Conditions

Medical electrospinning is becoming a hot topic for medical industries working with tissue engineering and medical devices. The Fluidnatek technology already offers a solution with the LE-50 ProSterile. This system allows the production of electrospun and electrosprayed samples under sterile and clean (ISO-5) conditions, along with the capability to vacuum a sample to remove possible residual solvents.

Fluidnatek Industrial Facilities for Electrospinning Production

The Bioinicia team had the first GMP facility for electrospun fiber production using the Fluidnatek technology. This image shows three of the Fluidnatek HT equipment at the Fluidnatek facilities in Valencia, Spain. This technology is used for the generation of filtration products, pure cosmetics, along with other commercially available products manufactured under ISO-13485 requirements.

Monitoring all Electrospun Parameters with the High Definition Process Data Hub

Industrial scale production requires rigorous monitoring of all processing parameters to evaluate stability over time. All Fluidnatek equipment can be implemented with the high definition process data hub where more than 20 process parameters and equipment signals are monitored. This powerful Industry 4.0 software is a unique tool for anyone looking for smart manufacturing and enhanced productivity.

Electrospun Patch for Wrinkle Correction Being Applied to the Eye Contour

This image shows the anti-wrinkle patch before the main ingredients are released onto the skin. The formula is of 100% natural origin and consists only of active ingredients hydroxytyrosol (olive extract), hyaluronic acid, pullulan and vegetable elastin. The lifting effect is achieved just 3 seconds after the main ingredients from the electrospun sample are released onto the skin. Wrinkle Correction Electrospun Sample Being Applied to the Eye Contour.

Rolls of Electrospun Material Collected on Top of a Non-Woven Substrate

With industrial scale production comes the need for large roll-to-roll substrates. This image shows three rolls of 1.6 meters in width and more than 1 meter in diameter, allowing the collection of electrospun fibers over a 24/7 process.

Polymer Solution Reservoir for Industrial Scale Electrospun Production

To scale up a process towards industrial generation it is mandatory to have a large solution reservoir that allows the equipment to process 24/7. The Fluidnatek HT allows the use of up to 60 L but with the capability to refill the reservoir once needed to allow the 24/7 production, something currently done with the HT equipment.

Multiple Linear Injectors for Industrial Electrospun Production

This image shows eleven linear multi-needle injectors inside the Fluidnatek HT for industrial scale and increased production throughput. Needle-based allows for a tight control over fiber generation by keeping the concentration of the solution the same at all times, along with properly knowing the flow rate during production, something not seen with other technologies.

Industrial Scale Needle-Based Electrospinning Equipment

Electrospinning is typically seen as a non-scalable technique as most of the scientific community uses home-built units. This image shows the Fluidnatek HT, an industrial scale electrospinning equipment currently used to generate multiple commercial products. The HT can use more than 5,000 simultaneous needles and generate products with a width of 1.6 meters over roll-to-roll capacity.

Closer Look at Super Aligned Electrospun Polyhydroxybutyrate Fibers

Close up image on the final sample of polyhydroxybutyrate (PHB) super aligned fibers. These fibers were collected on a rotating drum with a 10 cm diameter rotating at 1,000 rpm with the Fluidnatek LE-100. Samples with all fibers oriented around the same degree are considered super aligned. This alignment can help improve cell to proliferation as cells tend to migrate faster with aligned fibers.

Electrospun Polyhydroxybutyrate Sample Made with Random Fibers

Scaffolding material made out of randomly oriented polyhydroxybutyrate (PHB) fibers made with the Fluidnatek technology. PHB is a biodegradable polymer considered eco-friendly and adaptable with multiple technologies. This polymer is typically brittle and rigid, but thanks to the electrospinning technique, material properties can be fine-tuned to make flexible and biodegradable products.

Carbonization Steps of Electrospun Polyacrylonitrile Nanofibers

Electrospun polyacrylonitrile (PAN) is commonly used to generate carbon nanofibers by means of carbonization under inert environment. This image shows changes in sample morphology at different stages of carbonization. Electrospun PAN, with the typical as-spun white color is shown on the left, an intermediate carbonization process is shown in the middle, and carbonized PAN is shown on the right.

Pilot Scale Production with Needle-Less Technology

This image shows the use of two 50 cm long slit injectors processing polyvinylidene fluoride (PVDF) fibers with the needle-less technology. With one slit injector of 50 cm, we have observed values of 394 grams by square meter (gsm) deposited onto the roll-to-roll collector. These values can increased as the Fluidnatek technology allows up to four simultaneous slit injectors in the LE-500 equipment.

Polyacrylonitrile Electrospinning using 60 Simultaneous Needles

Image showing the collection of polyacrylonitrile (PAN) electrospun fibers onto a flat collector with a roll-to-roll system. Although only two linear injectors of 30 needles each (60 needles total) are being used for this sample, the Fluidnatek LE-500 allows the use of up to 370 needles to increase sample throughput and scale up your process.

Eight Meters of Electrospun Polyacrylonitrile Fibers

One of our Nanoscience Analytical members showcasing the scale up polyacrylonitrile (PAN) electrospun sample he achieved using the Fluidnatek LE-500. The process was scaled up from 1 to 120 needles using a roll-to-roll collector. This eight meter sample was made in under an hour with a PAN fiber diameter of 263 ± 1.4 nm.

Electrospun Gelatin Based Scaffold

Scaffolding material from electrospun fibers based out of gelatin type A from porcine skin. Gelatin is a natural polymer similar to collagen and commonly used to generate fibers based out of electrospinning due to its biocompatibility, biodegradability and ease to dissolve in different solvents. Gelatin has been blended with other polymers like polycaprolactone (PCL) and polyethylene terephthalate (PET) to improve mechanical properties needed for implantation.

Electrospun Scaffolds from Various Polymers

This image shows electrospun scaffolding material made from eight different polymers using the Fluidnatek technology. This fiber based samples were made from poly(L-lactide-co--caprolactone) (PLCL), polycaprolactone (PCL), poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP), polylactic acid (PLA), polyethylene oxide (PEO) fibers, poly(azanediyladipoylazanediylhexane-1,6-diyl) (nylon 6,6), gelatin (Gel) and polyvinyl Alcohol (PVA).

Electrospun Tubular Scaffolds

The Fluidnatek technology allows its users to generate tubular samples with inside diameter as low as 250 µm. This image shows different types of electrospun blood vessels with diameters less than 1 mm. The pore size and porosity on these samples can be fine-tuned by post-processing them with heat treatment.

Stent Covered with Polyurethane

Stents can be coated with electrospun fibers to improve their biocompatibility and resemble the in vivo environment found in the human body. This image shows a stent with an inside diameter of 1 cm coated with thermoplastic polyurethane (TPU). If coated properly these electrospun coated stents can withstand tears that can occur by crimping or after expanded to maintain in place during implantation.

Rotating Drum Collector

Electrospun fibers or electrosprayed particles are deposited in different collectors based on application needs. The rotating drum collector is the most popular collector as it offers the capability to fine-tune the microstructure to generate randomly oriented, semi-aligned, aligned or super aligned fibers. The Fluidnatek technology can be implemented with rotating collectors ranging from 250 µm up to 30 cm in diameter.

Electrospun Based FFP2 Filtration Mask

Proveil is an FFP2 filtration media commercially available and developed by Bioinicia using the Fluidnatek technology. It is composed of three layers with the middle active based of nanofibers containing a virucidal to inactivate viruses upon contact with the fibers. As opposed to electrostatic based filtration, these masks offer high mechanical filtration capacity thanks to their nanoscale pores and large surface area where larger particles cannot penetrate.