ELECTROSPINNING APPARATUS AND METHOD FOR FORMING ALIGNED FIBRES

Abstract

A spinning apparatus (1) for forming aligned fibres, the apparatus (1) comprises a nozzle (12) for ejecting material (P) for forming fibres from a tip thereof, an electrode (14A, 14B), a substrate (S) for receiving fibres (NF) thereon, and first and second electrically insulating members (15A, 15B), wherein the tip of the nozzle (12) is located between the first and the second electrically insulating members (15A, 15B).

Claims

1. A spinning apparatus for forming aligned fibres, the apparatus comprising a nozzle for ejecting material for forming fibres from a tip thereof, an electrode, a substrate for receiving fibres thereon, and first and second electrically insulating members, wherein the tip of the nozzle is located between the first and the second electrically insulating members.

2. A spinning apparatus according to claim 1, wherein the substrate comprises or is formed from an electrically insulative material.

3. (canceled)

4. (canceled)

5. A spinning apparatus according to claim 1, wherein the substrate extends between the first and second electrically insulative member.

6. A spinning apparatus according to claim 1, wherein the first electrically insulating member and the second electrically insulating member are integrally formed or wherein the first electrically insulating member and the second electrically insulating member are separate, distinct components.

7. A spinning apparatus according to claim 1, wherein each of the first electrically insulating member and second electrically insulating comprise a first, e.g. lower, portion and a second, e.g. upper, portion, the first portions of the first and second electrically insulating members are located adjacent or proximate the substrate, the second portions of each of the first and second electrically insulating members extend away from the respective first portions in a direction which is non-pararllel and non-perpendicular to the substrate.

8. A spinning apparatus according to claim 7, wherein the angle created between each of the first and second electrically insulating members with the plane of the substrate is between 25 to 55.

9. A spinning apparatus according to claim 1, wherein the electrically insulating material is formed from, or comprises, a dielectric material.

10. A spinning apparatus according to preceding claim 1, wherein the first electrically insulating material and/or second electrically insulating material and/or the substrate is formed from or comprises one or more of polyurethane, polytetrafluoroethylene (PTFE), and glass.

11. A spinning apparatus according to claim 1, wherein the at least one electrode is selected from a flat, grounded electrode, and a disc-shaped electrode.

12. A spinning apparatus according to claim 1, comprising a first and second grounded plate electrode.

13. A spinning apparatus according to claim 12, wherein each of the first and second electrically insulating members are located adjacent or proximate a respective one of the first and second grounded plate electrodes.

14. A spinning apparatus according to claim 13, wherein the substrate extends between first and second grounded plate electrodes.

15. A spinning apparatus according to claim 1, further comprising a feed reel comprising a length of substrate located upstream of the at least one electrode.

16. A spinning apparatus according to claim 1, further comprising an exhaust or take-up reel being located downstream of the at least one electrode.

17. (canceled)

18. A spinning apparatus according to claim 1, further comprising at least one more spinning apparatus.

19. A method of forming aligned nanofibers, the method comprising providing at least one electrode, locating a first and second electrically insulating member in facing relations, locating a substrate that extends between the first and second electrically insulating members, locating the tip of the nozzle between the first and the second electrically insulating members, applying an electric field between a nozzle and the at least one electrode and depositing aligned nanofibers on a substrate.

20. A method according to claim 19, further comprising positioning the first and second electrically insulating members to be non-parallel and non-perpendicular to the plane of the substrate.

21. A method according to claim 19, comprising moving the substrate with respect to the at least one electrode.

22. A method according to claim 21, wherein the method comprises translationally and/or rotationally moving the substrate.

23. A method of claims 20, wherein the substrate is an endless belt.

24. (canceled)

Description

[0091] Embodiments of the invention will now be described by way of example only with reference to the accompanying drawings in which:

[0092] FIG. 1A is an electrospinning apparatus, according to a first embodiment of the invention;

[0093] FIG. 1B is a side elevation of an insulating member and an electrode, according to the embodiment of the invention shown in FIG. 1A;

[0094] FIG. 2 is an electrospinning apparatus, according to a second embodiment of the invention;

[0095] FIG. 3A is a side elevation of an electrospinning apparatus, according to a third embodiment of the invention;

[0096] FIG. 3B is an image of the electrospinning apparatus of FIG. 3B showing the dimensions of the electrode;

[0097] FIG. 4 is an image of a nozzle for use in the electrospinning apparatus of the invention;

[0098] FIG. 5 is an electrospinning apparatus, according to a further embodiment of the invention;

[0099] FIG. 6 is an electrospinning apparatus, according to a yet further embodiment of the invention;

[0100] FIG. 7 is a photograph of a substrate comprising an aligned nanofibre mat, according to an Example of the invention;

[0101] FIGS. 8A to 8E are SEM images of substrate comprising aligned fibres, which were fabricated according to Examples of the invention;

[0102] FIGS. 9A and 9B are SEM micrographs of substrate comprising aligned fibres at 0 and 90°, according to Examples of the invention; and

[0103] FIG. 10 is a micrograph showing highly aligned and multi-layered nanofibres at different angles produced using the apparatus of FIG. 6.

[0104] Referring now to FIG. 1A, there is shown an electrospinning apparatus 1, according to a first embodiment of the invention. The electrospinning apparatus 1 comprises a dispensing unit 1A and a platform 1B.

[0105] The dispensing unit 1A comprises a reservoir 10, a syringe 11, and a nozzle 12. The reservoir 10 comprises an electrospinning material in the form of a precursor P for the formation of nanofibres NF. In this embodiment, the syringe 11 comprises a screw driven 5 mL syringe for controlling the volume of precursor P dispensed over a specified period of time.

[0106] The platform 1B comprises a base 13, a first electrode 14A, a second electrode 14B, and an insulating member 15. In this embodiment, the insulating member 15 comprises a first insulating member 15A, a second insulating member 15B, interconnected by a joining portion 15C, such that the first insulating member 15A, the joining portion 15C, and the second insulating member 15B form a unitary U-shaped member.

[0107] In this embodiment, the insulating member 15 is formed from a foamed polyurethane sheet.

[0108] The first electrode 14A and the second electrode 14B are grounded plate electrodes, which are io upstanding from the base 13 of the platform 1B in a parallel configuration and in facing relations. In this embodiment, the base 13 is formed from plastic, and the first and second electrodes 14A and 14B are formed from copper, although in alternative embodiments, other suitable materials may be used such as aluminium.

[0109] is The first insulating member 15A and the second insulating member 15B are also upstanding from the base 13 of the platform 1B. The first insulating member 15A is located adjacent the first electrode 14A and the second insulating member 15B is located adjacent the second electrode 14B. The joining portion 15C of the insulating member is located adjacent to, and parallel to, the base B. The first and second insulating members 15A, 15B are located in facing relations, and in-between the first and second electrodes 14A, 14B, such that the first and second insulating members 15A, 15B are located between the first and second electrodes 14A, 14B.

[0110] A substrate S is located on the electrospinning apparatus 1. The substrate S extends longitudinally between the first and second insulating members 15A, 15B, on the joining portion 15C of the insulating member 15, and in parallel to the base 13 of the platform 1B. In this embodiment, the substrate S is formed from paper. It is to be understood that the substrate S is optional, and the aligned nanofibres ANF may be deposited on the insulating member 15 instead.

[0111] Referring also to FIG. 1B, there is shown a side elevation of highlighted section C of the electrospinning apparatus 1 shown in FIG. 1A. The first electrode 14A and the second electrode 14B are parallel, in facing relations, and are substantially perpendicular to the base 13 of the platform 1B.

[0112] The first insulating member 15A is located adjacent or proximate the first electrode 14A such that an internal angle Al is created therebetween. The second insulating member 15B is located adjacent or proximate the second electrode 14B such that an internal angle A2 is created therebetween. In this embodiment, the angle A1 and the angle A2 are substantially equal. In this embodiment, A1=A2=35 to 45°, e.g. 40°.

[0113] The dimensions and geometry of the electrospinning apparatus 1 are shown in FIGS. 1A and 1B. There is shown the height h and width w of the first insulating member 15A. The first and second insulating members 15A, 15B are equal in size and have the same dimensions.

[0114] The distanced between the first electrode 14A and the second electrode 14B is shown in FIG. 1B. There is also shown the width w′ and the height h′ of the first electrode 14A. The first and second electrode 14A, 14B are equal in size and have the same dimensions.

[0115] There is further shown in FIG. 1A the height h″ of the tip of the nozzle 12 from the platform 1 B, i.e. the distance between the tip of the nozzle 12 and the platform 1 B.

[0116] In this particular embodiment, the dimensions of each of the first and second electrode 14A, 14B are 100 mm in width w′, 14 mm in height h′, and 3 mm thick. The distanced between the first electrode 14A and the second electrode 14B is preferably between 15 to 35 mm.

[0117] The first and second insulating members 14A, 14B are formed from polyurethane foam. In this embodiment, the first and second insulating members 14A, 14B are between 0.1 mm to 7 mm thick, for example, between 0.25 mm to 5 mm thick.

[0118] The height h″ of the tip of the nozzle 12 from the platform 1B may be between 4 to 13 mm.

[0119] Preferably, the height h of the first and/or second insulating member 15A, 15B is greater than or equal to the height h″ of the tip of the nozzle 12 from the platform 1 B. It has been surprisingly found that greater alignment of nanofibres ANF may be obtained using this configuration of the apparatus

[0120] It is understood that the dimensions of the electrospinning apparatus of the invention are not absolute, and the function of the invention is dependent on the geometric relationships between the components, such that the components, e.g. the electrode(s), the first and second insulating members, may be scaled up in size or down in size to obtain smaller or larger apparatus that functions in the same way.

[0121] In use, the first and second electrode 14A, 14B of the platform 1B are energised by applying a potential difference between a nozzle 12 and the first and second electrodes 14A, 14B.

[0122] The dispensing unit 1A of the electrospinning apparatus 1 dispenses the precursor P from the reservoir 10 and through the syringe 11. The precursor P passes through the nozzle 12 to form fibres, e.g. nanofibres NF.

[0123] The precursor L may be any suitable electrospinning material, for example, in this embodiment the precursor L is 15% PVP (poly(vinyl pyrrolidone) in ethanol.

[0124] The nanofibres NF are formed by ejection of the precursor P from the nozzle 12 into the atmosphere, where, the solvent of the precursor P evaporates to form continuous nanofibres NF.

[0125] The nanofibres NF align on the substrate S to form continuous aligned nanofibres ANF. Interaction of the nanofibres NF with the electric field that is formed between the nozzle 12 and the first and second electrodes 14A, 14B causes the nanofibres NF to deposit onto the substrate S to produce aligned nanofibers ANF. The aligned nanofibres ANF are aligned in parallel with the first and second electrodes 14A, 14B, and longitudinally along the substrate S.

[0126] It has been shown in the prior art that, in the absence of the insulating member 15, i.e. the first and second insulating members 15A and 15B, the nanofibres NF align to be perpendicular to the first and second electrode 14A, 14B (e.g. see supra).

[0127] Without wishing to be bound by theory, it is thought that the insulating members 15A, 15B influences or modifies the electric field so that the electrospun fibres are aligned in parallel with the first and second plate electrodes 14A, 14B to create a highly aligned fibre mat. The insulating members 15A, 15B interfere with the line of sight between the nozzle 12 and the first and second plate electrodes 14A, 14B, and it is thought that this controls the substantially longitudinal alignment of the aligned nanofibres ANF. The angled first and second insulating members 15A, 15B mitigate or reduce the deposition of nanofibres that are aligned perpendicular with respect to the length of the substrate S and/or the first and second electrodes 14A, 14B. It has been found that when the first and second insulating members 15A, 15B are aligned in parallel, a greater quantity of nanofibres are deposited perpendicularly to the length of the substrate S.

[0128] Referring now to FIG. 2, there is shown an electrospinning apparatus 2 according to a second embodiment of the invention. The references for like features that have previously been described in FIG. 1 are designated with a prime (′) and will not be described further.

[0129] The electrospinning apparatus 2 comprises a first insulating member 16A and second insulating member 16B in place of the insulating member 15 of FIG. 1. In this embodiment, the first and second insulating members 16A, 16B, are separate and are not joined by a joining portion.

[0130] The first insulating member 16A and second insulating member 16B of the electrospinning apparatus 2 function in a like-manner to the insulating member 15 shown in FIG. 1, to produce a fibre mat on the substrate S2 comprising the aligned nanofibres ANF′.

[0131] The electrospinning apparatus 2 further comprises a first end 2A, located upstream of the platform 1B′, i.e. in use, before receipt of the aligned nanofibres ANF′ onto the substrate S2, and a second end 2B, located downstream of the platform 1B′, i.e. in use, after receipt of the aligned nanofibres ANF′ onto the substrate S2.

[0132] The electrospinning apparatus 2 further comprises a feed reel (not shown) located at the first end 2A of the electrospinning apparatus 2, and an exhaust reel (not shown) located at the second end 2B of the electrospinning apparatus 2.

[0133] The feed reel (not shown) is a spool, onto which is wound a length of the substrate S2 that is free from the aligned nanofibres ANF′. In use, the feed reel (not shown) is configured to supply a length of the substrate S2 from the first end 2A of the electrospinning apparatus 2, to the platform 1B′ for receipt of aligned nanofibres ANF′.

[0134] The exhaust reel (not shown) is a spool, onto which a length of the substrate S2 in receipt of aligned nanofibres ANF′ may be wound. In use, the exhaust reel (not shown) is configured to take-up the substrate S2 from the platform 1B′ at the second end 2B of the electrospinning apparatus 2.

[0135] In this embodiment, the feed reel (not shown) and the exhaust reel (not shown) are rotationally driven. In use, the substrate S2 runs, in a running direction RD (shown by the arrows labelled RD in FIG. 2) from the feed reel (not shown) at the first end 2A, through the platform 1B′ of the electrospinning apparatus 2, i.e. in between both of the first and second electrodes 14A′, 14B′, and the first and second insulating members 16A, 16B; to the second end 2B and onto the exhaust reel (not shown).

[0136] During the electrospinning process, the nanofibres NF′ are aligned and deposited onto a section of the substrate S2 located on the platform 1B′ to produce aligned nanofibres ANF′. The feed reel (not shown) and the exhaust reel (not shown) work in concert to run the substrate S2 in a running direction RD through the platform 1B′ of the electrospinning apparatus 2 to constantly renew the section of the substrate S2 that receives the aligned nanofibres ANF′. The substrate S2 in receipt of aligned nanofibres ANF′ is then wound onto, and may be stored on, the exhaust reel (not shown).

[0137] In this way, a fibre mat containing aligned nanofibres ANF′ of any desired length may be fabricated, the only limitation being the length of substrate S2 that is provided to the electrospinning apparatus 2.

[0138] Advantageously, the substrate S2 may be a material for use in the final product comprising the aligned nanofibres ANF′. For example, the substrate S2 may be a glass fibre sheet for use in a composite material, e.g. a reinforced composite panel.

[0139] Alternatively, the substrate S2 may be a sacrificial substrate. In this case, the aligned nanofibres ANF′ may be removed after the electrospinning process is complete, and affixed to an appropriate secondary substrate.

[0140] Referring now to FIG. 3A, there is shown a side elevation of an electrospinning apparatus 3 according to a third embodiment of the invention.

[0141] The electrospinning apparatus 3 is analogous to the electrospinning apparatus 1 of the first embodiment of the invention (shown in FIGS. 1A and 1B), and differs only in that the electrodes 14A, 14B have been replaced with a flat plate electrode 34. It is understood that the electrospinning apparatus 3 comprises all other analogous features such as a dispensing unit, although this is not shown or described further.

[0142] The electrospinning apparatus comprises a platform 3B. In this case, the platform 3B comprises a flat plate electrode 34 and an insulating member 35.

[0143] In this embodiment, the insulating member 35 comprises a first insulating member 35A, a second insulating member 35B, interconnected by a joining portion 35C to form a unitary U-shaped member. In this embodiment, the insulating member 35 is formed from a foamed polyurethane sheet.

[0144] In this embodiment, the electrode 34 is formed from copper.

[0145] The first insulating member 35A and the second insulating member 35B each upstand from the flat plate electrode 34 of the platform 1 B. The flat plate electrode 34 is spaced approximately 1 cm from the joining portion 35C of the insulating member 35.

[0146] A substrate S3 is located on the electrospinning apparatus 3 in the plane labelled as X. The substrate S3 extends longitudinally between the first and second insulating members 35A, 35B, on the joining portion 15C of the insulating member 15, and in parallel to the flat plate electrode 34 of the platform 3B. In other embodiments, the first insulating member 35A and the second insulating member 35B may be distinct and absent a joining portion 35C. In this case, the substrate S3 may be located directly on, and parallel to, the flat plate electrode 34.

[0147] In the geometry shown in FIG. 3A, each of the first and second electrically insulating members 35A, 35B creates an angle A3, A4 of greater than 0 and less than 90° with the plane X of the substrate and/or the flat plate electrode 34. In this embodiment, the angle A3 is equal to A4, each of which are equal to 40°.

[0148] The electrospinning apparatus 3 functions in an analogous manner to that described for the electrospinning apparatus of FIGS. 1A and 1B such that nanofibres align on the substrate S3 to form continuous aligned nanofibres, which are aligned in parallel with the first and second insulating members 35A, 35B, and longitudinally along the substrate S3.

[0149] It is understood that the electrospinning apparatus 3 may further comprise a feed reel (not shown) is located at a first end (not shown) of the electrospinning apparatus 3, and an exhaust reel (not shown) located at a second end 2B (not shown) the electrospinning apparatus 3 such that a fibre mat containing aligned nanofibres of any desired length may be fabricated, in an analogous manner to that shown in and described for FIG. 2.

[0150] Referring also to FIG. 3B, there is shown an image of the electrospinning apparatus 3 of FIG. 3A. There is shown the dimensions of the flat plate electrode 34; the width w3 and the length L.

[0151] In this particular embodiment, the dimensions of the flat plate electrode 34 are 100 mm in length L, 65 mm in width w3, and 0.3 mm in thickness.

[0152] The first and second insulating members 34A, 34B are formed from polyurethane foam. In this embodiment, the first and second insulating members 34A, 34B are between 0.1 mm to 7 mm thick, for example, between 0.25 mm to 5 mm thick.

[0153] The minimum width of the flat plate electrode 34 is the width of the substrate S3. There is no upper limit for the width of the flat plate electrode 34.

[0154] Without wishing to be bound by theory, it is thought that the insulating members 35A, 35B influences or modifies the electric field so that the electrospun fibres are aligned in parallel with the flat plate electrode 34 to create a highly aligned fibre mat. The insulating members 35A, 35B interfere with the line of sight between the nozzle (not shown) and the flat plate electrode 34 such that the spun fibre is influenced by the electric field only at the terminal ends of the insulating members 35A, 35B. In this way, the spun fibres oscillate back and forth along the substrate S3 and it is thought that this controls the substantially longitudinal alignment of the aligned nanofibres ANF.

[0155] Referring now to FIG. 3C, there is shown the electrospinning apparatus 3 of FIGS. 3A and 3B. There is further shown the nozzle 32 in relation to the first and second insulating members 35A, 35B, and the substrate S3.

[0156] In a preferred embodiment, the tip of the nozzle 32 is below the plane Y of uppermost edge of the first and second insulating members 35A, 35B, as is shown in FIG. 3C.

[0157] The height h3 of the tip of the nozzle 32 from the platform 3B may be between 5 to 17 cm, for example, 5 to 15 cm.

[0158] Preferably, the substrate S3 is located between the first and second insulating members 35A, 35B ata height from the flat plate electrode 34 of no more than h3, i.e. below the upper edge of the first and second insulating members 35A, 35B.

[0159] It is understood that the dimensions of the electrospinning apparatus of the invention are not absolute, and the function of the invention is dependent on the geometric relationships between the components, such that the components, e.g. the electrode(s), the first and second insulating members, may be scaled up in size or down in size to obtain smaller or larger apparatus with the same function.

[0160] It is preferable that the dielectric constant of the substrate, e.g. substrate S, S2, S3, is higher than the material from which the first and second insulating members, e.g. 15A, 15B, 35A, 35B, are fabricated.

[0161] Referring now to FIG. 4, there is shown an image 4 of a custom-made glass nozzle 40 for use in electrospinning apparatus of the invention. The custom-made glass nozzle 40 has an outer diameter of 397 micrometres and an inner diameter of 166 micrometres.

[0162] Referring now to FIG. 5, there is shown an electrospinning apparatus 5 according to a further embodiment of the invention.

[0163] The electrospinning apparatus 5 comprises a disc-shaped electrode 54, a first insulating member 55A, and a second insulating member 55B. A substrate S5 is located in between the first insulating member 55A, and the second insulating member 55B.

[0164] The electrospinning apparatus 5 is analogous to the electrospinning apparatus 1 of FIGS. 1A and 1B, and also the electrospinning apparatus 3 of FIG. 3A to 3C, which differs only in that the electrode comprises a circular, disc-shaped electrode 54. It is understood that the electrospinning apparatus 5 comprises all other analogous features such as a dispensing unit, although this is not shown or described further.

[0165] Advantageously, the disc-shaped electrode 54 is rotatable. In this way, the disc-shaped electrode 54 may be cleaned by rotation, e.g. to remove unwanted and/or misaligned and/or randomly aligned nanofibre deposition on the edges of the disc-shaped electrode 54. For example, the apparatus 5 may comprise a cleaning means, e.g. a brush or a wipe, so that the upper surface of the disc-shaped electrode 54 may be cleaned during rotation of the disc-shaped electrode 54 to remove unwanted nanofibre deposition.

[0166] Referring now to FIG. 6, there is shown an apparatus 6 according to a yet further embodiment of is the invention. The apparatus 6 comprises three separate electrospinning apparatus 5a, 5b, 5c of FIG. 5, each of which function to deposit aligned nanofibres ANF onto a substrate S6.

[0167] The apparatus 6 is analogous to that shown in FIG. 2, in that the apparatus 6 further comprises a feed reel (not shown) located at the first end 6A of the substrate S6, and an exhaust reel (not shown) located at the second end 6B of the substrate S6. The feed reel and exhaust reel function in a like-manner to than described for FIG. 2 in that substrate comprising aligned fibres may be fabricated of infinite length.

[0168] Each of the three separate electrospinning apparatus 5a, 5b, 5c is positioned at a different angle with respect to one another such that the deposited aligned nanofibres on the substrate may be aligned at different angles. The angles of alignment are shown as 0° (5a), 90° (5b), and 45° (5c) with respect to the longitudinal direction of the substrate S6.

[0169] In this way, it is possible to fabricate substrates comprising multiple layers of fibres, each of which are aligned in a different direction, i.e. a different angle with respect to that of the longitudinal direction of the substrate S6. Therefore, stacked layers of aligned nanofibres on a substrate may be fabricated without the need for lamination and/or a separate, further manufacturing step.

[0170] To further exemplify the invention, reference is also made to the following non-limiting Examples.

EXAMPLES

[0171] Referring now to FIG. 7, there is shown a photograph of a substrate comprising aligned nanofibres, according to Example 1 of the invention, which was fabricated using the apparatus shown in FIG. 6 according to the invention.

[0172] Referring now to FIGS. 8A to 8E, there is shown SEM images of aligned nanofibres on a substrate, according to Example 2 of the invention.

[0173] The aligned nanofibre mat of Example 2 was produced using the electrospinning apparatus shown in FIG. 3B.

[0174] The aligned fibre mats of Example 1 and Example 2 were both produced using the following parameters: [0175] Needle to substrate distance: 75 mm [0176] Working potential: 7.5 kV [0177] Feeding rate: 0.2 ml/h [0178] U/V shaped dielectric material: PTFE sheet [0179] U/V shaped dielectric dimension: [0180] Height: 75.5 mm [0181] Length: 100 mm [0182] Angle: 37° [0183] Thickness: 1 mm [0184] Electrode dimension: 65*0.3*80 mm (flat plate electrode) [0185] Substrate material: Crafting papers with 0.15 mm thick [0186] Average fibre diameter: 1 μm

[0187] The material used was PAN (Mw=230 k 14 wt. % in DMSO).

[0188] It should be noted that DMF (dimethylformamide) and/or DMAc (dimethylacetamide) may be used in place of DMSO.

[0189] Referring now to FIGS. 9A and 9B, there is shown SEM images of aligned PAN fibres on a substrate, according to Example 3 of the invention. The aligned nanofibre mat of Example 3 was produced using the electrospinning apparatus shown in FIG. 3B and FIG. 6 using the following parameters: [0190] Needle to substrate distance: 70 mm [0191] Working potential: 6.5 kV [0192] Feeding rate: 0.2 ml/h [0193] U/V shaped dielectric material: PTFE sheet [0194] U/V shaped dielectric dimension: [0195] Height: 70.5 mm [0196] Length: 100 mm [0197] Angle: 37° [0198] Thickness: 1 mm [0199] Electrode dimension: 65*0.3*80 mm (flat plate electrode) [0200] Substrate material: Kitchen baking papers, 0.25 mm thick [0201] Fibres formed had an average fibre diameter of 0.5 μm

[0202] The material used was PAN (Mw=150 k 10 wt. % in DMSO).

[0203] There SEM images show layers of aligned fibres; the first (base) layer aligned at 0′ and the second (top) layer aligned at 90°.

[0204] Referring now to FIG. 10, there is shown a micrograph showing highly aligned and multi-layered nanofibres at different angles produced using the apparatus of FIG. 6. The micrograph shows a high-density of nanofibres aligned and successively overlaid at different angles of −45°, +45° and 0°. This demonstrates how the substrate may be rotated as desired to change the angle of the aligned and electro-spun fibres.

[0205] Advantageously, the electrospinning apparatus according to the invention provides a facile and inexpensive means to allow the width and length of the substrate, and therefore the width and length of the aligned fibre mat, to be varied in a facile manner. For example, the distance between the electrodes may be altered and varied to deposit aligned nanofibres onto any width of substrate, to fabricate fibre mats of any suitable width.

[0206] More advantageously, a substrate of any given length may be used and continuously run through the apparatus of the present invention to provide a continuously aligned fibre mat.

[0207] Additionally, substrates comprising layers of fibres may be fabricated, for example, substrates comprising layers of aligned fibres and/or substrates comprising layers of aligned fibres in which at least one layer is aligned in a different direction (i.e. at a different angle) to another, different layer, and/or layers of aligned fibres in which at least one layer consists of aligned fibres and another, different layer consists of random fibres.

[0208] It will be appreciated by those skilled in the art that several variations to the aforementioned embodiments are envisaged without departing from the scope of the invention. For example, the dimensions of the electrodes, electrically insulating members, nozzle height and dimensions provided herein are examples only and may be altered accordingly.

[0209] It will also be appreciated by those skilled in the art that any number of combinations of the aforementioned features and/or those shown in the appended drawings provide clear advantages over the prior art and are therefore within the scope of the invention described herein.