Recycled polymer waste to volumetric triboelectric energy harvesters

Abstract

Disclosed herein are laminate compositions comprising a plurality of fibres, triboelectric generators comprising generators comprising said laminate compositions, substrates and articles comprising said laminate compositions or triboelectric generators. Also disclosed herein are methods of manufacturing the laminate compositions, and uses thereof for electricity generation.

Description

RECYCLED POLYMER WASTE TO VOLUMETRIC TRIBOELECTRIC ENERGY HARVESTERSCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] The present application claims priority from Australian Provisional Patent Application No 2024902508 filed on 12 August 2024, the contents of which are incorporated herein by reference in their entirety.TECHNICAL FIELD

[0002] The present disclosure relates to laminate compositions, triboelectric generators comprising generators comprising said laminate compositions, substrates and articles comprising said laminate compositions or triboelectric generators, methods of manufacture thereof, and methods and uses thereof for electricity generation.BACKGROUND

[0003] There is an increasing interest in energy harvesting technologies capable of converting energy from sources such as wind, vibration or human body motion into electrical energy. Triboelectric generators (TENGs) have emerged as exceptionally promising devices for converting low frequency, ambient movement, or vibration, into electricity. Triboelectric generators typically comprise two polymer surfaces that periodically undergo contact separation, resulting in one polymer surface gaining a positive charge, and one polymer surface gaining a negative charge.

[0004] Historically, it was believed that the two polymer surfaces within a triboelectric generator needed to have different polymer chemistries. Although contact electrification between same-material has been observed, same-material triboelectric generators have suffered from low energy outputs compared to convention triboelectric generators (e.g. different polymer materials) due to a comparative lack of driving force for charge separation. This lower energy output has resulted in same-material triboelectric generators not being widely studied or adopted for practical applications.

[0005] Accordingly, there is a need for triboelectric generators formed of ubiquitous single materials. The use of a single material has the potential to simplify production of triboelectricgenerators, in addition to constituting a pathway for reducing the environmental burden of ubiquitous polymeric waste, by recycling them into high added value products capable of energy harvesting, and addressing the need to replace current state of the art fluoropolymer energy harvesters.

[0006] Any discussion of documents, acts, materials, devices, articles or the like which has been included in the present specification is not to be taken as an admission that any or all of these matters form part of the prior art base or were common general knowledge in the field relevant to the present disclosure as it existed before the priority date of each of the appended claims.SUMMARY

[0007] In a first aspect, disclosed herein is a laminate composition comprising a plurality of sequentially alternating layers of layer A and layer B, wherein:• layer A comprises a first set of fibres;• layer B comprises a second set of fibres; and• at least a portion of the first set of fibres have a cross-sectional diameter that is about or at least about 2, 3, 4, 5, 6, 7, 8, 9, or 10-times greater than at least a portion of the cross- sectional diameters of the second set of fibres, wherein:• at least a portion of the first set of fibres and the second set of fibres comprise the same material; and / or• at least a portion of the second set of fibres in layer B is interwoven with or extends into a portion of the fibres in one or more adjacent, overlaying or underlying layer A.

[0008] In a second aspect, disclosed herein is a triboelectric generator comprising a first generator element and a second generator element, the first and second generator elements being arranged so that relative movement between them generates a potential difference between them due to a triboelectrification effect, wherein:• the first generator element comprises a first laminate material, wherein the first laminate material is or comprises at least one laminate composition according to the first aspect; and• the second generator element comprises a second laminate material, wherein the second laminate materials is or comprises at least one laminate composition according to the first aspect, wherein the first laminate material and the second laminate material are arranged on the first generator element and the second generator element such that relative movement of the first and second generator elements can cause the first laminate material to come into contact with the second laminate material, and wherein the contact between one the first laminate material and the second laminate material generates electricity.

[0009] In a third aspect, disclosed herein is a method of generating electricity via the triboelectrification effect, the method comprising:• disposing a first laminate material as defined according to the first aspect on a first generator element; and• disposing a second laminate material as defined according to the first aspect on a second generator element, and applying one or more forces such that the first laminate material and second laminate material oscillate between contacting and separating.

[0010] In a fourth aspect, disclosed herein is a method of generating electricity with the triboelectric generator according to the second aspect, the method comprising:• exerting and releasing pressure along at least one axis one or more times, such that the first laminate material and second laminate material oscillate between contacting and separating;• exerting a tortional force one or more times such that the first laminate material and second laminate material oscillate between contacting and separating; or• a mixture thereof.

[0011] In a fifth aspect, disclosed herein is a substrate comprising at least one laminate material according to the first aspect, or a triboelectric generator according to the second aspect.

[0012] In a sixth aspect, disclosed herein is an article of clothing comprising at least one laminate material according to the first aspect, or a triboelectric generator according to the second aspect.

[0013] In a seventh aspect, disclosed herein is an article, optionally an article of clothing comprising at least one laminate material according to the first aspect, or a triboelectric generator according to the second aspect.

[0014] In an eighth aspect, disclosed herein is a method of manufacturing a laminate material, optionally a laminate material according to the first aspect, the method comprising:• deposition of a first set of fibres on at least one substrate;• deposition of a second set of fibres to form a first interface;• deposition of a further group of the first set of fibres on the second set of fibres to form a second interface, wherein at least a portion of the first set of fibres have a cross-sectional diameter that is about or at least about 2, 3, 4, 5, 6, 7, 8, 9, or 10-times greater than at least a portion of the cross- sectional diameters of the second set of fibres

[0015] In a ninth aspect, disclosed herein is a laminate material produced according to the eighth aspect.

[0016] In a tenth aspect, disclosed herein is a method of manufacturing a triboelectric generator, optionally a triboelectric generator according to the second aspect, the method comprising:• arranging a first generator element and a second generator element in an arrangement such that relative movement between the generator elements generates a potential difference between them due to a triboelectrification effect, wherein:• the first generator element comprises a first laminate material, wherein the first laminate material is or comprises at least one laminate composition according to the first aspect; and• the second generator element comprises a second laminate material, wherein the second laminate materials is or comprises at least one laminate composition according to the first aspect, wherein the first laminate material and the second laminate material are arranged on the first generator element and the second generator element such that relative movement of the first and second generator elements can cause the first laminate material to come in to contact with the second laminate material, and wherein the contact between one the first laminate material and the second laminate material generates electricity.

[0017] In an eleventh aspect, disclosed herein is a triboelectric generator produced according to the method of the tenth aspect.

[0018] In a twelfth aspect, disclosed herein is use of at least one laminate material according to any the first aspect, in the manufacture of a triboelectric generator.

[0019] In a thirteenth aspect, disclosed herein is use of at least one laminate material according to the first aspect, in the manufacture of a triboelectric generator according to the second aspect.

[0020] Other aspects and embodiments relating to the present disclosure are described herein. It will be appreciated that each example, aspect and embodiment of the present disclosure described herein is to be applied mutatis mutandis to each and every other example, aspect or embodiment unless specifically stated otherwise. The present disclosure is not to be limited in scope by the specific examples described herein, which are intended for the purpose of exemplification only. Functionally-equivalent substituents, compositions, methods and processes are clearly within the scope of the disclosure as described herein.BRIEF DESCRIPTION OF DRAWINGS

[0021] Whilst it will be appreciated that a variety of embodiments disclosed herein may be utilised, described herein are a number of examples with reference to the following drawings:

[0022] Figure 1 depicts: (a) raw foamed polystyrene (FPS) material; (b) dissolution of FPS in 0.15: 1 v v”1THF / DMF solution over 15 seconds; (c) distribution of fiber diameter from electrospun 10 to 30 wt% FPS solutions (N= 200); and (d) scanning electron microscopy (SEM) images for electrospun recycled polystyrene (rPS) small- and large-diameter fibres.

[0023] Figure 2 depicts: (a) an idealised schematic showing tightly bound versus loose / slip interfaces.

[0024] Figure 3 depicts: (a) helium ion microscopy (HIM) of a cryo-ion mill cut bilayer rPS laminate, showing the fiber ordering of the layers; and (b) cross-sectional scanning electron microscopy (SEM) image of a 15-bilayer rPS laminate.

[0025] Figure 4 depicts: (a) photograph of the peel testing configuration for testing the interlayer adhesion between fiber layers; and (b) force required to maintain a constant strain rate of 1.66 mm s-10when delaminating FPS 30 wt% solution-spun fibres (large diameter) onFPS 10 wt% solution-spun fibres (small diameter), and small-diameter fibres spun on large fibres.

[0026] Figure 5 depicts electromechanical voltage and current output from electrospun rPS laminates under 2-12 N cyclic compression; (a) three bilayers with alternating fixed-slip interfaces; (b) three bilayers with unordered fixed-slip interfaces; and (c) six layers assembled manually to remove any fixed interfaces.

[0027] Figure 6 depicts: (a) schematic (not to scale) demonstrating slip between large and small fibres during compression leading to individual charging events generating a triboelectric dipole, and subsequent macroscopic mechanical-to-electrical conversion; and (b) voltage generated from cyclic compression at between 2 and 12 N (A = IO N) of an aligned three- bilayer rPS stack; and (c) coherent anti-Stokes Raman scattering of rPS laminates; the images show the epi-CARS signal collected at increasing Z depths in a 30-bilayer structure, with the region appearing in the epi-CARS signal shown by the schematics below each surface.

[0028] Figure 7 depicts: (a) photographs of as produced 30-bilayer rPS laminates (25 x 25 mm); and (b) Schematic of piezoelectric mode testing with applied compressive force from 2 up to 12 N with no break in contact between the mechanical testing head and the sample.

[0029] Figure 8 depicts: (c) piezoelectric mode testing data of a 30-bilayer rPS laminate; i) Jscand ii) voltage measured across a 10 G resistor.

[0030] Figure 9 depicts energy harvesting from vibrations produced from air pressure changes; (a) schematic of sample setup with a syringe blowing 1 bar of air onto the sample, the needle is oscillated at 14-15 Hz between the edge of the sample and the centre with the current measured through the aluminium electrodes; (b) negligible current measured from air pressure changes on a dense polystyrene film; and (c) current measured from a 30-bilayer rPS laminate both initially and after 40000 cycles.

[0031] Figure 10 depicts vertical contact-separation triboelectric generator (TENG) testing of 30-bilayer rPS laminates at 0.1 m s-1; (a) photograph of the 30-bilayer laminate with polyester- sewn border; (b) schematic of the vertical contact-separation TENG mode testing configuration; and (c) characterisation of the peak-to-peak open-circuit voltage and the peak-to-peak short- circuit current for three configurations of the contact interface between the two individual 30-bilayer samples; large-diameter fibres contacting large-diameter fibres; small-diameter fibres contacting small-diameter fibres; and large-diameter fibres contacting small -diameter fibres.

[0032] Figure 11 depicts: (a) power and energy calculations for a 30-bilayer rPS TENG; and (b) charging a capacitor with 0.73 m s-1separation speed between two aligned 30-bilayer rPS laminates; left: charging the capacitor fully; right: time to reach 1 V charge in the capacitor.

[0033] Figure 12 depicts the fibre size for the small and large fibres respectively, which have average diameters of 80 nm and 800 nm. The second line shows the conversion of mechanical compression to current from (left) a 5-bilayer laminate; and (right) a 15-bilayer laminate. The third line shows the voltage output from the (left) 5-bilayer laminate; and (right) the 15-bilayer laminate. The final line shows the force curves used to obtain the data in the second and third line - with the key point being the use of 10N of force here.DETAILED DESCRIPTIONGeneral Terms

[0034] In the following description, reference is made to the accompanying drawings which form a part hereof, and which is shown, by way of illustration, several embodiments. It is understood that other embodiments may be utilised and structural changes may be made without departing from the scope of the present disclosure.

[0035] With regards to the definitions provided herein, unless stated otherwise, or implicit from context, the defined terms and phrases include the provided meanings. Unless explicitly stated otherwise, or apparent from context, the terms and phrases below do not exclude the meaning that the term or phrase has acquired by a person skilled in the relevant art. The definitions are provided to aid in describing particular embodiments, and are not intended to limit the claimed invention, because the scope of the invention is limited only by the claims. Furthermore, unless otherwise required by context, singular terms shall include pluralities and plural terms shall include the singular.

[0036] All publications discussed and / or referenced herein are incorporated herein in their entirety.

[0037] Throughout this disclosure, unless specifically stated otherwise or the context requires otherwise, reference to a single step, composition of matter, group of steps or group ofcompositions of matter shall be taken to encompass one and a plurality (i.e., one or more) of those steps, compositions of matter, groups of steps or groups of compositions of matter. Thus, as used herein, the singular forms “a”, “an” and “the” include plural aspects unless the context clearly dictates otherwise. For example, reference to “a” includes a single as well as two or more; reference to “an” includes a single as well as two or more; reference to “the” includes a single as well as two or more and so forth.

[0038] Those skilled in the art will appreciate that the disclosure herein is susceptible to variations and modifications other than those specifically described. It is to be understood that the disclosure includes all such variations and modifications. The disclosure also includes all of the examples, steps, features, methods, processes, and compositions, referred to or indicated in this specification, individually or collectively, and any and all combinations or any two or more of said steps or features.

[0039] The term “and / or”, e.g., “X and / or Y” shall be understood to mean either “X and Y” or “X or Y” and shall be taken to provide explicit support for both meanings or for either meaning.

[0040] Unless otherwise indicated, the terms “first,” “second,” etc. are used herein merely as labels, and are not intended to impose ordinal, positional, or hierarchical requirements on the items to which these terms refer. Moreover, reference to a “second” item does not require or preclude the existence of lower-numbered item (e.g., a “first” item) and / or a higher-numbered item (e.g., a “third” item).

[0041] As used herein, the phrase “at least one of’, when used with a list of items, means different combinations of one or more of the listed items may be used and only one of the items in the list may be needed. The item may be a particular object, thing, or category. In other words, “at least one of’ means any combination of items or number of items may be used from the list, but not all of the items in the list may be required. For example, “at least one of item A, item B, and item C” may mean item A; item A and item B; item B; item A, item B, and item C; or item B and item C. In some cases, “at least one of item A, item B, and item C” may mean, for example and without limitation, two of item A, one of item B, and ten of item C; four of item B and seven of item C; or some other suitable combination.

[0042] As used herein, the term “about”, unless stated to the contrary, typically refers to a range of up to + / - 10% of the designated value, and includes smaller ranges therein, for example + / - 5% or + / - 1% of the designated value.

[0043] It is to be appreciated that certain features that are, for clarity, described herein in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features that are, for brevity, described in the context of a single embodiment, may also be provided separately or in any sub-combination.

[0044] Throughout the present specification, various aspects and components of the invention can be presented in a range format. The range format is included for convenience and should not be interpreted as an inflexible limitation on the scope of the invention. Accordingly, the description of a range should be considered to have specifically disclosed all the possible subranges as well as individual numerical values within that range, unless specifically indicated. For example, description of a range such as from 1 to 5 should be considered to have specifically disclosed sub-ranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 5, from 3 to 5 etc., as well as individual and partial numbers within the recited range, for example, 1, 2, 3, 4, 4.5, 4.75, and 5, unless where integers are required or implicit from context. This applies regardless of the breadth of the disclosed range. Where specific values are required, these will be indicated in the specification.

[0045] Throughout this specification the word "comprise", or variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated element, integer or step, or group of elements, integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps.

[0046] Throughout this specification, the term "consisting essentially of' is intended to exclude elements which would materially affect the properties of the claimed composition, method or process.

[0047] The terms "comprising", "comprise" and "comprises" herein are intended to be optionally substitutable with the terms "consisting essentially of, "consist essentially of, "consists essentially of, "consisting of, "consist of and "consists of, respectively, in every instance.

[0048] Herein “weight %” may be abbreviated to as “wt%” or “wt.%”. The weight % may be w / w or w / v, unless specifically indicated or clear from context.Specific Terms

[0049] Herein “a portion of the first set of fibres” may be about, less than about, or at least about (wt.%): 1, 2, 3, 4, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 97, 98, 99, 99.9.

[0050] Herein “a portion of the second set of fibres” may be about, less than about, or at least about (wt.%): 1, 2, 3, 4, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 97, 98, 99, 99.9.

[0051] In one or more embodiments “the same material” refers to two or more materials having the same or substantially the same chemical compositions, e.g., alloys and ceramics of substantially the same composition, or polymers formed of the same monomers, but not necessarily requiring the same chain length and / or branching structure.

[0052] In one or more embodiments, the terms “laminate”, “laminate composition” or “laminate material”, as used herein, refers to a material comprising two or more films and / or layers stacked together to form a composite material. The “laminate”, “laminate composition” or “laminate material”, as used herein, may comprise one or more fixed interface and / or one or more slip interface. In one or more embodiments the one or more fixed interface and one or more slip interface may alternate.Compositions

[0053] Disclosed herein is a laminate composition comprising a plurality of sequentially alternating layers of layer A and layer B, wherein:• layer A comprises a first set of fibres;• layer B comprises a second set of fibres; and• at least a portion of the first set of fibres have a cross-sectional diameter that is about or at least about 2, 3, 4, 5, 6, 7, 8, 9, or 10-times greater than at least a portion of the cross- sectional diameters of the second set of fibres, wherein:• at least a portion of the first set of fibres and the second set of fibres comprise the same material; and / or• at least a portion of the second set of fibres in layer B is interwoven with or extends into a portion of the fibres in one or more adjacent, overlaying or underlying layer A.

[0054] Herein a laminate material, for example a first laminate material and / or a second laminate material, may comprise one or more laminate compositions as defined herein.

[0055] In one embodiment, at least a portion of the second set of fibres in layer B is interwoven with or extends into a portion of the fibres in an adjacent underlying layer A.

[0056] It will be understood by the person skilled in the art that the fibres at the interfaces between each layer A and layer B, may be interwoven with or extend into one another. Without intending to be limited by theory, it is believed that the extent of interweaving or extending of fibres between two layers will in part determine the extent of adhesive force between the layers. The person skilled in the art will accordingly understand, that greater interweaving or extending of fibres may provide a greater adhesive force between the layers. It will be understood that the laminate compositions of the present disclosure may exhibit different interfacial adhesive forces between each layer A and layer B, such that the laminate composition may be conceived of as possessing a plurality of ‘fixed’ interfaces, and a plurality of ‘slip’ interfaces (or non-fixed interface), wherein the fixed interfaces have a higher interfacial adhesive force than that of the slip interfaces.

[0057] The adhesive force of the fixed interfaces and the slip interfaces may be defined in absolute terms or in relative terms. In some embodiments, the adhesion force of the fixed interface (in mN) may be about, at least about, or less than about: 0.005 0.01, 0.015, 0.020.025, 0.03, 0.035, 0.04, 0.045, 0.05, 0.055. 0.06, 0.065, 0.07, 0.075, 0.08, 0.085, 0.09, 0.095, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7 0.8 0.9, or 1. In some embodiments, the adhesion force of the slip interface (in mN) may be about, at least about, or less than about: 0.001, 0.002, 0.003, 0.004, 0.005, 0.006, 0.007, 0.008, 0.009, 0.01, 0.011, 0.012, 0.013, 0.014, 0.015, 0.016, 0.017, 0.018, 0.019, 0.02, 0.025, 0.03, 0.035, 0.04, 0.045, 0.05, 0.055, 0.06, 0.065, 0.07, 0.075, 0.08, 0.085, 0.09, 0.1, 0.2, 0.03, 0.04, or 0.05. In some embodiments, the ratio of the adhesion force of the fixed interface may be about, at least about, or less than about, 1.2, 1.4, 1.6, 1.8, 2, 2.2, 2.4, 2.6, 2.8, 3.0, 3.2, 3.4, 3.6, 3.8, 4.0, 4.5, 5, 5.5, 6, 6.5, 7, 7.5, 8, 8.5, 9, 9.5, or 10 times the adhesion force of the slip interface. In one or more embodiments, the adhesion force is in a range of any two of the exemplified values recited herein. The adhesive force may be measured by an appropriate method known in the art, for example ASTM D4541-22 as updated 29 July 2022.

[0058] In one embodiment, at least a portion of the first set of fibres in layer A, is interwoven with or extends into, a portion of the fibres in one or more adjacent, overlaying or underlying layer B, to an extent less than that which the at least a portion of the second set of fibres in layer B is interwoven with or extends into a portion of the fibres in one or more adjacent, overlaying or underlying layer A. In a particular embodiment, at least a portion of the first set of fibres in layer A, is interwoven with or extends into, a portion of the fibres in one or more adjacent, overlaying or underlying layer B, to an extent less than that which the at least a portion of the second set of fibres in layer B is interwoven with or extends into a portion of the fibres in an adjacent underlying layer A.

[0059] In a particular embodiment, there is substantially no interweaving or extension of the first set of fibres in layer A, with the fibres in one or more adjacent, overlaying or underlying layer B. In a particular embodiment, there is substantially no interweaving or extension of the first set of fibres in layer A, with the fibres in an adjacent underlying layer B.

[0060] In one embodiment, the percentage of layer B, relative to all layer B within the plurality of sequentially alternating layers, for which least a portion of the second set of fibres therein is interwoven with or extends into a portion of the fibres in one or more adjacent, overlaying or underlying layer A is about or greater than about 75%. In one embodiment, the percentage of layer B, relative to all layer B within the plurality of sequentially alternating layers, for which least a portion of the second set of fibres therein is interwoven with or extends into a portion of the fibres in an adjacent underlying layer A is about or greater than about 75%.

[0061] In one embodiment, the percentage of layer A, relative to all layer A within the plurality of sequentially alternating layers, for which at least a portion of the first set of fibres therein is interwoven with or extends into, a portion of the fibres in one or more adjacent, overlaying or underlying layer B, to an extent less than the extent to which the at least a portion of the second set of fibres in layer B is interwoven with or extends into a portion of the fibres in one or more adjacent, overlaying or underlying layer A, is about or greater than about 75%. In one embodiment, the percentage of layer A, relative to all layer A within the plurality of sequentially alternating layers, for which at least a portion of the first set of fibres therein is interwoven with or extends into, a portion of the fibres in an adjacent underlying layer B, to an extent less than the extent to which the at least a portion of the second set of fibres in layer B is interwoven with or extends into a portion of the fibres in an adjacent underlying layer A, is about or greater than about 75%.

[0062] In one embodiment, the percentage of layer B, relative to all layer B within the plurality of sequentially alternating layers, for which least a portion of the second set of fibres therein is interwoven with or extends into a portion of the fibres in one or more adjacent, overlaying or underlying layer A is about or greater than about 75%; and / or the percentage of layer A, relative to all layer A within the plurality of sequentially alternating layers, for which at least a portion of the first set of fibres therein is interwoven with or extends into, a portion of the fibres in one or more adjacent, overlaying or underlying layer B, to an extent less than the extent to which the at least a portion of the second set of fibres in layer B is interwoven with or extends into a portion of the fibres in one or more adjacent, overlaying or underlying layer A, is about or greater than about 75%. In one embodiment, the percentage of layer B, relative to all layer B within the plurality of sequentially alternating layers, for which least a portion of the second set of fibres therein is interwoven with or extends into a portion of the fibres in an adjacent underlying layer A is about or greater than about 75%; and / or the percentage of layer A, relative to all layer A within the plurality of sequentially alternating layers, for which at least a portion of the first set of fibres therein is interwoven with or extends into, a portion of the fibres in an adjacent underlying layer B, to an extent less than the extent to which the at least a portion of the second set of fibres in layer B is interwoven with or extends into a portion of the fibres in an adjacent underlying layer A, is about or greater than about 75%.

[0063] In one embodiment, the first set of fibres have a cross-sectional diameter of about, or at least about: 2, 3, 4, 5, 6, 7, 8, 9, or 10-times at least a portion of the cross-sectional diameters of the second set of fibres. In one embodiment the first set of fibres have a cross-sectional diameter of about, or at least about 2 times at least a portion of the cross-sectional diameters of the second set of fibres. In one embodiment the first set of fibres have a cross-sectional diameter of about, or at least about 3 times at least a portion of the cross-sectional diameters of the second set of fibres. In one embodiment the first set of fibres have a cross-sectional diameter of about, or at least about 4 times at least a portion of the cross-sectional diameters of the second set of fibres. In one embodiment the first set of fibres have a cross-sectional diameter of about, or at least about 5 times at least a portion of the cross-sectional diameters of the second set of fibres. In one embodiment the first set of fibres have a cross-sectional diameter of about, or at least about 6 times at least a portion of the cross-sectional diameters of the second set of fibres. In one embodiment the first set of fibres have a cross-sectional diameter of about, or at least about7 times at least a portion of the cross-sectional diameters of the second set of fibres. In one embodiment the first set of fibres have a cross-sectional diameter of about, or at least about 8 times at least a portion of the cross-sectional diameters of the second set of fibres. In one embodiment the first set of fibres have a cross-sectional diameter of about, or at least about 9 times at least a portion of the cross-sectional diameters of the second set of fibres. In one embodiment the first set of fibres have a cross-sectional diameter of about, or at least about 10 times at least a portion of the cross-sectional diameters of the second set of fibres.

[0064] In one embodiment, at least a portion of the first set of fibres has a cross-sectional diameter, or mean, mode or median cross-sectional diameter, in a range of about 0.50 pm to about 50.00 pm, optionally in a range of about 10 pm to about 20 pm. For example, the cross- sectional diameter, or mean, mode or median cross-sectional diameter, for at least a portion of the first set of fibres may be about, at least about, or less than about (in pm): 0.50, 1.00, 2.00, 3.00, 4.00, 5.00, 6.00, 7.00, 8.00, 9.00, 10.00, 12.00, 14.00, 16.00, 18.00, 20.00, 22.00, 24.00, 26.00, 28.00, 30.00, 35.00, 40.00, 45.00, or 50.00. In one or more embodiments, the cross- sectional diameter, or mean, mode or median cross-sectional diameter, for at least a portion of the first set of fibres, is in a range of any two of the exemplified values recited herein.

[0065] In one embodiment, at least a portion of the second set of fibres has a cross-section diameter in a range of about 0.05 pm to about 5.00 pm, optionally between about 1 to about 2 pm. For example, the cross-sectional diameter, or mean, mode or median cross-sectional diameter, for at least a portion of the second set of fibres, may be about, at least about, or less than about (in pm): 0.05, 0.10, 0.25, 0.50, 0.75, 1.00, 1.25, 1.50, 1.75, 2.00, 2.25, 2.50, 2.75, 3.00, 3.25, 3.50, 3.75, 4.00, 4.25, 4.50, 4.75, or 5.00. In one or more embodiments, the cross- sectional diameter, or mean, mode or median cross-sectional diameter, for at least a portion of the second set of fibres, is in a range of any two of the exemplified values recited herein

[0066] In one embodiment, the first set of fibres has a cross-sectional diameter in a range of about 0.50 pm to about 50.00 pm, optionally in a range of about 10 pm to about 20 pm; and / or the second set of fibres has a cross-section diameter in a range of about 0.05 pm to about 5.00 pm, optionally between about 1 to about 2 pm.

[0067] In one embodiment the “roughness” of at least a portion of the first set of fibres is greater than a portion of the second set of fibres. Any surface irregularities, coarseness or roughness on the first and / or second set of fibres may be generated intentionally or may becreated by numerous factors such as, but not limited to the specific method used in their creation and / or the physical properties of one or more materials used in the formation of a set of fibres.

[0068] Quantification of surface coarseness or roughness may be associated with measuring height, depth, and intervals along a portion of fibre. This data may be analysed by a standard method and calculated as per industrial quantities standards. For example, atomic force microscopy (AFM) of individual fibres, and / or optical profilometry of a laminate surface. The roughness of one or more fibres may be analysed using any method known in the art. The technique used may be a contact or non-contact type method.

[0069] In one embodiment, the radius of curvature of at least a portion of the fibres in the second set of fibres is about, or at least about (%): 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20, of the radius of curvature of at least a portion of fibres in the first set of fibres. For example, the radius of curvature of at least a portion of the fibres in the second set of fibres is about, or at least about 10%, of the radius of curvature of at least a portion of fibres in the first set of fibres.

[0070] In one embodiment, at least a portion of the first set of fibres have a larger variation in aspect ratio along a length of the first set of fibres in comparison to at least a portion of the second set of fibres.

[0071] In one embodiment, a portion of the first set of fibres in at least one layer A is interwoven with a portion of the second set of fibres in the adjacent, overlaying or underlying layer B. In another embodiment, a portion of the first set of fibres in a plurality of layer A is interwoven with a portion of the second set of fibres in the relevant adjacent, overlaying or underlying layers B.

[0072] In one embodiment, a portion of the second set of fibres in at least one layer B is interwoven with a portion of the first set of fibres in the adjacent, overlaying or underlying layer A. In another embodiment, a portion of the second set of fibres in a plurality of layer B is interwoven with a portion of the first set of fibres in the relevant adjacent, overlaying or underlying layers A.

[0073] In one embodiment, a portion of one or more fibres in the first set of fibres in at least one layer A extends into an adjacent, overlaying or underlying layer B. For example, a portion of the fibre may protrude with or without entwinning or interweaving. In another embodiment,a portion of the first set of fibres in a plurality of layer A is extends into a relevant adjacent, overlaying or underlying layers B.

[0074] In one embodiment, a portion of the second set of fibres in at least one layer B is not interwoven with a portion of the first set of fibres in one or more adjacent, underlying, layer A. In another embodiment, a portion of the second set of fibres in a plurality of layer B is not interwoven with a portion of the first set of fibres in the relevant adjacent, overlaying or underlying layers A.

[0075] In one embodiment, a portion of the first set of fibres in at least one layer A is not interwoven with a portion of the second set of fibres in one or more adjacent, underlying, layer B. In another embodiment, a portion of the first set of fibres in a plurality of layer A is not interwoven with a portion of the second set of fibres in the relevant adjacent, overlaying or underlying layers B.

[0076] In one embodiment, in one or more layer A, at least a portion of the first set of fibres comprise fibres with a cross-sectional diameter in a range of about 0.50 pm to about 50.00 pm, optionally in a range of about 10 pm to about 20 pm. In another embodiment, in one or more layer A, the mean, median or mode cross-sectional diameter of at least a portion of the first set of fibres comprise fibres in a range of about 0.50 pm to about 50.00 pm, optionally in a range of about 10 pm to about 20 pm. In yet another embodiment, in one or more layer A, about, or at least about (wt.%): 1, 2, 3, 4, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 97, 98, 99, or 99.9, of a portion of the first set of fibres, comprise fibres with a cross- sectional diameter in a range of: about 0.50 pm to about 50.00 pm, about 1.00 pm to about 40.00 pm, about 1.00 pm to about 30.00 pm, about 5.00 pm to about 20.00 pm, or about 10.00 pm to about 20.00 pm. For example, the cross-sectional diameter, or mean, mode or median cross-sectional diameter, may be about, at least about, or less than about (in pm): 0.50, 1.00, 2.00, 3.00, 4.00, 5.00, 6.00, 7.00, 8.00, 9.00, 10.00, 12.00, 14.00, 16.00, 18.00, 20.00, 22.00, 24.00, 26.00, 28.00, 30.00, 35.00, 40.00, 45.00, or 50.00. In one or more embodiments, the cross-sectional diameter, or mean, mode or median cross-sectional diameter is in a range of any two of the exemplified values recited herein.

[0077] In one embodiment, in one or more layer B, at least a portion of the second set of fibres comprise fibres with a cross-sectional diameter in a range of about 0.05 pm to about 5.00 pm, optionally between about 1.00 to about 2.00 pm. In another embodiment, in one or more layerB, the mean, median or mode cross-sectional diameter of at least a portion of the second set of fibres comprise fibres in a range of about 0.05 pm to about 5.00 pm, optionally between about 1.00 to about 2.00 pm. In yet another embodiment, in one or more layer B, about, or at least about (wt.%): 1, 2, 3, 4, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 97, 98, 99, or 99.9, of a portion of the second set of fibres, comprise fibres with a cross-sectional diameter in a range of: about 0.05 pm to about 5.00 pm, about 0.50 pm to about 4.50 pm, about 0.5 pm to about 4.00 pm, about 0.50 pm to about 3.50 pm, about 0.50 pm to about 3.00 pm, about 0.5 pm to about 2.00 pm, or about 1.00 to about 2.00 pm. For example, the cross- sectional diameter, or mean, mode or median cross-sectional diameter, may be about, at least about, or less than about (in pm): 0.05, 0.10, 0.25, 0.50, 0.75, 1.00, 1.25, 1.50, 1.75, 2.00, 2.25, 2.50, 2.75, 3.00, 3.25, 3.50, 3.75, 4.00, 4.25, 4.50, 4.75, or 5.00. In one or more embodiments, the cross-sectional diameter, or mean, mode or median cross-sectional diameter is in a range of any two of the exemplified values recited herein.

[0078] In one embodiment at least one layer A has a thickness, a mean thickness or a median thickness of about, at least about, or less than about (in pm): 500, 450, 400, 350, 300, 200, 250, 200, 150, 100, or 50. In one embodiment a plurality of layer A’s have a thickness, a mean thickness or a median thickness of about, at least about, or less than about (in pm): 500, 450, 400, 350, 300, 200, 250, 200, 150, 100, or 50. The thickness of at least one layer may be in a range of any two of the values recited herein.

[0079] In one embodiment at least one layer B has a thickness, a mean thickness or a median thickness of about, at least about, or less than about (in pm): 5.00, 4.50, 4.00, 3.50, 3.00, 2.00, 2.50, 2.00, 1.50, or 1.00. In one embodiment a plurality of layer B’s have a thickness, a mean thickness or a median thickness of about, at least about, or less than about (in pm): 5.00, 4.50, 4.00, 3.50, 3.00, 2.00, 2.50, 2.00, 1.50, or 1.00. The thickness of at least one layer may be in a range of any two of the values recited herein.

[0080] In one embodiment, about, or at least about (wt.%): 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 97, 98, 99, or 99.9, of one or more layer A comprises the first set of fibres. In another embodiment, about, or at least about (wt.%): 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 97, 98, 99, or 99.9, of a plurality of layer A’s (for example: 2, 3, 4, 5, 6, 7, 8, 9 or 10), comprise the first set of fibres For example, in one embodiment, at least about 75 wt% of one or more layer A comprises the first set of fibres.

[0081] In one embodiment, about, or at least about (wt.%): 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 97, 98, 99, or 99.9, of one or more layer B comprises the second set of fibres. In another embodiment, about, or at least about (wt.%): 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 97, 98, 99, or 99.9, of a plurality of layer B’s (for example: 2, 3, 4, 5, 6, 7, 8, 9 or 10), comprise the second set of fibres For example, in one embodiment, at least about 75 wt% of one or more layer B comprises the second set of fibres.

[0082] In one embodiment, one or more layer A consists essentially of the first set of fibres. In another embodiment, a plurality of layer A’s (for example: 2, 3, 4, 5, 6, 7, 8, 9 or 10), consist essentially of the first set of fibres.

[0083] In one embodiment, one or more layer B consists essentially of the second set of fibres. In another embodiment, a plurality of layer B’s (for example: 2, 3, 4, 5, 6, 7, 8, 9 or 10), consist essentially of the second set of fibres.

[0084] In one embodiment a laminate as described herein comprises at least one other layer of material in addition to one or more layer A and one or more layer B. In one embodiment, the at least one other lay of material comprises or consists of at least one of: an optional covering layer; an electrode for harvesting charge (for example a metal foil such as Al or Cu), optionally disposed above and / or below a top and / or bottom surface; an encapsulation layer, for example based on or obtained from a polymer such as Kapton or polydimethylsiloxane to prevent damage to the laminate structure. In one embodiment the laminate comprises a coating. In one embodiment the coating does not or substantially does not fill voids present in the laminate structure.

[0085] In one embodiment the first set of fibres, as described herein, and / or the second set of fibres, as described herein, comprise or consist essentially of a material selected from, but not limited to: a dielectric material, a ferroelectric material, an elastomer, a thermoplastic, and mixtures thereof.

[0086] Dielectric materials, including polymeric dielectric materials, are known to persons skilled in the art. There is no particular limitation as to suitable dielectric materials. Examples of suitable polymeric dielectric materials include, but are not limited to, one or more of: polyacrylates, polyimides, polyvinyl alcohol, polystyrene, polyester, polycarbonate, polyhaloethylene, epoxy resins, siloxane polymers, benzocyclobutene-based polymers, and mixtures thereof. Other polymeric dielectrics are described in U.S. Patent Nos. 7,605,394;7,981,989; 8,093,588; 8,274,075; 8,338,555; U.S. Patent Publication Nos. 2011 / 0175089; 2011 / 0215334; 2012 / 0068314, the contents of each of which is hereby incorporated by reference in its entirety. Further suitable examples of polymeric dielectric materials include, but are not limited to one or more of: polyethylene (PE), polypropylene (PP), polytetrafluoroethylene (PTFE, Teflon), polyvinylidene fluoride (PVDF), polystyrene (PS), polyethylene terephthalate (PET), polyimide (PI), polycarbonate (PC), polyvinyl chloride (PVC), polymethyl methacrylate (PMMA), polyether ether ketone (PEEK), polyamide (Nylon), polyvinyl alcohol (PVA), polysulfone (PSU), polyetherimide (PEI), polyoxymethylene (POM, Delrin), polyaryletherketone (PAEK), polybenzimidazole (PBI), polychlorotrifluoroethylene (PCTFE), polyether sulfone (PES), polyethylene naphthalate (PEN), polydimethylsiloxane (PDMS), polyphenylene sulfide (PPS), polytetrafluoroethylene-perfluoroalkoxy (PFA), poly vinylidene chloride (PVDC), polysiloxane, polyurethane (PU), polybenzoxazole (PBO), polyparaphenylene (PPP), polytetrafluoroethylene-ethylene (ETFE), and mixtures thereof.

[0087] Ferroelectric materials, including ferroelectric polymers, are known to persons skilled in the art. There is no particular limitation as to suitable ferroelectric materials. Examples of suitable of ferroelectric polymers include, but are not limited to, one or more of: poly vinylidene fluoride (PVDF)-based polymers, polyundecanoamide (Nylon l l)-based polymers, or blends of PVDF -based polymers or polyundecanoamide (Nylon 1 l)-based polymers, or mixtures thereof. The PVDF -based polymer can be a homopolymer, a copolymer, or a terpolymer, or a blend thereof. A non-limiting example of a PVDF-based homopolymer polymer is PVDF. Nonlimiting examples of PVDF-based copolymers are poly(vinylidene fluoride-tetrafluoro ethylene) (P(VDF-TrFE)), poly(vinylidene-fluoride-co-hexafluoropropene) (P(VDF-HFP)), poly(vinylidene-fluoride-chlorotrifluoroethylene) (P(VDF-CTFE)) or poly(vinylidene- fluori de-chl orofluoroethy 1 ene) (P( VDF-CFE)) .

[0088] Elastomers are known to persons skilled in the art. There is no particular limitation as to suitable elastomers. Examples of suitable elastomers include, but are not limited to, one or more of: styrene-butadiene rubber (SBR), butadiene rubber (BR), isoprene rubber (IR), nitrilebutadiene rubber (NBR), nitrile-isoprene rubber (NIR), diene rubber such as chloroprene rubber (CR);Butyl rubber (UR), ethyl ene-propyl ene rubber (EPM, EPDM), chlorosulfonated polyethylene (olefinic rubbers such as C5M), ether rubbers such as epichlorohydrin rubbers (silicone rubbers, fluoro-rubbers, acrylic rubbers, urethane rubbers, as well as styrene-based, olefin-based, polyvinyl chloride-based, and urethane-based rubbers), polyester, polyamide,elastomer materials such as thermoplastic elastomers such as fluorine-based and chlorinated polyethylene-based elastomers, and mixtures thereof.

[0089] Thermoplastics are known to person skilled in the art. There is no particular limitation as to suitable thermoplastics. Examples of suitable thermoplastics include, but are not limited to, one or more of: amorphous thermoplastics, semi-crystalline thermoplastics, crystalline thermoplastics, and elastomeric thermoplastics, and include, without limitation, poly(aryletherketone) (PAEK), poly(butylene terephthalate) (PBT), poly(butyrate), poly(ether ether ketone) (PEEK), poly(etherimide) (PEI), poly(2 -hydroxyethyl methacrylate) (pHEMA), poly(isocyanurate) (PIR), poly(methyl methacrylate) (PMMA), poly(oxymethylene) (POM); poly (phenyl sulfone) (PPSF), poly(styrene) (PS), poly(trimethylene terephthalate) (PTT), poly(urea) (PU); poly(amide)-based thermoplastics like aliphatic poly(amides), poly(phthalamides) (PPA), and aramides (aromatic poly(am ides)); poly(carbonate)- based thermoplastics; poly(ester)-based thermoplastics like poly(ethylene)naphthalate (PEN), and polyethylene terephthalate) (PET); poly(olefin)-based thermoplastics like poly(ethylene) (PE), poly(propylene) (PP), polypropylene carbonate) (PPC), poly(methylpentene) (PMP), and poly(butene-l) (PB-1); poly(stannane)-based thermoplastics; poly(sulfone)- based thermoplastics; poly(vinyl)-based thermoplastics like poly(vinyl chloride) (PVC), poly(vinylidene fluoride) (PVDF), poly(vinyl fluoride) (PVF), poly(vinyl nitrate) (PVN), and poly-(4-vinylphenol) (PVP); and cellulose-based thermoplastic like cellulose ester-based thermoplastics and cellulose ether-based thermoplastics, and mixtures thereof.

[0090] In one embodiment the first set of fibres, as described herein, and / or the second set of fibres, as described herein, comprise or consist essentially of a dielectric material. In one embodiment the first set of fibres, as described herein, and / or the second set of fibres, as described herein, comprise or consist essentially of ferroelectric material. In one embodiment the first set of fibres, as described herein, and / or the second set of fibres, as described herein, comprise or consist essentially of an elastomer. In one embodiment the first set of fibres, as described herein, and / or the second set of fibres, as described herein, comprise or consist essentially of a thermoplastic. In one embodiment the first set of fibres, as described herein, and / or the second set of fibres, as described herein, comprise or consist essentially of a mixture of different materials thereof.

[0091] In one embodiment the first set of fibres, as described herein, and / or the second set of fibres, as described herein, may comprise or consist essentially of: polystyrene, silk,polycaprolactone, polylactic acid, ethyl vinyl acetate, polyvinylidene difluoride (and associated co-polymers), and mixtures thereof.

[0092] In one embodiment at least a portion of the first fibres and at least a portion of the second fibres comprise or consist essentially of the same material. In one embodiment at least a portion of the first fibre and at least a portion of the second fibres comprise the same material.

[0093] In one embodiment the first set of fibres and / or the second set of fibres comprise or consist essentially of polystyrene. In one embodiment the first set of fibres comprise or consist essentially of polystyrene. In one embodiment the second set of fibres comprise or consist essentially of polystyrene.

[0094] In another embodiment the first set of fibres and / or the second set of fibres comprise or consist essentially of foamed polystyrene. In another embodiment the first set of fibres comprise or consist essentially of foamed polystyrene. In another embodiment the second set of fibres comprise or consist essentially of foamed polystyrene.

[0095] In one embodiment the first set of fibres and / or the second set of fibres comprise or consist essentially of polyvinylidene difluoride (and associated co-polymers). In one embodiment the first set of fibres comprise or consist essentially of polyvinylidene difluoride (and associated co-polymers). In one embodiment the second set of fibres comprise or consist essentially of polyvinylidene difluoride (and associated co-polymers).

[0096] In another embodiment the first set of fibres and / or the second set of fibres comprise or consist essentially of a recycled material. In another embodiment the first set of fibres comprise or consist essentially of a recycled material. In another embodiment the second set of fibres comprise or consist essentially of a recycled material.

[0097] In one embodiment:• one or more layer A’s; and / or• one or more layer B’s further comprise as least one excipient. The one or more excipients may modify the chemical, electrical and / or mechanical properties of one or more materials used in the laminate, and may influence charging characteristics. The influence of one or more excipients may depend on factors such as particle size and / or concentration. One or more surfaces of the laminate or triboelectric generator may also modified by the addition of one or more functional groups thatwould influence attributes such as adhesion, which in turn influence the charging. In one embodiment, additives, for example nanomaterial additives, can be added to an ink / composition prior to laminate fabrication either for (not both in the same laminate) Layer A or Layer B to enhance electrification phenomenon.

[0098] In one embodiment, at least one layer A and / or at least one layer B, is modified to introduce at least one functional group. The term “functional group” or “substituent” as used herein refers to a group that can be or is substituted onto a molecule or onto an organic group. Examples of substituents or functional groups include, but are not limited to, one or more of: a halogen (e.g., F, Cl, Br, and I); an oxygen atom in groups such as hydroxyl groups, alkoxy groups, aryloxy groups, aralkyloxy groups, oxo(carbonyl) groups, carboxyl groups including carboxylic acids, carboxylates, and carboxylate esters; a sulfur atom in groups such as thiol groups, alkyl and aryl sulfide groups, sulfoxide groups, sulfone groups, sulfonyl groups, and sulfonamide groups; a nitrogen atom in groups such as amines, hydroxylamines, nitriles, nitro groups, N-oxides, hydrazides, azides, and enamines; and other heteroatoms in various other groups. Non-limiting examples of substituents that can be bonded to a substituted carbon (or other) atom include F, Cl, Br, I, OR, OC(O)N(R')2, CN, NO, NO2, ONO2, azido, CF3, OCF3, R, O (oxo), S (thiono), C(O), S(O), methylenedioxy, ethylenedioxy, N(R)2, SR, SOR, SO2R', SO2N(R)2, SO3R, C(O)R, C(O)C(O)R, C(O)CH2C(O)R, C(S)R, C(O)OR, OC(O)R, C(O)N(R)2, OC(O)N(R)2, C(S)N(R)2, (CH2)O-2N(R)C(0)R, (CH2)O-2N(R)N(R)2,N(R)N(R)C(O)R, N(R)N(R)C(O)OR, N(R)N(R)CON(R)2, N(R)SO2R, N(R)SO2N(R)2, N(R)C(O)OR, N(R)C(O)R, N(R)C(S)R, N(R)C(O)N(R)2, N(R)C(S)N(R)2, N(COR)COR, N(0R)R, C(=NH)N(R)2, C(O)N(OR)R, or C(=NOR)R wherein R can be hydrogen or a carbonbased moiety, and wherein the carbon-based moiety can itself be further substituted; for example, wherein R can be hydrogen, alkyl, acyl, cycloalkyl, aryl, aralkyl, heterocyclyl, heteroaryl, or heteroarylalkyl, wherein any alkyl, acyl, cycloalkyl, aryl, aralkyl, heterocyclyl, heteroaryl, or heteroarylalkyl; or wherein two R groups bonded to a nitrogen atom or to adj acent nitrogen atoms can together with the nitrogen atom or atoms form a heterocyclyl, which can be mono- or independently multi -substituted with one or more “functional groups”, as described herein.

[0099] In another embodiment a laminate described herein may comprise or comprise at least: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, or 40 layers of layer A as described herein. In another embodiment a laminate described herein may comprise or comprise at least: 1, 2, 3, 4, 5, 6, 7,8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, or 40 layers of layer B as described herein. In another embodiment a laminate described herein may comprise or comprise in total at least: 2, 3, 4, 5, 6, 7, 8, 9, 10,11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35,36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60,61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, or 80 layers of layer A and layer B, as described herein. In one embodiment, a laminate material, as described herein, comprises a total of or at least 10 layers of layer A and layer B, each as described herein. In another embodiment, a laminate material, as described herein, comprises a total of or at least 20 layers of layer A and layer B, each as described herein. In another embodiment, a laminate material, as described herein, comprises a total of or at least 30 layers of layer A and layer B, each as described herein. In another embodiment, a laminate material, as described herein, comprises a total of or at least 40 layers of layer A and layer B, each as described herein. In another embodiment, a laminate material, as described herein, comprises a total of or at least 50 layers of layer A and layer B, each as described herein. In another embodiment, a laminate material, as described herein, comprises a total of or at least 60 layers of layer A and layer B, each as described herein.Processes / Methods of Manufacture

[0100] Herein, at least a portion of the first set of fibres and / or the second set of fibres, as described herein, may be produced by an appropriate technique known in the art. For example, the one or more techniques may be selected from, but not limited to: electrospinning, interfacial polymerisation, freeze-drying synthesis, template synthesis, self-assembly, phase separation, spinneret-based tunable engineered parameter, drawing, printing, lay-by-layer deposition, dip coating, pin coating, melt blowing, or a combination thereof.

[0101] In one embodiment, at least a portion of the first set of fibres and / or the second set of fibres is produced by electrospinning. In another embodiment, at least a portion of the first set of fibres is produced by electrospinning. In another embodiment, at least a portion of the second set of fibres is produced by electrospinning.

[0102] The present disclosure also provides for a method of manufacturing a laminate material according as described herein, the method comprising:• deposition of a first set of fibres as described herein, on at least one substrate;• deposition of a second set of fibres as described herein, on top of the first set of fibres, to form an interface;• deposition of a further group of the first set of fibres on the second set of fibres to form an interface.

[0103] In one embodiment, the first interface is a fixed interface, and the second interface is a non-fixed interface.

[0104] In one embodiment, the deposition of the second set of fibres on top of the first set of fibres, comprises the use of electric fields on pressure.

[0105] In one embodiment, the method further comprises sequential repetition of the steps of: deposition of a second set of fibres as described herein, on top of the first set of fibres, to form an interface; and deposition of the first set of fibres on the second set of fibres to form an interface.

[0106] It will be understood that by sequentially depositing the second and first set of fibres on top of one another to form alternating fixed and non-fixed interfaces, a laminate material of having a predetermined number of layers as described above may be manufactured.

[0107] The person skilled in the art will appreciate that one of a number of possible methods (or combinations thereof) may be used in order to perform the initial and any subsequent deposition of the sets of fibres. There is no particular limitation as to suitable methods.

[0108] In one embodiment, the method comprises electrospinning. In electrospinning, the polymer dissolved in a relevant solvent is subjected to an electric field between an extrusion needle and a metallic foil. The fibre diameter is controlled via the concentration of polymer in the relevant solvent used for electrospinning (higher concentration = larger fibre diameter).

[0109] In another embodiment, the method comprises vacuum filtration, whereby individual fibres of desired diameter are produced and suspended in a solvent, followed by vacuum deposition onto a porous metallic substrate. In such case, the fibre diameter is defined through pre-production processes and pressure is used to create the fixed interfaces.

[0110] In another embodiment, the method comprises spray coating, whereby alternating layers of fibres are sprayed onto large area substrates vertically. In such case, a vertical approachis critical to ensure penetration of the small fibres into the large fibre network to generate the fixed interface.

[0111] Some such methods of sequentially forming the layers (e.g. vacuum filtration), require pre-fabrication of the fibres at a pre-determined diameter. In such cases, the person skilled in the art will be aware that there are many ways in which to form fibres of a pre-determined diameter.

[0112] In one embodiment, the at least one substrate comprises: a metal, a conducting polymer and / or conductive polymer composite, PET / ITO, fluorine-doped tin oxide (FTO), transparent conductive oxides, and mixtures thereof. The substrate may be an electrode, which may be in any form, such as a foil or a tape. Examples of possible electrodes include, but are not limited to: copper tape, aluminium tape, carbon tape, ITO / PET, ITO / glass, FTO / glass, or mixtures thereof.

[0113] The present disclosure also provides for a laminate material produced according to a method described herein.

[0114] The present disclosure also provides for a method of manufacturing a triboelectric generator, the method comprising:• arranging a first generator element and a second generator element in an arrangement such that relative movement between the generator elements generates a potential difference between them due to a triboelectrification effect, wherein:• the first generator element comprises a first laminate material, wherein the first laminate material is or comprises at least one laminate composition according to any one of claims X to X; and• the second generator element comprises a second laminate material, wherein the second laminate materials is or comprises at least one laminate composition according to any one of claims X to X, wherein the first laminate material and the second laminate material are arranged on the first generator element and the second generator element such that relative movement of the first and second generator elements can cause the first laminate material to come in to contact with the second laminate material,wherein the contact between one the first laminate material and the second laminate material generates electricity.

[0115] In one embodiment, the method further comprises:• connecting an external electrical circuit as described herein to a first electrode as defined herein that is in contact with a first side of the arrangement of the first and second generator elements.

[0116] Upon application of vibrations or compressive force to the laminate material, current flow is induced in the electrode (e.g. metallic foil) which can be captured and used for diverse applications.

[0117] In one embodiment, the method further comprises:• connecting the external electrical circuit to a second electrode that is in contact with a second side of the arrangement of the first and second generator elements.

[0118] In some embodiments, the circuit is connected between the first electrode and the second electrode. In this two-electrode mode, relative movement of the first and second generator elements generates electricity by induction on both of the electrodes.

[0119] In some embodiments, the first electrode is the substrate upon which the arrangement of the first and second generator elements is deposited, and the second electrode is in contact with the opposing top side of the arrangement of the first and second generator elements.

[0120] The present disclosure also provides for a triboelectric generator produced according to a method described herein.

[0121] The present disclosure also provides for a use of at least one laminate material as described herein in the manufacture of a triboelectric generator.

[0122] The present disclosure also provides for a use of at least one laminate material as described herein, in the manufacture of a triboelectric generator as described herein.Triboelectric Generator

[0123] Disclosed herein is a triboelectric generator comprising one or more laminate compositions as described herein.

[0124] Also disclosed herein is a triboelectric generator comprising a first generator element and a second generator element, the first and second generator elements being arranged so that relative movement between them generates a potential difference between them due to a triboelectrification effect, wherein:• the first generator element comprises a first laminate material, wherein the first laminate material is or comprises at least one laminate composition as defined herein; and• the second generator element comprises a second laminate material, wherein the second laminate material is or comprises at least one laminate composition as defined herein.

[0125] In one embodiment the first laminate material and the second laminate material are arranged on the first generator element and the second generator element such that relative movement of the first and second generator elements can cause the first laminate material to come in to contact with the second laminate material, wherein the contact between one the first laminate material and the second laminate material generates electricity.

[0126] In one embodiment, at least one relative movement comprises at least one rotation and / or at least one relative linear movement of the first generator element relative to the second generator element. In one embodiment, the relative movement comprises a plurality of rotations and / or relative linear movements of the first generator element relative to the second generator element.

[0127] In one embodiment, at least one relative movement comprises at least one relative linear movement of the first and second generator elements. In one embodiment, the relative movement comprises a plurality of relative linear movements of the first and second generator elements.

[0128] In one embodiment, at least one relative movement comprises at least one rotation of the first generator element relative to the second generator element. In one embodiment, the relative movement comprises a plurality of rotations of the first generator element relative to the second generator element.

[0129] In one embodiment, the triboelectric generator, wherein the first generator element and / or the second generator element comprises at least one electrode, optionally comprised or composed of: copper, aluminium, indium tin oxide (ITO), polyethylene terephthalate (PET), fluorine-doped tin oxide (FTO). The electrode may be in any form, such as a foil or a tape. Examples of possible electrodes include, but are not limited to: copper tape, aluminium tape, carbon tape, ITO / PET, ITO / glass, FTO / glass, or mixtures thereof.

[0130] In one embodiment the triboelectric generator comprises one or more of: electrodes as defined herein, to harvest charge via induction; and an external circuit, to use the harvested charge. The external circuit may comprise one or more of: a LED, a battery / capacitor, a voltmeter, an ammeter, and mixtures thereof.

[0131] In one embodiment the triboelectric generator comprises an external electrical circuit to extract the generated electricity.Methods and Uses

[0132] The present disclosure also provides for methods of generating electricity via the triboelectrification effect.Also disclosed herein is a method of generating electricity via the triboelectrification effect, the method comprising:• disposing a first laminate material as defined herein on a first generator element; and• disposing a second laminate material as defined herein on a second generator element, and applying one or more forces such that the first laminate material and second laminate material oscillate between contacting and separating.

[0133] In one embodiment, at least one of the first generator element and / or the second generator element is or comprises an electrode.

[0134] The present disclosure also provides for a method of generating electricity with a triboelectric generator described herein, the method comprising:• exerting and releasing pressure along at least one axis one or more times, such that the first laminate material and second laminate material oscillate between contacting and separating;• exerting a tortional force one or more times such that the first laminate material and second laminate material oscillate between contacting and separating; or• a mixture thereof.

[0135] In one embodiment, the contacting the first laminate material and the second laminate material, comprises applying a pressure so that at least a portion of a surface of the first laminate material and at least a portion of surface of the second laminate material contact, and then releasing the pressure so that the first laminate material and the second laminate material separate to induce a charge transfer.

[0136] In one embodiment, the contacting the first laminate material and the second laminate material, comprises applying a pressure so that at least a portion of a surface of the first laminate material and at least a portion of surface of the second laminate slide against one another to induce a charge transfer.Substrates and Articles

[0137] The present disclosure also provides for a substrate comprising at least one laminate material as described herein, or a triboelectric generator as described herein.

[0138] There is no particular limitation as to substrates that are suitable for comprising the laminate material or triboelectric generator. A suitable substrate may be any substrate to which the laminate material or triboelectric generator may be affixed or integrated. Substrates may be described in terms of function and / or constitutive material.

[0139] In one embodiment, the substrate is selected from: wearable electronics (e.g. smart clothing, fitness trackers, health monitoring devices), portable electronics (e.g. mobile phones, tablets, portable chargers), self-powered sensors (e.g. environmental sensors, motion detectors, pressure sensors), medical devices (e.g. implantable sensors, pacemakers, health monitoring patches or devices), energy harvesting devices (e.g. harvesting tiles, backpack generators, bicycle dynamos), smart home devices (e.g. smart switches, remote controls, smart doorbells), automotive electronics (e.g. vehicles, tires, car seats, dashboards), robotics, consumer electronics (e.g. game controllers, smart watches), public infrastructure (e.g. smart roads, energy harvesting benches, pedestrian sensors) and combinations thereof.

[0140] In one embodiment, the substrate is selected from: metals, alloys, woods, plastics, polymers, ceramics, composites, glass, semiconductors, biomaterials or textiles.

[0141] In one embodiment, the substrate is a construction material. Suitable examples of construction materials include, but are not limited to, one or more of: concrete, steel, brick, wood, glass, asphalt, cement, plaster, stone, metals such as aluminium, or alloys such as steel, and mixtures thereof.

[0142] In one embodiment, the substrate is a textile. Suitable examples of textiles include, but are not limited to, one or more of: cotton, polyester, wool, silk, nylon, viscose, linen, acrylic, elastane, hemp, and blends or combinations thereof, and mixtures thereof.

[0143] The present disclosure also provides for an article of clothing comprising at least one laminate material as described herein, or a triboelectric generator as described herein. Exemplary articles of clothing include, but are not limited to, one or more of: shirts, singlets, trousers, pants, underwear, hats and headwear, scarves, gloves, socks, jumpers, jackets, robes, costumes, and accessories such as bags, belts, suspenders, neckties and handkerchiefs, and mixtures thereof.

[0144] In one embodiment, the article of clothing is a piece of armour.EXAMPLE EMBODIMENTS

[0145] The present disclosure may be described by one or more of the following example embodiments.1. A laminate composition comprising a plurality of sequentially alternating layers of layer A and layer B, wherein:• layer A comprises a first set of fibres;• layer B comprises a second set of fibres; and• at least a portion of the first set of fibres have a cross-sectional diameter that is about or at least about 2, 3, 4, 5, 6, 7, 8, 9, or 10-times greater than at least a portion of the cross- sectional diameters of the second set of fibres, wherein: at least a portion of the first set of fibres and the second set of fibres comprise the same material; and / or• at least a portion of the second set of fibres in layer B is interwoven with or extends into a portion of the fibres in one or more adjacent, overlaying or underlying layer A.2. The laminate according to example embodiment 1, wherein at least a portion of the first set of fibres in layer A, is interwoven with or extends into, a portion of the fibres in one or more adj acent, overlaying or underlying layer B, to an extent less than that which the at least a portion of the second set of fibres in layer B is interwoven with or extends into a portion of the fibres in one or more adjacent, overlaying or underlying layer A.3. The laminate according to example embodiment 1, wherein there is substantially no interweaving or extension of the first set of fibres in layer A, with the fibres in one or more adjacent, overlaying or underlying layer B.4. The laminate according to example embodiment 1, wherein the percentage of layer B, relative to all layer B within the plurality of sequentially alternating layers, for which least a portion of the second set of fibres therein is interwoven with or extends into a portion of the fibres in one or more adjacent, overlaying or underlying layer A is about or greater than about 75%; and / or wherein the percentage of layer A, relative to all layer A within the plurality of sequentially alternating layers, for which at least a portion of the first set of fibres therein is interwoven with or extends into, a portion of the fibres in one or more adjacent, overlaying or underlying layer B, to an extent less than the extent to which the at least a portion of the second set of fibres in layer B is interwoven with or extends into a portion of the fibres in one or more adjacent, overlaying or underlying layer A, is about or greater than about 75%.5. The laminate according to any one of the preceding example embodiments, wherein: the first set of fibres has a cross-sectional diameter in a range of about 0.50 pm to about 50.00 pm, optionally in a range of about 10 pm to about 20 pm; and the second set of fibres has a cross-section diameter in a range of about 0.05 pm to about 5.00 pm, optionally between about 1 to about 2 pm.6. The laminate according to any one of the preceding example embodiments, wherein at least a portion of the first set of fibres have a cross-sectional diameter of about, or at least about 10-times at least a portion of the cross-sectional diameters of the second set of fibres.7. The laminate according to any one of the preceding example embodiments, wherein the radius of curvature of at least a portion of the fibres in the second set of fibres is about 10% of the radius of curvature of at least a portion of fibres in the first set of fibres.8. The laminate according to any one of the preceding example embodiments, wherein at least a portion of the first set of fibres have a larger variation in aspect ratio along a length of the first set of fibres in comparison to at least a portion of the second set of fibres.9. The laminate according to any one of the preceding example embodiments, wherein at least about 75 wt% of one or more layer A comprises the first set of fibres.10. The laminate according to any one of the preceding example embodiments, wherein at least about 75 wt% of one or more layer B comprises the second set of fibres.11. The laminate according to any one of the preceding example embodiments, wherein one or more layer A consists essentially of the first set of fibres.12. The laminate according to any one of the preceding example embodiments, wherein one or more layer B consists essentially of the second set of fibres.13. The laminate according to any one of the preceding example embodiments wherein the laminate comprises at least one other layer of material in addition to one or more layer A and one or more layer B.14 The laminate material according to any one of the preceding example embodiments, wherein the first set of fibres and / or the second set of fibres comprise a material selected from: a dielectric material, a ferroelectric material, an elastomer, a thermoplastic, and mixtures thereof.15. The laminate material according to any one of the preceding example embodiments, wherein the first set of fibres and / or the second set of fibres comprise a dielectric material, optionally selected from: polystyrene, silk, polycaprolactone, polylactic acid, ethyl vinyl acetate, polyvinylidene difluoride (and associated co-polymers), and mixtures thereof.16. The laminate material according to any one of the preceding example embodiments, wherein the first set of fibres and / or the second set of fibres comprise polystyrene.17. The laminate material according to any one of the preceding example embodiments, wherein the first set of fibres and / or the second set of fibres comprise foamed polystyrene.18. The laminate material according to any one of the preceding example embodiments, wherein the first set of fibres and / or the second set of fibres comprise poly vinylidene difluoride (and associated co-polymers).19. The laminate material according to any one of the preceding example embodiments, wherein the first set of fibres and / or the second set of fibres comprise a recycled material.20. The laminate material according to any one of the preceding example embodiments, comprising a total of at least 10 layers of layer A and layer B.21. The laminate material according to any one of the preceding example embodiments, wherein:• one or more layer A’s; and / or• one or more layer B’s further comprise as least one excipient selected from: fillers, or self-assembled monolayers, and mixtures thereof.22. The laminate material according to any one of the preceding example embodiments, wherein at least a portion of the first set of fibres and / or the second set of fibres are produced by one or more techniques selected from: electrospinning, interfacial polymerisation, freeze- drying synthesis, template synthesis, self-assembly, phase separation, spinneret-based tunable engineered parameter, drawing, printing, lay-by-layer deposition, dip coating, pin coating, melt blowing, or a combination thereof.23. The laminate material according to any one of the preceding example embodiments, wherein at least a portion of the first set of fibres and / or the second set of fibres is produced by electrospinning.24. A triboelectric generator comprising a first generator element and a second generator element, the first and second generator elements being arranged so that relative movement between them generates a potential difference between them due to a triboelectrification effect, wherein:• the first generator element comprises a first laminate material, wherein the first laminate material is or comprises at least one laminate composition according to any one of example embodiments 1 to 23; and• the second generator element comprises a second laminate material, wherein the second laminate materials is or comprises at least one laminate composition according to any one of example embodiments 1 to 23, wherein the first laminate material and the second laminate material are arranged on the first generator element and the second generator element such that relative movement of the first and second generator elements can cause the first laminate material to come into contact with the second laminate material, wherein the contact between one the first laminate material and the second laminate material generates electricity.25. The triboelectric generator according to example embodiment 24, wherein the relative movement comprises relative linear movement of the first and second generator elements.26. The triboelectric generator according to example embodiment 24 or example embodiment 25, wherein the relative movement comprises rotation of the first generator element relative to the second generator element.27. The triboelectric generator according to any one of example embodiments 24 to 26, wherein the triboelectric generator, wherein the first generator element and / or the second generator element comprises at least one electrode, optionally comprised or composed of , a conducting polymer and / or conductive polymer composite, PET / ITO, fluorine-doped tin oxide (FTO), transparent conductive oxides, and mixtures thereof.28. The triboelectric generator according to any one of example embodiments 24 to 27, further comprising at least one of an external electrical circuit to extract the generated electricity.29. A method of generating electricity via the triboelectrification effect, the method comprising:• disposing a first laminate material as defined according to any one of example embodiments 1 to 23 on a first generator element; and• disposing a second laminate material as defined according to any one of example embodiments 1 to 23 on a second generator element,and applying one or more forces such that the first laminate material and second laminate material oscillate between contacting and separating.30. The method according to example embodiment 29, wherein at least one of the first generator element and / or the second generator element is or comprises an electrode.31. A method of generating electricity with the triboelectric generator according to any one of example embodiments 24 to 28, the method comprising:• exerting and releasing pressure along at least one axis one or more times, such that the first laminate material and second laminate material oscillate between contacting and separating;• exerting a tortional force one or more times such that the first laminate material and second laminate material oscillate between contacting and separating; or• a mixture thereof.32. The method according to example embodiment 31, wherein the contacting the first laminate material and the second laminate material, comprises applying a pressure so that at least a portion of a surface of the first laminate material and at least a portion of surface of the second laminate material contact, and then releasing the pressure so that the first laminate material and the second laminate material separate to induce a charge transfer.33. The method according to example embodiment 31 or example embodiment 32, wherein the contacting the first laminate material and the second laminate material, comprises applying a pressure so that at least a portion of a surface of the first laminate material and at least a portion of surface of the second laminate slide against one another to induce a charge transfer.34. A substrate comprising at least one laminate material according to any one of example embodiments 1 to 23, or a triboelectric generator according to any one of 24 to 28.35. The substrate according to example embodiment 34, wherein the substrate is selected from: metals, alloys, woods, plastics, polymers, ceramics, composites, glass, semiconductors, biomaterials, textiles, and combinations thereof.36. The substrate according to example embodiment 34 or example embodiment 35, wherein the substrate is a construction material.37. The substrate according to any one of example embodiments 34 to 36, wherein the substrate is a textile.38. An article, optionally an article of clothing comprising at least one laminate material according to any one of example embodiments 1 to 23, or a triboelectric generator according to any one of 24 to 28.39. The article according to example embodiment 38, wherein the article is a piece of armour.40. A method of manufacturing a laminate material, optionally a laminate material according to any one of example embodiments 1 to 23, the method comprising:• deposition of a first set of fibres on at least one substrate;• deposition of a second set of fibres to form a first interface;• deposition of a further group of the first set of fibres on the second set of fibres to form a second interface, wherein at least a portion of the first set of fibres have a cross-sectional diameter that is about or at least about 2, 3, 4, 5, 6, 7, 8, 9, or 10-times greater than at least a portion of the cross-sectional diameters of the second set of fibres.41. The method according to example embodiment 40, wherein the first interface is a fixed interface, and the second interface is a non-fixed interface.42. The method according to example embodiment 40 or example embodiment 41, wherein the deposition of the second set of fibres on top of the first set of fibres, comprises the use of electric fields on pressure.43. The method according to any one of example embodiments 40 to 42, further comprising sequential repetition of the steps of: deposition of a second set of fibres as described herein, on top of the first set of fibres, to form an interface; and deposition of the first set of fibres on the second set of fibres to form an interface.44. The method according to any one of example embodiments 40 to 43, the method comprising electrospinning, vacuum filtration, or spray coating.45. The method according to any one of example embodiments 40 to 44, the method comprising electrospinning.46. The method according to any one of example embodiments 40 to 45, wherein the at least one substrate comprises: a metal, a conducting polymer, PET / ITO, fluorine-doped tin oxide (FTO), or mixtures thereof.47. A laminate material produced according to the method of any one of example embodiments 40 to 46.48. A method of manufacturing a triboelectric generator, optionally a triboelectric generator according to any one of example embodiments 24 to 28, the method comprising:• arranging a first generator element and a second generator element in an arrangement such that relative movement between the generator elements generates a potential difference between them due to a triboelectrification effect, wherein:• the first generator element comprises a first laminate material, wherein the first laminate material is or comprises at least one laminate composition according to any one of example embodiments 1 to 23; and• the second generator element comprises a second laminate material, wherein the second laminate materials is or comprises at least one laminate composition according to any one of example embodiments 1 to 23, wherein the first laminate material and the second laminate material are arranged on the first generator element and the second generator element such that relative movement of the first and second generator elements can cause the first laminate material to come in to contact with the second laminate material, wherein the contact between one the first laminate material and the second laminate material generates electricity.49. The method of example embodiment 48, the method further comprising:• connecting an external circuit to a first electrode that is in contact with a first side of the arrangement of the first and second generator elements.50. The method of example embodiment 48 or example embodiment 49, the method further comprising:• connecting the external circuit to a second electrode that is in contact with a second side of the arrangement of the first and second generator elements.51. A triboelectric generator produced according to the method of any one of example embodiments 48 to 50.52. Use of at least one laminate material according to any one of example embodiments 1 to 23, in the manufacture of a triboelectric generator.53. Use of at least one laminate material according to any one of example embodiments 1 to 23, in the manufacture of a triboelectric generator according to any one of example embodiments 24 to 28.EXAMPLES

[0146] The present disclosure may be described by one or more of the following examples.General Characterisation MethodsScanning Electron Microscopy

[0147] Scanning electron microscopy (SEM) of the rPS laminates was performed by sputtercoating a 4 nm gold layer onto the laminate surface, followed by imaging using an FEI Nova NanoSEM 650 field-emission SEM (The Netherlands) at an operating voltage of 5-10 kV. Samples were sputter-coated (Cressington 208HRD, Watford, UK) for 30 s using an Au target in an Ar atmosphere with a current of 80 mA, resulting in a 4 nm thick coating. SEMCryo-Ion Mill and Helium Ion Microscopy

[0148] The rPS laminate cross sections were prepared by cryo-ion milling in a Leica EM TIC3X (Germany). Samples were mounted directly onto copper holders using copper adhesive tape and then cooled down to -150 °C before milling with a triple argon ion beam at 5 keV for 30 min. Helium ion microscopy (HIM) was performed on a Zeiss ORION NanoFab (Germany) using a 30 keV helium ion beam at a typical beam energy and current of 30 keV and 0.5 pA, respectively. No conductive coating was necessary for this imaging; instead, in situ charge neutralisation by a low-energy electron flood gun was used.Fiber Diameter Analysis

[0149] The average fiber diameter was calculated from the SEM images using the Gwyddion 2.53 software program Brno, Czech Republic). More than 100 fibreswere counted from at least 3 SEM images which were taken from different places on a sample.Coherent anti-Stokes Raman Scattering Microscopy (CARS)

[0150] CARS was performed on an Olympus FV3000 laser-scanning confocal microscope (Japan) under femtosecond laser excitation. The tunable (792 nm, CARS pump wavelength) and fixed (1045 nm, CARS Stokes wavelength) outputs of a dual-output Ti: sapphire femtosecond laser (Spectra Physics InSight X3, USA) focused onto coverslip-mounted samples using a silicone-oil-immersion 30* objective with enhanced near-infrared transmittance (Olympus UPLSAPO30XSIR, Japan). The overlap between the pump and the Stokes beam was adjusted with a motorised delay line (Newport DL125, USA). Motorised variable attenuators were used to reduce the power of both beams to 10% of the laser output power. The backward (epi-) CARS signal at 638 nm, corresponding to the polystyrene Raman band at 3058 cm-1, was optically filtered through short pass (690 SP) and band-pass (600 / 50) filters and collected with a time-correlated single photon counting detector (PicoQuant Hybrid PMA, Germany) synchronised with the excitation laser.Peel Testing

[0151] The 180° peel tests were performed on individual bilayers of small-diameter PS fibres electrospun on large-diameter PS fibres, and large-diameter PS fibres electrospun on smalldiameter PS fibres with peeling at 100 mm min-1and sample size 10 x 10 mm.Electromechancial Testing: Piezoelectric Mode

[0152] The electromechanical response of triboelectric laminates (TLs) was tested using a dynamic test Instron El 000 instrument, which provided a constant pressing force and frequency. The samples were cut into pieces with dimensions of 1.5 x 1.5 cm. These samples were tested via cyclic compression at a frequency of 1 Hz, and with lower and upper force limits of 2 and 12 N. The EOc and / scwere measured using a Keithley 6514 electrometer (USA) connected to a PicoScope 5444B oscilloscope (UK). To eliminate friction, the samples were adhered to indium-tin-oxide-coated glass slides using double-sided adhesive carbon tape (P77817-20, Science Services Gmb).Electromechanical Testing: TENG Mode

[0153] The triboelectric measurements were made under controlled conditions — a separation distance of 5 mm, a pressing force of IO N, and a contact-separation frequency of 1 Hz. To ensure repeatability, contact separation was carried out using an Instron El 000 material testing machine (USA). The generated current signals were measured using a Keithley 6514 electrometer (USA) connected to a PicoScope 5444B PC oscilloscope system (UK). For highspeed contact separation, a pneumatic device from custom-made programmable logic controller controlled (Mitsubishi AL2-24MR-D) the pneumatic system. A low friction smooth cylinder actuator (SMC MQML10) capable of producing 16 N contacting force and high translation speed (730 mm s-1) was used, with a separation distance of 35 mm. A Faraday cage was placed around the triboelectric testing area to eliminate parasitic signals. All samples were measured in constant ambient relative humidity (35%).Electromechanical Testing: Response to Airflow

[0154] To measure the electromechanical response to airflow, a custom testing rig was developed to vary air pressure incident on the PS laminates. This rig used two with an inner diameter of 1.5 mm with each nozzle was placed on different sides of the sample. One nozzle was stationary at 4 cm from the sample centre while the other nozzle was moved from the sample centre to 15 mm from the sample edge. The total displacement was 38 mm, at a frequency of 14-15 Hz. The moving nozzle was located 20 mm away from the sample surface. The laminate sample with attached Al electrode films was mounted in the plastic frame with an open area of 40 * 15 mm. The Al electrode, exposed to the moving nozzle, was perforated using a needle with a diameter of 0.3 mm. The hole density was 20 holes cm-2.Capacitor Charging

[0155] The AC signal from a TENG was rectified using a full bridge rectifier and then directed to a capacitor. The voltage across the capacitor was measured using a Keithley 6514 electrometer (USA) connected to a PicoScope 5444B PC oscilloscope (UK). Energy E (nJ), stored in the capacitor, was calculated using the Equation E = 0.5CV2, where C is the capacitance of the capacitor (0.47 pF) and V is the voltage across the capacitor (V).Example 1: Preparation of Electrospun Recycled PS Nanofibers and Laminates

[0156] To obtain a foamed polystyrene (FPS) solution (10 wt%), 1 g of FPS was dissolved in mixture of 1.215 mL THF and 8.345 mL DMF solution with the addition of 0.0338 g of sodium chloride (NaCl) and mixed at room temperature using a magnetic stirring at 500 rpm for24 hours. To obtain an FPS solution (30 wt%) 3 g of FPS was dissolved in a mixture of 0.954 mL THF and 6.490 mL DMF solution with the addition of 0.039 g of NaCl and mixed at room temperature using a magnetic stirring at 500 rpm for 24 hours. The mixtures with 10 wt% and 30 wt% FPS were electrospun using needle electrospinning equipment at room temperature in constant ambient relative humidity (35%). The solutions were transferred to a 2 mL plastic syringe fitted with a needle (21 G, outer diameter 0.8 mm) and set up in the electrospinning apparatus. A grounded piece of aluminium foil was located 16 cm away from the capillary tip and used as a collector. The electric potential was controlled at 15 kV. For the FPS (10 wt%) solution, the flow rate was 0.1 mL h-1, and for the FPS (30 wt%), the flow rate was 1.2 mL h-1. By alternating the feedstock solution between 10 and 30 wt% FPS solution a layer-by-layer assembly of laminate structure was produced. The parameters to produce laminates of a given thickness are shown in Table 1.Table 1. Parameters for electrospinning recycled polystyrene (rPS) laminates.* Samples were used for interfacial adhesion and microscopic characterisation only, electromechanical characterisation not shown.

[0157] Images of the raw FPS material and its dissolution are shown in Figure 1, along with the distribution of fibre diameters obtained from the 10 wt% (approximately 200 nm) and 30 wt% (approximately 2000 nm), and SEM images of the electrospun rPS small and large- diameter fibres.

[0158] By alternating the feedstock solution between 10 and 30 wt% FPS solution a layer-by- layer assembly of laminate structure was produced (Figures 2 and 3).

[0159] To create a ‘fixed’ interface, the 200 nm diameter fibres were electrospun on a mat of 2000 nm diameter fibres. These 200 nm diameter fibres were found to penetrate the existing pore network of the 2000 nm diameter fiber layer and thus have strong interfacial adhesion. In contrast, a ‘slip’ interface was created when 2000 nm diameter fibres were electrospun onto a densely packed array of 200 nm diameter fibres. Here, the 2000 nm diameter fibres could not penetrate the pores of the 200 nm diameter fiber layer, only sitting on the surface and thus having a poor interlayer adhesion.

[0160] To quantify the difference in adhesion, a vertical peel test was performed according to the general method described above (Figure 4). When 2000 nm diameter fibres were electrospun on a fiber layer consisting of 200 nm diameter fibres, the average interlayer adhesion was measured as 0.018 ± 0.009 mN, with a maximum adhesive force of 0.039 mN. In contrast, when the 200 nm diameter fibres were electrospun on a fiber layer consisting of 2000 nm diameter fibres, the average adhesion was threefold larger at 0.06 ± 0.02 mN, with a maximum adhesive force of 0.12 mN. This difference between interfacial adhesive force enabled slip to preferentially occur between large-diameter fibres electrospun on top of smalldiameter fibres.

[0161] Controlling the formation of the slip and fixed interfaces, led to the recycled polystyrene (rPS) laminate demonstrating an electromechanical response. When a three-bilayer rPS laminate was tested under cyclic compression testing, a clear current and voltage response was observed (Figure 5, image (a)) — showing electricity production from motion from purely polystyrene interfaces. Manually assembling three-bilayer laminates with misaligned interfaces produced no electrical response from the cyclic compression testing (Figure 5, image (b)). Similarly, manually assembling six layers of fibres (thus eliminating fixed interfaces) resulted in negligible electrical production (Figure 5, image (c)). In comparison, the creation of alternating fixed-slip interfaces resulted in a 122* -fold enhancement in voltage output compared to an equivalent assembly with no fixed interfaces.

[0162] To understand how the introduction of a fixed interface led to mechanical-to-electrical energy conversion, the polarity across multiple interfaces was considered. As the rPS laminate is compressed, there is slip between large and small fibres and the slip interface, generating negative charge on large, smooth fibres and positive charge on small fibres, creating a triboelectric dipole. As the force is released and reapplied, the oscillating dipoles lead to the measured voltage output, represented schematically in Figure 6, images (a) and (b). When nofixed interface is introduced, into the rPS laminate (by manual assembly of individual layers), this charging phenomena occurs on both sides of each small and each large layer. In this case, the internal dipoles fully cancel out and no external electricity can be harvested from the rPS laminate.

[0163] Confocal anti-Stokes Raman spectroscopy (CARS) was used to visualise the internal interfaces within a rPS laminate (Figure 6, image (c)). The CARS volume maps revealed a clear transition between an interface containing mixed small- and large-diameter fibres and a layer of large-diameter fibres, providing clear evidence of the intermixing between small- and large- diameter fibres across the fixed interface (Figure 6, image (c)).Example 2: Scaling of rPS Laminates as pseudo-piezoelectric materials

[0164] To maximise energy-harvesting performance, rPS laminate structures were scaled from 3 bilayers up to 30 bilayers (60 layers) with the same total thickness of -300 pm. The 30- bilayer structure was chosen as the maximum layer number (to maximise generated surface charge) maintains a 300 pm thickness while containing 2000 ± 500 nm fibres.

[0165] Cyclic compressive testing of the 30-bilayer laminate (Figure 7, image (a)) was performed to assess the electromechanical response of the rPS laminate. These tests were performed in contact or “piezoelectric” mode (Figure 7, image (b)), where there is no separation between the mechanical tester and sample during cyclic compression. This is achieved by applying a preload force, in this case 2 N, with the testing load (AF = 10 N) applied to measure electromechanical response. The peak-to-peak short-circuit current (Isc) was measured 6.1 ± 0.2 nA (Figure 8, image (a)) while the peak-to-peak open-circuit voltage (Voc) was measured to be 23.5 ± 0.1 V (Figure 8, image (b)). The peak-to-peak voltage output of 23.5 V is comparable, or higher, than equivalent voltage outputs from state-of-the-art fluoropolymer piezoelectric nanogenerators with an equivalent 10 N of force.

[0166] The applicability of the rPS laminates as a vibrational energy harvester was demonstrated by varying air pressure air applied onto the rPS laminate (Figure 9). The air pressure on one side of the laminate was oscillated at 14-15 Hz between the edge and centre of the rPS laminate, while on the back side, the air pressure was kept in a constant location. When this experiment was performed on a dense polystyrene film, negligible current was measured (<0.005 pA) (Figure 9, image (b)); however, the 30-bilayer rPS laminate showed >2 pA of current, which was constant over 40000 cycles (Figure 9, image (c)).Example 3: Scaling of rPS Laminates for TENGs

[0167] Vertical contact-separation mode TENG testing was performed through contactseparation experiments between two individual laminate samples (Figure 10, image (a) and (b)). By changing the electrospinning order, the contact interface between the two 30-bilayer samples was altered to demonstrate the importance of contact alignment (Figure 10, image (c)). These tests, performed in a precisely controlled manner with 0.1 m s-1separation speed at 10 N maximum force, showed that by altering the contact interface from misaligned (large fiber vs large fiber or small fiber vs small fiber) to aligned (large fiber vs small fiber), an order of magnitude increase in current and voltage was observed Figure 10, image (c)) and Table 2.Table 2. Comparison of electromechanical conversion from contact-separation between two 30-bilayer rPS laminates with different contact interfaces, tested in vertical contact-separation TENG mode

[0168] The aligned interface sample showed a peak-to-peak voltage of 135 ± 3 V (at 1 G load resistance) and a / Sc of 268 ± 7 nA. This aligned interface can be considered analogous to using inversely polarized fluoropolymers in a TENG configuration

[0169] To demonstrate the full potential of rPS as a mechanical energy-harvesting material, contact-separation tests were performed at high speeds, up to 0.73 m s-1, analogous to the walking speed of many patients requiring wearable electronics and sensors. These tests resulted in an increase in measured peak-to-peak voltage to 200 ± 30 V and a further order of magnitude increase in / Sc up to 12000 ± 500 nA. This corresponds to a peak power density of 77.4 mW m-2at a 100 M load resistance (Figure 11, image (a)). Further, mechanical energy harvesting between two 30-bilayer rPS samples achieved charging of a 0.47 pF capacitor to 15 V in 200 s, reaching 1 V in 8 s (Figure 11, image (b)).Example 3. Poly(vinylidene-difluoride) laminates

[0170] Poly(vinylidene-difluoride) laminates were produced using an analogous electrospinning method described in Example 1, and characterised in accordance with the above-described general characterisation methods.

[0171] Fibre size for the small and large fibres was determined to be on average, 80nm and 800nm respectively (Figure 12, image (a)). Conversion of mechanical compression to current and voltage output was examined for a (left) a 5-bilayer laminate; and (right) a 15-bilayer laminate (Figure 12, images (b) and (c)). Figure 12, image (d) depicts the force curves used to obtain the data for current and voltage - with the key point being the use of ION of force here.

[0172] It will be appreciated by persons skilled in the art that numerous variations and / or modifications may be made to the above-described embodiments, without departing from the broad general scope of the present disclosure. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive.

Claims

1. CLAIMS1. A laminate composition comprising a plurality of sequentially alternating layers of layer A and layer B, wherein:• layer A comprises a first set of fibres;• layer B comprises a second set of fibres; and• at least a portion of the first set of fibres have a cross-sectional diameter that is about or at least about 2, 3, 4, 5, 6, 7, 8, 9, or 10-times greater than at least a portion of the cross- sectional diameters of the second set of fibres, wherein at least a portion of the first set of fibres and the second set of fibres comprise the same material, and wherein optionally at least a portion of the second set of fibres in layer B is interwoven with or extends into a portion of the fibres in one or more adjacent, overlaying or underlying layer A.

2. The laminate according to claim 1, wherein at least a portion of the first set of fibres in layer A, is interwoven with or extends into, a portion of the fibres in one or more adjacent, overlaying or underlying layer B, to an extent less than that which the at least a portion of the second set of fibres in layer B is interwoven with or extends into a portion of the fibres in one or more adjacent, overlaying or underlying layer A.

3. The laminate according to claim 1, wherein there is substantially no interweaving or extension of the first set of fibres in layer A, with the fibres in one or more adjacent, overlaying or underlying layer B.

4. The laminate according to claim 1, wherein the percentage of layer B, relative to all layer B within the plurality of sequentially alternating layers, for which least a portion of the second set of fibres therein is interwoven with or extends into a portion of the fibres in one or more adjacent, overlaying or underlying layer A is about or greater than about 75%; and / or wherein the percentage of layer A, relative to all layer A within the plurality of sequentially alternating layers, for which at least a portion of the first set of fibres therein is interwoven with or extends into, a portion of the fibres in one or more adjacent, overlaying or underlying layer B, to an extent less than the extent to which the at least a portion of the second set of fibres in layer B is interwoven with or extends into a portion of the fibres in one or more adjacent, overlaying or underlying layer A, is about or greater than about 75%.

5. The laminate according to any one of the preceding claims, wherein: the first set of fibres has a cross-sectional diameter in a range of about 0.50 pm to about 50.00 pm, optionally in a range of about 10 pm to about 20 pm; and the second set of fibres has a cross-section diameter in a range of about 0.05 pm to about 5.00 pm, optionally between about 1 to about 2 pm.

6. The laminate according to any one of the preceding claims, wherein at least a portion of the first set of fibres have a cross-sectional diameter of about, or at least about 10-times at least a portion of the cross-sectional diameters of the second set of fibres.

7. The laminate according to any one of the preceding claims, wherein the radius of curvature of at least a portion of the fibres in the second set of fibres is about 10% of the radius of curvature of at least a portion of fibres in the first set of fibres.

8. The laminate according to any one of the preceding claims, wherein at least a portion of the first set of fibres have a larger variation in aspect ratio along a length of the first set of fibres in comparison to at least a portion of the second set of fibres.

9. The laminate according to any one of the preceding claims, wherein at least about 75 wt% of one or more layer A comprises the first set of fibres.

10. The laminate according to any one of the preceding claims, wherein at least about 75 wt% of one or more layer B comprises the second set of fibres.

11. The laminate according to any one of the preceding claims, wherein one or more layer A consists essentially of the first set of fibres.

12. The laminate according to any one of the preceding claims, wherein one or more layer B consists essentially of the second set of fibres.

13. The laminate according to any one of the preceding claims wherein the laminate comprises at least one other layer of material in addition to one or more layer A and one or more layer B.14 The laminate material according to any one of the preceding claims, wherein the first set of fibres and / or the second set of fibres comprise a material selected from: a dielectric material, a ferroelectric material, an elastomer, a thermoplastic, and mixtures thereof.

15. The laminate material according to any one of the preceding claims, wherein the first set of fibres and / or the second set of fibres comprise a dielectric material, optionally selected from: polystyrene, silk, polycaprolactone, polylactic acid, ethyl vinyl acetate, polyvinylidene difluoride (and associated co-polymers), and mixtures thereof.

16. The laminate material according to any one of the preceding claims, wherein the first set of fibres and / or the second set of fibres comprise polystyrene.

17. The laminate material according to any one of the preceding claims, wherein the first set of fibres and / or the second set of fibres comprise foamed polystyrene.

18. The laminate material according to any one of the preceding claims, wherein the first set of fibres and / or the second set of fibres comprise poly vinylidene difluoride (and associated copolymers).

19. The laminate material according to any one of the preceding claims, wherein the first set of fibres and / or the second set of fibres comprise a recycled material.

20. The laminate material according to any one of the preceding claims, comprising a total of at least 10 layers of layer A and layer B.

21. The laminate material according to any one of the preceding claims, wherein:• one or more layer A’s; and / or• one or more layer B’s further comprise as least one excipient selected from: fillers, or self-assembled monolayers, and mixtures thereof.

22. The laminate material according to any one of the preceding claims, wherein at least a portion of the first set of fibres and / or the second set of fibres are produced by one or more techniques selected from: electrospinning, interfacial polymerisation, freeze-drying synthesis, template synthesis, self-assembly, phase separation, spinneret-based tunable engineered parameter, drawing, printing, lay-by-layer deposition, dip coating, pin coating, melt blowing, or a combination thereof.

23. The laminate material according to any one of the preceding claims, wherein at least a portion of the first set of fibres and / or the second set of fibres is produced by electrospinning.

24. A triboelectric generator comprising a first generator element and a second generator element, the first and second generator elements being arranged so that relative movement between them generates a potential difference between them due to a triboelectrification effect, wherein:• the first generator element comprises a first laminate material, wherein the first laminate material is or comprises at least one laminate composition according to any one of claims 1 to 23; and• the second generator element comprises a second laminate material, wherein the second laminate materials is or comprises at least one laminate composition according to any one of claims 1 to 23, wherein the first laminate material and the second laminate material are arranged on the first generator element and the second generator element such that relative movement of the first and second generator elements can cause the first laminate material to come into contact with the second laminate material, wherein the contact between one the first laminate material and the second laminate material generates electricity.

25. The triboelectric generator according to claim 24, wherein the relative movement comprises relative linear movement of the first and second generator elements.

26. The triboelectric generator according to claim 24 or claim 25, wherein the relative movement comprises rotation of the first generator element relative to the second generator element.

27. The triboelectric generator according to any one of claims 24 to 26, wherein the triboelectric generator, wherein the first generator element and / or the second generator element comprises at least one electrode, optionally comprised or composed of , a conducting polymer and / or conductive polymer composite, PET / ITO, fluorine-doped tin oxide (FTO), transparent conductive oxides, and mixtures thereof.

28. The triboelectric generator according to any one of claims 24 to 27, further comprising at least one of an external electrical circuit to extract the generated electricity.

29. A method of generating electricity via the triboelectrification effect, the method comprising:• disposing a first laminate material as defined according to any one of claims 1 to 23 on a first generator element; and• disposing a second laminate material as defined according to any one of claims 1 to 23 on a second generator element, and applying one or more forces such that the first laminate material and second laminate material oscillate between contacting and separating.

30. The method according to claim 29, wherein at least one of the first generator element and / or the second generator element is or comprises an electrode.

31. A method of generating electricity with the triboelectric generator according to any one of claims 24 to 28, the method comprising:• exerting and releasing pressure along at least one axis one or more times, such that the first laminate material and second laminate material oscillate between contacting and separating;• exerting a tortional force one or more times such that the first laminate material and second laminate material oscillate between contacting and separating; or• a mixture thereof.

32. The method according to claim 31, wherein the contacting the first laminate material and the second laminate material, comprises applying a pressure so that at least a portion of a surface of the first laminate material and at least a portion of surface of the second laminate material contact, and then releasing the pressure so that the first laminate material and the second laminate material separate to induce a charge transfer.

33. The method according to claim 31 or claim 32, wherein the contacting the first laminate material and the second laminate material, comprises applying a pressure so that at least a portion of a surface of the first laminate material and at least a portion of surface of the second laminate slide against one another to induce a charge transfer.

34. A substrate comprising at least one laminate material according to any one of claims 1 to 23, or a triboelectric generator according to any one of 24 to 28.

35. The substrate according to claim 34, wherein the substrate is selected from: metals, alloys, woods, plastics, polymers, ceramics, composites, glass, semiconductors, biomaterials, textiles, and combinations thereof.

36. The substrate according to claim 34 or claim 35, wherein the substrate is a construction material.

37. The substrate according to any one of claims 34 to 36, wherein the substrate is a textile.

38. An article, optionally an article of clothing comprising at least one laminate material according to any one of claims 1 to 23, or a triboelectric generator according to any one of 24 to 28.

39. The article according to claim 38, wherein the article is a piece of armour.

40. A method of manufacturing a laminate material, optionally a laminate material according to any one of claims 1 to 23, the method comprising:• deposition of a first set of fibres on at least one substrate;• deposition of a second set of fibres to form a first interface;• deposition of a further group of the first set of fibres on the second set of fibres to form a second interface, wherein at least a portion of the first set of fibres have a cross-sectional diameter that is about or at least about 2, 3, 4, 5, 6, 7, 8, 9, or 10-times greater than at least a portion of the cross-sectional diameters of the second set of fibres.

41. The method according to claim 40, wherein the first interface is a fixed interface, and the second interface is a non-fixed interface.

42. The method according to claim 40 or claim 41, wherein the deposition of the second set of fibres on top of the first set of fibres, comprises the use of electric fields on pressure.

43. The method according to any one of claims 40 to 42, further comprising sequential repetition of the steps of: deposition of a second set of fibres as described herein, on top of the first set of fibres, to form an interface; and deposition of the first set of fibres on the second set of fibres to form an interface.

44. The method according to any one of claims 40 to 43, the method comprising electrospinning, vacuum filtration, or spray coating.

45. The method according to any one of claims 40 to 44, the method comprising electrospinning.

46. The method according to any one of claims 40 to 45, wherein the at least one substrate comprises: a metal, a conducting polymer, PET / ITO, fluorine-doped tin oxide (FTO), or mixtures thereof.

47. A laminate material produced according to the method of any one of claims 40 to 46.

48. A method of manufacturing a triboelectric generator, optionally a triboelectric generator according to any one of claims 24 to 28, the method comprising:• arranging a first generator element and a second generator element in an arrangement such that relative movement between the generator elements generates a potential difference between them due to a triboelectrification effect, wherein:• the first generator element comprises a first laminate material, wherein the first laminate material is or comprises at least one laminate composition according to any one of claims 1 to 23; and• the second generator element comprises a second laminate material, wherein the second laminate materials is or comprises at least one laminate composition according to any one of claims 1 to 23, wherein the first laminate material and the second laminate material are arranged on the first generator element and the second generator element such that relative movement of the first and second generator elements can cause the first laminate material to come in to contact with the second laminate material, wherein the contact between one the first laminate material and the second laminate material generates electricity.

49. The method of claim 48, the method further comprising:• connecting an external circuit to a first electrode that is in contact with a first side of the arrangement of the first and second generator elements.

50. The method of claim 48 or claim 49, the method further comprising:• connecting the external circuit to a second electrode that is in contact with a second side of the arrangement of the first and second generator elements.

51. A triboelectric generator produced according to the method of any one of claims 48 to 50.

52. Use of at least one laminate material according to any one of claims 1 to 23, in the manufacture of a triboelectric generator.

53. Use of at least one laminate material according to any one of claims 1 to 23, in the manufacture of a triboelectric generator according to any one of claims 24 to 28.

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