False eyelash device and method of manufacturing thereof

Abstract

Described is a false eyelash device comprising at least one false eyelash, wherein the at least one false eyelash comprises: a liquid crystal polymer (LCP); and a first photothermal additive; wherein the first photothermal additive allows for photothermal actuation of the LCP by generating heat in the at least one false eyelash upon photoexcitation of the first photothermal additive, and wherein the at least one false eyelash is configured to deform between a non-actuated state and an actuated state upon photothermal actuation of the LCP. Also described is a method of manufacturing said false eyelash device.

Description

[0001] FALSE EYELASH DEVICE AND METHOD OF MANUFACTURING THEREOF

[0002] TECHNICAL FIELD OF THE INVENTION

[0003] The invention pertains to a false or artificial eyelash device adding functionality to eyelashes beyond mere fashion. The invention further relates to a method of manufacturing the false eyelash device.

[0004] BACKGROUND OF THE INVENTION

[0005] The present invention tackles a practical challenge for people looking to remain fashionable in the presence of (sun)light, in particular strong (sun)light, without having to squint or use undesirable accessories, such as an umbrella, hat or caps for instance. Such traditional solutions to block or hinder the incidence of strong (sun)light are undesirable as they would overshadow the original style the user may be aiming for.

[0006] It has been proposed to use false or artificial eyelashes. For instance, CA2939672 Al discloses a set of false eyelashes and a method for application these onto the natural eyelashes of a wearer, as commonly used in the beauty industry. The false eyelash device uses a band onto which a plurality of either mink, silk, synthetic or real hair lashes is attached. These lashes curl upward to mimic the natural curvature of eyelashes in order to extend the natural eyelashes. The band is curved to mimic the curvature of the eyelid. The eyelash device has an adhesive strip provided on an anterior / top part of the band and is applied under the natural eyelashes on the eyelid.

[0007] It would be desirable to provide a wearable artificial eyelash device that is able to provide functionality beyond just fashion. For instance, it would be desirable to provide a (sun)light screening functionality to the eyelash device, which functionality does not depend on the use of any auxiliary accessories, such as a cap. Also, it would be desirable to provide the functionality without having to perform any specific action to provide the functionality.

[0008] SUMMARY OF THE INVENTION

[0009] It is an object of the invention therefore to provide a wearable artificial eyelash device that is able to provide functionality beyond just fashion. A further aim is to provide a (sun)light screening functionality to the eyelash device, which functionality does not depend on the use of any auxiliary accessories, such as a cap. Yet another aim is to provide the functionality without having to perform any specific action to provide the functionality. According to a first aspect of the invention, this and other aims are provided by a false eyelash device comprising at least one false eyelash, wherein the at least one false eyelash comprises:

[0010] - a liquid crystal polymer (LCP); and

[0011] - a first photothermal additive; wherein the first photothermal additive allows for photothermal actuation of the LCP by generating heat in the at least one false eyelash upon photoexcitation of the first photothermal additive, and wherein the at least one false eyelash deforms from a non-actuated state to an actuated state upon the photothermal actuation of the LCP.

[0012] The LCP used in the false eyelash device is able to deform, such as bend, into different forms depending on the light intensity that reaches it, shielding the users eyes from (sun)light in highlight conditions. How much light is blocked can be adjusted, and the angle of our material to the user’s eyes means that the user’s line-of-sight is not substantially blocked. Indeed, only light coming into the eye from a relatively high angle is blocked. The invented false eyelash device may also be reusable several times.

[0013] Without being limited thereto, the present invention addresses the problems of the prior art by applying a liquid crystal polymer, preferably a low-temperature liquid crystal oligomer network (LCON) material, as a base for attached eyelash accessories. Such material may be tailored to have similar mechanical properties and colour options as regular eyelash accessories, yet, with the additional ability of responsive actuation with stimuli, such as incident light. Therefore, the inventive responsive LCP attachable eyelash wearables can be configured to deform above a certain threshold intensity of light into a form that would shield light from entering the eyes of the user. The used LCP material may be synthesized in different formulations that would allow a different transmission of light through the LCP material, allowing the light-shielding properties of the eyelash device to act between partially and completely blocking light from reaching a user’s eyes. Moreover, a final angle of the invented eyelash device provided on a user’s eyes in ‘blocking mode’ would only block light coming from a relatively high angle, thus not affecting a regular line-of-sight of the user. This may allow a user to retain his or her fashion preferences even in debilitating environment high-light conditions. The functionality provided by the LCP material is inherent to its properties, and the eyelash device as claimed therefore does not require any driving electronics or configuration apart from incident light. It is therefore a device that is plug-and-play.

[0014] According to a second aspect of the invention, there is provided a method of manufacturing a false eyelash device, the method comprising providing a liquid crystal material, adding a first photothermal additive, and consolidating the mixture to obtain at least one false eyelash comprising a liquid crystal polymer (LCP) and the photothermal additive.

[0015] The invented method may involve mixing reactive mesogens with other chemicals to form a base LCP material. Further, in suitable embodiments, a dye may be added to integrate colour as well as introduce the ability to heat the LCP material with light. A preferred dye may also be selected to change colour with light as well. The LCP material may then be partially polymerized in a suitable mould to create a preliminary, short-eyelash preform. To endow the eyelash device with its transformative capability and an ‘eyelash curl’ , it may then be stretched to a significant extend and exposed to UV light, which solidifies its structure in said elongated state and aligns the reactive mesogens in a specific direction. This alignment is important for the LCP material's ability to change shape between an non-actuated state and an actuated state, as will be elucidated further hereinbelow.

[0016] When sufficient light intensity reaches the wearable eyelash device, the incident light induces heating of the device up to a temperature of for instance 50°C, at which temperature the eyelash device may be straightened from a curled non-activated state to a more straightened activated state to block a substantial amount of light from reaching the users eyes. The thermal conductivity of the LCP material is preferably selected to be sufficiently low to reduce the risk of burning, even at temperatures as high as 50°C. The heat produced in the LCP material resulting from incident light causes mesogenic molecules to shift out of their orderly state and cause the LCP material, and therefore also the false eyelash device to change shape.

[0017] DETAILED DESCRIPTION OF THE INVENTION

[0018] The invention as disclosed above in summary will now be elucidated further hereinbelow.

[0019] According to the first aspect of the invention, there is provided a false eyelash device comprising at least one false eyelash, wherein the at least one false eyelash comprises:

[0020] - a liquid crystal polymer (LCP); and

[0021] - a first photothermal additive; wherein the first photothermal additive allows for photothermal actuation of the LCP by generating heat in the at least one false eyelash upon photoexcitation of the first photothermal additive, and wherein the at least one false eyelash is configured to deform between a non-actuated state and an actuated state upon photothermal actuation of the LCP. The first photothermal additive may be provided as such or may be mixed with the LCP, which is preferred. The amount of the first photothermal additive may be selected by a skilled person in order to be able to allow for photothermal actuation of the LCP by generating heat in the at least one false eyelash upon photoexcitation of the first photothermal additive.

[0022] The present invention provides a solution to the limitations encountered in functions of fashion accessories, especially in more inconvenient environmental conditions. For instance, in high-light- intensity conditions, the use of additional accessories such as an umbrella, hat or cap or sunglasses are typically required in the art. Such traditional solutions do not preserve the initial desired fashion of the user. The LCP material used in the invented eyelash device solves this problem by changing the shape of the eyelashes to shield the eyes of the user in case of high-light conditions, without obstructing the line-of-sight of the user by blocking only high-incident-angle light. The invented eyelash device comprising the LCP material does not need any computational control: the incidence of light on the LCP material will cause a photothermal effect with the added first photothermal additive. The actuation of the LCP material is reversible in that the LCP material will return to its original state if the incident light-intensity decreases below a threshold light-intensity. Such a threshold light-intensity may for instance be around 20 mW / cm2, and may depend on the specific LCP material used. The application of the invented eyelash device to the natural eyelashes of a user may employ adhesive methods known in the art, meaning that there is no barrier to use for users. Moreover, the insulating properties of the LCP material ensure that the LCP material and the eyelash device is safe to touch during operation.

[0023] Liquid crystal polymers (LCPs) are polymers with the property of liquid crystal, typically containing aromatic rings as mesogens. According to the invention, non-crosslinked LCP’s may be used. However, polymeric materials like liquid crystal elastomers (LCE) and liquid crystal networks (LCN) which also exhibit liquid crystallinity are preferred. LCE and LCN are both crosslinked LCP albeit have different cross link density. LCN are primarily synthesized from (meth)acrylate-based multifunctional monomers while LCE usually come from crosslinked polysiloxanes. The invention preferably uses LCN as LCP material.

[0024] The LCP may comprise main chain liquid crystal polymers (MCLCP) having liquid crystal cores in the main chain, or, by contrast, may comprise side chain liquid crystal polymers (SCLCP) (also) have pendant side chains containing liquid crystal cores.

[0025] Liquid crystalline monomers are the precursors of polymer networks that may retain liquid crystallinity. The properties of the polymer networks prepared by the polymerization (homo- or copolymerization) of these typically difunctional liquid crystalline monomers are primarily defined by the degree of crosslinking (e.g., the molecular weight between crosslinks) as well as the strength of intermolecular interaction derived from the liquid crystalline precursor(s).

[0026] The LCP according to the invention may be prepared by using liquid crystalline monomers based on l,4-Bis[4-(n-acryloyloxybutyloxy)benzoyloxy]-2-methylbenzene, also referred to as CnM. In these LCP, n may be selected from 3-11, such as from 3 to 6, also referred to as C3M or C6M, the C6M monomer being preferred. For example, in some embodiments, the mesogenic core comprises CnM having three aromatic rings. In one non-limiting example, the mesogenic core is C6M or C3M, though the value of n in CnM may vary from 3 to 11. The LCP may comprise a mesogenic core, preferably formed by the polymerization of acrylate groups, more preferably formed by the polymerization of at least one of 2-methyl-l,4-phenylene bis[4-[[6- (acryloyloxy) hexyl] oxy] benzoate] and 4-methoxyphenyl 4-((6-(acryloyloxy) hexyl)oxy)benzoate.

[0027] The LCP according to the invention may also be prepared by using liquid crystalline monomers having a mesogenic core, wherein the mesogenic core comprises 4-(6-(acryloyloxy)n-oxy)phenyl- 4-(6-(acryloyloxy)m-oxy)benzoate (also referred to as CnBAPE). In some embodiments, n is one of pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, and m is one of pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, the C6BAPE monomer being preferred. These mesogenic cores include two benzyl rings only, which significantly decreases the energy required to induce the actuation of the LCP. In some embodiments, CnBAPE is any of C5BAPE, C6BAPE, C7BAPE, C8BAPE, C9BAPE, C10BAPE or C11BAPE.

[0028] In a preferred embodiment, a mixture of CnM and CnBAPE monomers is used as a monomer mixture in preparing the LCP, LCN or LCE. A mixture of C6M and C6BAPE monomers is more preferred.

[0029] The mesogenic content of the LCP having monomers based on two different mesogenic cores preferably have a molar ratio of monomers having the CnBAPE mesogenic core to monomers having the CnM mesogenic core that ranges from 0.5:0.5 to 0.9:0: 1 molar ratio, more preferably from 0.6:0.4 to 0.8:0.2 molar ratio, even more preferred from 0.65:0:35 to 0.75:0.25 molar ratio.

[0030] In a preferred embodiment, the LCE may furthermore comprise a vinyl inclusion. The inclusion of a vinyl may be used for tuning the actuation temperature, particularly for lowering it. In a preferred embodiment, a molecule with two aromatic rings may be used, which may lower the actuation temperature to around 30-40 degrees Celsius. Alternatively, molecules with three aromatic rings may be used. The resulting actuation temperature would in that case be around 80-90 degrees Celsius. As disclosed above, a mixture of both types of molecules may be optimal.

[0031] It is known to use an azo-Michael (AM) addition reaction with primary amines to carry out an oligomerization reaction with monomers having CnBAPE mesogenic cores for instance to thereby form an LCE with increased flexibility or a liquid crystal oligomer network (LCON). The oligomerization reaction may be triggered with light when incorporating a latent photoinitiator. In another method, a thiol-Michael (TM) addition reaction is used. Like with the AM addition reaction, this approach uses oligomerization of liquid crystalline monomers having CnBAPE mesogenic cores for instance and a second reaction to complete the crosslinking of the materials to prepare the LCE. Suitable thiol monomers such as GDMP, BDMT, TMPTMP, PETMP, or any combination thereof may be used. It should be mentioned that the LCP used in the invented eyelash device preferably does not use an AM or TM reaction to prepare the LCP, since such AM or TM reactions tend to produce a LCP (specifically a LCE) having a less preferred too high flexibility.

[0032] According to an embodiment of the invention, a false eyelash device is provided wherein in the non-actuated state the at least one false eyelash is substantially curved and wherein in the actuated state the at least one false eyelash is substantially straight. Due to the substantially curved position of the at least one eyelash in the non-actuated state, light may be able to enter an eye of a user wearing the eyelash device. Indeed, the eyelash device is applied in such a position to an eyelid of a user that the at least one eyelash will be in an upwardly curved position with respect to the users eye. Due to the substantially straight position of the at least one eyelash in the actuated state, light may not be able to enter an eye of a user wearing the eyelash device. Indeed, the eyelash device is applied in such a position to an eyelid of a user that the at least one eyelash will be in a downwardly straight position with respect to the users eye.

[0033] According to another embodiment, an eyelash device is provided wherein the deforming between the non-actuated state and the actuated state and vice versa comprises straightening and bending of the at least one false eyelash.

[0034] According to yet another embodiment, a false eyelash device is provided wherein a mesogen alignment direction of the LCP extends parallel to a direction in which the at least one false eyelash extends. This direction will, in a state in which the eyelash device is attached to the eye of a user, extend away from the eye of the user, i.e. will extend in the direction in which natural eyelashes of the user extend. The at least one eyelash of the eyelash device preferably has sufficient rigidity in order to prevent it from blocking the user’s vision in a non-actuated state. In suitable embodiments, a modulus of elasticity of the at least one false eyelash is between 20 MPa and 3 GPa.

[0035] A particularly useful embodiment of the invention relates to an eyelash device wherein the at least one false eyelash further comprises a dye for providing the at least one false eyelash with a preferred colour. Even more preferred is an embodiment wherein the dye is a second photothermal additive, and wherein the second photothermal additive allows for changing the colour of the at least one false eyelash upon photoexcitation of the second photothermal additive.

[0036] An efficient embodiment of the eyelash device creating a combination of several functions is characterized in that the first photothermal additive and the second photothermal additive are the same photothermal additive. Referring to ‘the photothermal additive’ in the context of the present application encompasses referring to the ‘first photothermal additive’, to the ‘second photothermal additive’ or two a combination of both. In an embodiment having the second photothermal additive, the added dye supplies both colour and allows the LCP material to actuate and fulfil its function. The second photothermal additive provides colour selection and exotic colour changing functions with lighting, in particular when based on cholesteric materials.

[0037] An embodiment of the invention therefore relates to an eyelash device wherein the photothermal additive is a cholesteric dopant, preferably comprising a photo switchable dye such as a spiropyran (SP). More preferably, a nitro-substituted SP is used, such as a nitrobenzopyrylospiran. Suitable nitrobenzopyrylospirans may include but are not limited to l,3,3-trimethylindolino-6'- nitrobenzopyrylospiran and / or l-(2-hydroxyethyl)-3,3-dimethylindolino-6’-nitrobenzopyrylospiran.

[0038] One skilled in the art may select the amount of the photothermal additive according to his needs. In preferred embodiments, the at least one false eyelash comprises between 0 and 5 wt.% of said photothermal additive, more preferably between 1 and 4 wt.% of said photothermal additive, even more preferably between 1.5 and 3 wt.% of said photothermal additive.

[0039] In order to function in an environment wherein sunlight may act as driving agent for the LCP function, a suitable embodiment provides a device wherein a threshold photon energy for photoexcitation of the first photothermal additive is within the solar irradiance spectrum on the Earth’s surface. According to the invention, the first photothermal additive allows for photothermal actuation of the LCP by generating heat in the at least one false eyelash upon photoexcitation of the first photothermal additive, which causes the at least one false eyelash to deform from a non-actuated state to an actuated state upon the photothermal actuation of the LCP.

[0040] An embodiment therefore provides a device wherein the at least one false eyelash is in the nonactuated state if a temperature of the at least one false eyelash is smaller than a mesogenic core transition temperature of the LCP and is in the actuated state if the temperature of the at least one false eyelash is equal to or greater than the mesogenic core transition temperature of the LCP.

[0041] The mesogenic core transition temperature may preferably range from 30-70 °C, more preferably from 35-60 °C, and most preferably from 37-50 °C.

[0042] In another embodiment of the device, the at least one false eyelash is in the non-actuated state if an incident irradiance is smaller than a threshold irradiance which results in the LCP temperature being smaller than the mesogenic core transition temperature, and to be in the actuated state if the incident irradiance is equal to or larger than the threshold irradiance which results in the LCP temperature being equal to or greater than the mesogenic core transition temperature, the threshold irradiance preferably corresponding to the solar irradiance on the Earth’s surface at a preferred cloud condition, the threshold irradiance more preferably being 200 W / m2. This threshold irradiance corresponds to about 80% blockage of light intensity on cloudy days.

[0043] A preferred cloud condition comprises any one or more of a preferred cloud cover, preferred cloud type, preferred cloud base and preferred cloud height, wherein preferably the incident irradiance smaller than the predefined irradiance corresponds to cloudy conditions and the incident irradiance equal to or larger than the predefined irradiance corresponds to sunny conditions.

[0044] The eyelash device may be free-standing or may be combined with natural eyelashes of a user. According to an embodiment, a device is provided further comprising a base to which a first end of the at least one false eyelash is attached and wherein a second end of the at least one false eyelash extends substantially away from the base. The at least one eyelash may be one eyelash only, or may be embodied as a plurality of eyelashes, such as from 2-20 for instance.

[0045] A useful embodiment provides a device wherein the base is configured to be adherable to an eyelid of a user, the base preferably being conformed to the eyelid of the user, the base more preferably being conformed to an upper eyelid of the user. In order to adhere the base to an eyelid of a user, a device according to an embodiment further comprises an adhesive layer and wherein the base is configured to be adherable to an eyelid of the user using the adhesive layer, the adhesive layer preferably comprising a cyanoacrylate-based glue.

[0046] The invention also relates to an eyelash device as disclosed herein in all its embodiments, wherein the device is adhered to an eyelid of a user. In such an adhered state, an embodiment provides a device wherein the at least one false eyelash is configured to, in the non-actuated state allow incident light to enter an eye of the user when an incident angle of the light is smaller than a first threshold angle; and at least partially prevent incident light from entering the eye of the user when the incident angle of the light is equal to or greater than the first threshold angle.

[0047] Yet another embodiment relates to a device wherein the at least one false eyelash is configured to, in the actuated state allow incident light to enter an eye of the user when an incident angle of the light is smaller than a second threshold angle; at least partially prevent incident light from entering the eye of the user when the incident angle of the light is equal to or greater than the second threshold angle, wherein the second threshold angle is smaller than the first threshold angle.

[0048] Yet another embodiment relates to a device wherein light with an incident angle equal to the first threshold angle is outside of a monocular visual field of the eye of the user or wherein light with an incident angle equal to the first threshold angle is within peripheral vision of the user, preferably outside of near-peripheral vision, more preferably outside of near-peripheral and mid-peripheral vision.

[0049] More preferably, a device according to an embodiment is characterized in that light with an incident angle equal to the second threshold angle is located within a monocular visual field of the eye of the user, preferably within peripheral vision of the user.

[0050] According to a second aspect of the invention, a method of manufacturing a false eyelash device is provided, the method comprising providing a liquid crystal material, adding a first photothermal additive, and shaping and consolidating the mixture to obtain at least one false eyelash comprising a liquid crystal polymer (LCP) and the photothermal additive.

[0051] The LCP synthesis method in an embodiment tailors a two-step crosslinking process to mould material into the shape of curled eyelashes. The shape is applied during moulding, and a curl of the eyelashes is introduced during mechanical stretching for alignment of the mesogen core. In an embodiment, the LCP eyelash device is collectively strained to a strain of for instance 200% to achieve curl and function. Materials such as LCON and LCN may be used as LCP.

[0052] In a useful embodiment of the method, a method is provided wherein providing the liquid crystal material comprises partially polymerizing the liquid crystal material of the mixture in a suitable mould, stretching the partially polymerized liquid crystal material before cross-linking and thereafter cross-linking the liquid crystal material to obtain an aligned LCP. Another embodiment relates to a method wherein cross-linking the liquid crystal material is carried out by photocuring with UV-light.

[0053] Another embodiment provides a method further comprising attaching the at least one false eyelash to a base.

[0054] In yet another embodiment, a method is provided further comprising providing the base with an adhesive layer.

[0055] The invented eyelash device is responsive and therefore revolutionary for the fashion world. The use of functional smart materials such as the LCP for fashion and wearables has a potential for applications ranging from surface haptics to environmental adaptability.

[0056] Suitable embodiments of the invented false eyelash device as disclosed herein may change its colour or shape with lighting conditions, as well as provide convenience for the user with its light shielding abilities. This is advantageous in creating desired fashion effects in inconvenient environmental conditions, such as in high-light conditions, while adding an effect of dynamism with the movement and colour-change abilities.

[0057] The invented false eyelash device may also be advantageous for users wishing to apply such fashion accessories during (outdoor) sporting activities, where (sun)light shielding may be of great importance. In such outdoor activities, the device is particularly useful as it does not block the line- of-sight of a user while it blocks high-intensity, high-incident angle light.

[0058] The invented false eyelash device may also be used as a safety device, protecting the user’s eyesight in dangerously high-light conditions. BRIEF DESCRIPTION OF THE FIGURES

[0059] Examples of the invention will now be elucidated with reference to the following figures, without however being limited thereto. In the figures:

[0060] Figures 1A-B schematically show a schematic perspective view of a false eyelash device in a nonactuated state and in an actuated state, respectively, in accordance with an embodiment of the invention.

[0061] Figure 2A-C show chemical formulae of exemplary constituents of a liquid crystal polymer, a photothermal additive and a photoinitiator, respectively, in accordance with embodiments of the invention.

[0062] Figures 3A-B schematically show a schematic side view of the false eyelash device in a nonactuated state and in an actuated state when being adhered to an eyelid of a user, respectively, in accordance with an embodiment of the invention.

[0063] Figure 4 shows a flowchart of a method of manufacturing the false eyelash device, in accordance with an embodiment of the invention.

[0064] Figure 5 shows a flowchart of a method of manufacturing the false eyelash device, in accordance with an embodiment of the invention.

[0065] Figure 6 shows a flowchart of a method of manufacturing the false eyelash device, in accordance with an embodiment of the invention.

[0066] DESCRIPTION OF EXEMPLARY EMBODIMENTS

[0067] FIG. 1 schematically shows a schematic perspective view of a false eyelash device (100) in a nonactuated state and in an actuated state, in accordance with an embodiment of the invention.

[0068] Referring to FIG. 1A, it shows the false eyelash device (100) in the non-actuated state, according to an embodiment of the invention. The false eyelash device (100) comprises at least one false eyelash (110). In the specific embodiment of FIG. 1A, the false eyelash device (100) comprises a plurality of false eyelashes (110). A first end of each eyelash (110) may be attached to a base (120), while a second end of each eyelash (110) may extend in a direction substantially away from the base (120). In the non-actuated state, the false eyelashes (110) are substantially curved.

[0069] The base (120) may be configured to be adherable to an eyelid of a user. To this end, the base (120) may be provided with an adhesive layer (130), which may comprise a cyanoacrylate based glue. Additionally, the base (120) may be conformed to the eyelid of the user. Preferably, the base (120) may be conformed to an upper eyelid of the user. The at least one eyelash (110) comprises a liquid crystal polymer (LCP). The LCP comprises mesogenic cores. The non-actuated state of the false eyelash device (100) corresponds to a state of the LCP in which the mesogenic cores are aligned. This is schematically shown in the right-hand side of FIG. 1A.

[0070] Referring to FIG. IB, it shows the false eyelash device (100) in the actuated state, according to an embodiment of the invention. The false eyelash device (100) in the actuated state comprises the same constituents as in the non-actuated state shown in FIG. 1A. Microscopically, the difference of the actuated with respect to the non-actuated state corresponds to the fact that the mesogenic cores of the LCP are not aligned. The disorder in the mesogenic cores may be introduced by an increased temperature with respect to the temperature at which the mesogenic cores are aligned. The disordered state of mesogenic cores is schematically shown in the left-hand side of FIG. IB.

[0071] In order to be able to introduce heat to the false eyelash (110) for increasing the temperature, the false eyelash (110) furthermore comprises a photothermal additive. The photothermal additive allows for photothermal actuation of the LCP by generating heat in the false eyelash upon photoexcitation of the first photothermal additive.

[0072] Macroscopically, the difference between the two states becomes evident from the different shape of the false eyelashes (110). Whereas the false eyelashes (110) in FIG. 1A are substantially curved, the false eyelashes (110) in FIG. IB are substantially straight. The advantages of the false eyelashes (110) being straightened upon transitioning from the non-actuated to the actuated state become particularly apparent when the false eyelash device (100) is worn by a user, which will be elaborated upon with reference to FIG. 3.

[0073] FIG. 2 shows chemical formulae of exemplary constituents of the LCP, a photothermal additive and a photoinitiator, in accordance with embodiments of the invention.

[0074] Referring to FIG. 2A, it shows two structural formulas of two different molecules containing acrylate groups. The top molecule corresponds to 2-methyl-l,4-phenylene bis[4-[[6 (acryloyloxy )hexyl] oxy] benzoate]. The bottom molecule corresponds to 4-methoxyphenyl 4-((6- (acryloyloxy)hexyl)oxy)benzoate. Both molecules may be used as monomers in a polymerization process, which in a preferred embodiment results in the LCP used in the false eyelash (110). Referring to FIG. 2B, it shows a structural formula of l-(2-hydroxyethyl)-3,3-dimethylindolino-6'- nitrobenzopyrylospiran. This dopant may be a constituent of the false eyelash (100) and may be used as the photothermal additive for photothermal actuation of the LCP in a preferred embodiment of the invention. It is considered to induce cholesteric effects with a twisting power molecule.

[0075] Referring to FIG. 2C, it shows a structural formula of bis(2,4,6-trimethylbenzoyl) phenylphosphine oxide. In a preferred embodiment, this molecule may act as a photoinitiator under the influence of UV-light for the solidification of the LCP, after stretching it and after aligning the mesogenic cores.

[0076] FIG. 3 schematically shows a schematic side view of the false eyelash device (100) in a nonactuated state and in an actuated state when being adhered to an eyelid (210) of a user, in accordance with an embodiment of the invention.

[0077] Referring to FIG. 3 A, it shows the false eyelash device (100) in the non-actuated state when being worn by a user. The false eyelash device (100) is adhered to the eyelid (210) of the eye (200). In the specific embodiment of FIG. 3 A, the false eyelash device (100) is adhered to an upper eyelid (211) of the user. In this way, the false eyelash device (100) may optimally shield the eye of the user from directly incident light from above, such as sunlight or other artificial light sources. It should be noted, however, that in a different embodiment the false eyelash device (100) may be adhered to a bottom eyelid (212) of the eye (200).

[0078] The false eyelash device (100) of FIG. 3 A is in the non-actuated state. As mentioned before with reference to FIG. 1A, macroscopically this corresponds to a state in which the false eyelashes are curved. The cloud in the figure indicates that, in a preferred embodiment, the false eyelash device (100) is in the non-actuated state under cloudy weather conditions.

[0079] A solid line is defined perpendicular to the eye (200) of the user. This line represents the normal, with respect to which the angle of incidence of light incident to the eye (200) will be defined in a two-dimensional space. The monocular field of view of the human eye in reality is defined by a three-dimensional space. However, since the false eyelash device (100) primarily shields the eye from incident light above it, a two-dimensional field of view is assumed in which only the polar angle 9 of a spherical coordinate system is considered, while the azimuthal angle is neglected. The angle 9 defines a vertical range of the field of view of the eye (200). An effective vertical range of the field of view of the eye (200) is then defined as that part of the vertical range of the field of view of the eye (200) which is completely unobstructed by the plurality of false eyelashes (110).

[0080] In FIG. 3A, a first threshold angle is defined which corresponds to the maximum angle at which incident light is able to reach the eye (200) without being obstructed in the non-actuated state. At angles greater than the first threshold angle the incident light is at least partially obstructed. It should be noted that the false eyelash device (100) itself may or may not be within the monocular field of view when in the non-actuated state. In the latter case, the at least partially obstructed incident light would not have entered the eye (200) even in absence of the false eyelash device (100). A second threshold angle 02 is incorporated in FIG. 3A for reference and will be further explained with respect to FIG. 3B.

[0081] Referring to FIG. 3B, it shows the false eyelash device (100) in the actuated state when being worn by a user. The false eyelash device (100) is again adhered to the eyelid (210) of the eye (200). In the specific embodiment of FIG. 3B, the false eyelash device (100) is adhered to an upper eyelid (211) of the user. In this way, the false eyelash device (100) may optimally shield the eye of the user from directly incident light from above, such as sunlight or other artificial light sources. It should be noted, however, that in a different embodiment the false eyelash device (100) may be adhered to a bottom eyelid (212) of the eye (200).

[0082] The false eyelash device (100) of FIG. 3B is in the actuated state. As mentioned before with reference to FIG. IB, macroscopically this corresponds to a state in which the false eyelashes are straight. The sun in the figure indicates that, in a preferred embodiment, the false eyelash device (100) is in the actuated state under sunny weather conditions.

[0083] In a similar fashion as in FIG. 3A, a solid line is defined in FIG. 3B perpendicular to the eye (200) of the user representing the normal and a two-dimensional visual field is assumed in which only the polar angle 9 of a spherical coordinate system is considered.

[0084] The second threshold angle 92< 9 is defined as corresponding to the maximum angle at which incident light is able to reach the eye (200) without being obstructed in the actuated state. At angles greater than the second threshold angle 92the incident light is at least partially obstructed. The false eyelash device (100) itself is at least partially within the monocular field of view when in the actuated state. Only then, light that would have entered the eye (200) in absence of the false eyelash device (100) is at least partially obstructed. Consequently, the magnitude of the irradiance or intensity entering the eye (200) is attenuated in case the false eyelash device (100) is in the actuated state.

[0085] FIG. 4 shows a flowchart of a method (300) of manufacturing the false eyelash device (100), in accordance with an embodiment of the invention. Referring to FIG. 4, the method comprises providing (310) a liquid crystal material, adding (320) a first photothermal additive to the liquid crystal material, moulding the obtained mixture in a suitable mould and consolidating (330) the mixture to obtain at least one false eyelash (110) comprising a liquid crystal polymer (LCP) and the photothermal additive. Consolidation of the mixture may involve a photo-polymerization process for curing the liquid crystal material.

[0086] FIG. 5 shows a flowchart of a method (300) of manufacturing the false eyelash device (100), in accordance with a preferred embodiment of the invention. Referring to FIG. 5, it shows a method (300) similar to that of FIG. 4, wherein providing (310) the liquid crystal material comprises adding (311) chain extenders, partially polymerizing (312) the liquid crystal material of the mixture in a suitable mould, stretching (313) the partially polymerized liquid crystal material before cross-linking and thereafter cross-linking (314) the liquid crystal material to obtain aligned LCP. Cross-linking the liquid crystal material may involve photo-polymerization. It should be noted that the method (300) of FIG. 5 may also be performed without performing operation (311). Adding (311) chain extenders or not will affect the cross link density which will finally determine the type of LCP, for example liquid crystal elastomer (LCE), liquid crystal network (LCN) or liquid crystal oligomer network (LCON). It should also be noted that the step (320) of adding a first photothermal additive could, and preferably is, also be performed before the step (312).

[0087] An example of a suitable liquid crystal material is a liquid-crystalline diacrylate 1,4-phenylene bis{4-[6-(acryloyloxy)hexyloxy]benzoate}, which is oriented by stretching and then subjected to a photo-initiated chain crosslinking. The monomer may for instance be uniaxially oriented in its nematic phase. During polymerization, the ordering of the mesogens is frozen-in, yielding a uniaxially crosslinked network. It turned out that the polymerization of the acrylate groups in the mesomorphic phases proceeded relatively fast and to high conversion.

[0088] FIG. 6 shows a flowchart of a method (300) of manufacturing the false eyelash device (100), in accordance with an embodiment of the invention. Referring to FIG. 6, it shows a method (300) similar to that of FIG. 4, further comprising attaching (340) the at least one false eyelash (110) to the base (120) and providing (350) the base (120) with an adhesive layer (130). It should be noted that the optional operations of the method (300) of FIG. 5 and that of the method (300) of FIG. 6 may be combined into an alternative embodiment of the invention.

Claims

CLAIMS1. A false eyelash device (100) comprising at least one false eyelash (110), wherein the at least one false eyelash (110) comprises: a liquid crystal polymer (LCP); and a first photothermal additive; wherein the first photothermal additive allows for photothermal actuation of the LCP by generating heat in the at least one false eyelash upon photoexcitation of the first photothermal additive, and wherein the at least one false eyelash (110) is configured to deform between a non-actuated state and an actuated state upon photothermal actuation of the LCP.

2. A device (100) as claimed in claim 1, wherein in the non-actuated state the at least one false eyelash (110) is substantially curved and wherein the actuated state the at least one false eyelash is substantially straightened.

3. A device (100) as claimed in claim 1 or 2, wherein the deforming between the nonactuated state and the actuated state and vice versa comprises straightening and bending of the at least one false eyelash.

4. A device (100) as claimed in any of the preceding claims, wherein the LCP comprises a crosslinked LCP, preferably any of a liquid crystal network (LCN), a liquid crystal elastomer (LCE) or a liquid crystal oligomer network (LCON).

5. A device (100) as claimed in any of the preceding claims, wherein the LCP comprises a mesogenic core, preferably formed by the polymerization of acrylate groups, more preferably formed by the polymerization of at least one of 2-methyl-l,4-phenylene bis[4-[[6-( acryloyloxy )hexyl] oxy] benzoate] and 4-methoxyphenyl 4-((6-(acryloyloxy)hexyl)oxy)benzoate.

6. A device (100) as claimed in any of claims 1-4, wherein the LCP comprises a mesogenic core, comprising 4-(6-(acryloyloxy) n-oxy)phenyl-4-(6-(acryloyloxy)m-oxy)benzoate, with n being any one of pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, and m being any one of pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, preferably wherein n and m are hexyl.

7. A device (100) as claimed in any of the preceding claims, wherein the LCP comprises a vinyl inclusion.

8. A device (100) as claimed in any of claims 5-7, wherein a mesogen alignment direction of the LCP extends parallel to a direction in which the at least one false eyelash extends.

9. A device (100) as claimed in any of the preceding claims, wherein a modulus of elasticity of the at least one false eyelash (110) is between 20 MPa and 3 GPa.

10. A device (100) as claimed in any of the preceding claims, wherein the at least one false eyelash (110) further comprises a dye for providing the at least one false eyelash (110) with a preferred colour.

11. A device (100) as claimed in claim 10, wherein the dye is a second photothermal additive, and wherein the second photothermal additive allows for changing the color of the at least one false eyelash (110) upon photoexcitation of the second photothermal additive.

12. A device (100) as claimed in claim 11, wherein the first photothermal additive and the second photothermal additive are the same photothermal additive.

13. A device (100) as claimed in claim 12, wherein the photothermal additive is a cholesteric dopant, preferably wherein the photothermal additive is l-(2-hydroxyethyl)-3,3-dimethylindolino- 6'-nitrobenzopyrylospiran, more preferably wherein the at least one false eyelash (110) comprises 2 wt.% of said photothermal additive.

14. A device (100) as claimed in any of the preceding claims, wherein a threshold photon energy for photoexcitation of the first photothermal additive corresponds to a photon energy of light within the solar irradiance spectrum on the Earth’s surface.

15. A device (100) as claimed in any of the preceding claims, wherein the at least one false eyelash (110) is in the non-actuated state if a temperature of the at least one false eyelash (110) is smaller than a mesogenic core transition temperature of the LCP and is in the actuated state if the temperature of the at least one false eyelash (110) is equal to or greater than the mesogenic core transition temperature of the LCP, the mesogenic core transition temperature preferably being between 30-70 °C, more preferably from 35-60 °C, and most preferably from 37-50 °C.

16. A device (100) as claimed in any of the preceding claims, wherein the at least one false eyelash (110) is in the non-actuated state if an incident irradiance is smaller than a threshold irradiance which results in the LCP temperature being smaller than a mesogenic core transitiontemperature, and to be in the actuated state if the incident irradiance is equal to or larger than the threshold irradiance which results in the LCP temperature being equal to or greater than a mesogenic core transition temperature, the threshold irradiance preferably corresponding to the solar irradiance on the Earth’s surface at a preferred cloud condition, the threshold irradiance more preferably being 200 W / m2.

17. A device (100) as claimed in any of the preceding claims, further comprising a base (120) to which a first end of the at least one false eyelash (110) is attached and wherein a second end of the at least one false eyelash (110) extends substantially away from the base.

18. A device (100) as claimed in claim 17, wherein the base (120) is configured to be adherable to an eyelid (210) of a user, the base (120) preferably being conformed to the eyelid (210) of the user, the base (120) more preferably being conformed to an upper eyelid (211) of the user.

19. A device (100) as claimed in claim 17 or 18, further comprising an adhesive layer (130) and wherein the base (120) is configured to be adherable to an eyelid (210) of the user using the adhesive layer (130), the adhesive layer (130) preferably comprising a cyanoacrylate based glue.

20. A device (100) as claimed in any of the preceding claims, wherein the device (100) is adhered to an eyelid (210) of a user.

21. A device (100) as claimed in claim 21, wherein an effective vertical range of a field of view of the eye (200) is smaller in the actuated state when compared to in the non-actuated state, such that the irradiance entering the eye (200) is attenuated in the actuated state when compared to the non-actuated state.

22. A device (100) as claimed in any of the preceding claims, wherein the false eyelash device (100) is located within peripheral vision of the eye (200) of the user, preferably outside of nearperipheral vision, more preferably outside of near-peripheral vision and mid-peripheral vision.

23. A method (300) of manufacturing a false eyelash device (100), the method (300) comprising providing (310) a liquid crystal material, adding (320) a first photothermal additive, and consolidating (330) the mixture to obtain at least one false eyelash (110) comprising a liquid crystal polymer (LCP) and the photothermal additive.

24. A method (300) as claimed in claim 23, wherein providing (310) the liquid crystal material comprises partially polymerizing (312) the liquid crystal material of the mixture in a specialized mould, stretching (313) the partially polymerized liquid crystal material before cross-linking and thereafter cross-linking (314) the liquid crystal material to obtain aligned LCP.

25. A method (300) as claimed in claim 23 or 24, further comprising attaching (340) the at least one false eyelash (110) to a base (120).

26. A method (300) as claimed in claim 25, further comprising providing (350) the base (120) with an adhesive layer (130).

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