[0001] Electronic devices, such as mobile phones, computers, and laptops, may have a keyboard. The keyboard may include a plurality of keys which facilitate in providing input to the electronic device. Accordingly, a user can perform a variety of input operations on the electronic device through the keyboard.

BRIEF DESCRIPTION OF DRAWINGS

[0002] The following detailed description references the drawings, wherein:

[0003] FIG. 1 illustrates a sectional view of a self-healing keyboard, according to an exampie implementation of the present subject matter;

[0004] FIG. 2 illustrates a sectional view of a self-healing keyboard, according to an example implementation of the present subject matter;

[0005] Fig.3 illustrates a sectional view of a self-healing keyboard, according to an example implementation of the present subject matter;

[0006] Fig. 4 illustrates a sectional view of a self-healing film, according to an example implementation of the present subject matter;

[0007] Fig. 5 illustrates a sectional view of a self-healing film, according to an example implementation of the present subject matter;

[0008] Fig. 6 illustrates a method of fabricating a self-healing keyboard of an electronic device, according to an example implementation of the present subject matter; and

[0009] Fig. 7 illustrates a method of fabricating a self-healing keyboard of an electronic device, according to an example implementation of the present subject matter. DETAILED DESCRIPTION

[0010] Electronic devices, such as a personal computer, a laptop, a phone, and a personal digital assistant, include a housing for accommodating various components, such as circuit boards having sensitive electronic components. The electronic devices may also include a keyboard disposed on the housing. The keyboard functions as an input device through which a user can perform a variety of input operations on the electronic device.

[0011] Usually, the keyboards are more prone to wear and tear as the keyboard comes in contact of a user. For example, regular and rough usage of the keyboards may lead to scratches on surface of keys of the keyboards, thereby adversely affecting the appearance and functionality of the keyboards. Moreover, a keyboard may get damaged due to spillage of liquids. Spilled liquids may reach the circuit underneath the keyboard, which may result in electronic components being ruined.

[0012] To protect the keyboards from accidental spillage, the keyboards are coated with a silicone layer. The silicone layer, however, provides poor typing experience and is prone to receive scratch marks on its surface. This may lead to frequent replacement of the silicone layer, thereby imposing additional burden and cost on the users.

[0013] The present subject matter describes keyboards that are waterproof and can heal or repair scratches on their surface on their own. The present subject matter also describes methods of fabricating such keyboards. The present subject matter further describes self-healing films which when applied on keyboards make the keyboards seif-hea!able.

[0014] In accordance with the present subject matter, scratches on the keyboards can heal on their own substantially quickly, for example within 3 seconds, and even at a low temperature of 5 °C. The self-healing property of the keyboards makes them robust, and avoids use and replacement of silicone layers on top, which provides a better user experience of the keyboards. Further, the self-healing films are applied on the keyboards in a continuous manner to cover the keyboards, thereby making the keyboards spill-proof and provide a comfortable typing experience.

[0015| In an example implementation of the present subject matter, a keyboard includes a self-healing film disposed thereon. The self-healing film includes a substrate and a self-heating layer. The self-healing layer is composed of polyurethane, epoxy vinyl ester, epoxy, polyurethane microcapsules filled with silane compound, and a polysiloxane mixture. The polysiloxane mixture may be encapsulated or phase-separated and include pofy-dimethylsiloxane (PDMS) resin, hydroxy end-functkmalized PDMS (HOPDMS), and poly-diethoxysiloxane (PDES), and a combination thereof. The disposal of the self-healing film on the keyboard along with the composition of the self-healing film enables seff-healing and waterproofing of the keyboard.

[0016] The following detailed description refers to the accompanying drawings. Wherever possible, the same reference numbers are used in the drawings and the following description to refer to the same or similar parts. While several examples are described in the description, modifications, adaptations, and other implementations are possible. Accordingly, the following detailed description does not limit the disclosed examples. Instead, the proper scope of the disclosed examples may be defined by the appended claims.

[0017] FIG. 1 illustrates a sectional view of a self-healing keyboard 100, according to an example implementation of the present subject matter. The self- healing keyboard 100 may be implemented in an electronic device, such as a personal computer, a laptop, a phone, a remote control, and a personal digital assistant (PDA).

[0018] The self-healing keyboard 100 includes a self-healing film 102 disposed thereon. The self-healing film 102 is composed of a self-healing layer 104 disposed on a top surface of a keyboard 106. The self-healing layer 104 Is composed of polyurethane, epoxy vinyl ester, and epoxy 108 in the form of a base matrix. The base matrix is embedded with a polysiloxane mixture 110 and polyurethane microcapsules filled with silane compound 112. The polysiloxane mixture 110 includes poly-dimethylsiioxane (PDMS) resin, hydroxy end- functiona!ized PDMS (HOPDMS), and poly-diethoxysiioxane (PDES), and a combination thereof. The polysiioxane mixture 110 may be encapsuiated or phase-separated. The polysiioxane mixture 110 may be encapsuiated using a urea-formaldehyde encapsulation procedure.

[0019J The polyurethane microcapsules may be polyurethane shells filled with silane compound. The silane compound is released when the microcapsules are ruptured due to mechanical damage. The silane compound may be mixed with ch!orobenzene before encapsulating in the polyurethane microcapsules. The polyurethane microcapsules may be formed through an interfacial polymerization procedure.

[0020] in an example implementation, polyurethane in the self-healing layer 104 has a concentration in a range of 60% to 80% by volume, epoxy vinyl ester In the self-healing layer 104 has a concentration in a range of 10% to 15% by volume, and epoxy in the self-healing layer 104 has a concentration in a range of 10% to 15% by volume. Further, the polyurethane microcapsules in the self- healing layer 104 has a concentration in a range of 0.01% to 0.3% by volume, and the polysiioxane mixture in the self-healing layer 104 has a concentration in a range of 1 % to 3% by volume.

[0021] in an example implementation, the self-healing !ayer 104 may have a thickness in a range of about 15 pm to 100 pm. The base matrix of polyurethane, polyester, and epoxy forms an interpenetrating macromofecular network that provides high impact strength, high toughness, and high wear resistance to the self-healing layer 104 and thus to the self-healing keyboard 100. The polysiioxane mixture 110 in the self-healing layer 104 functions as a healing agent, and silane compound, filled in polyurethane microcapsules 112, functions as a coupling agent for polymerization within the self-healing layer 104.

[0022] A scratch on the self-healing keyboard 100 damages the self-healing layer 104, which causes a crack in the base matrix. The crack in the base matrix ruptures the polyurethane microcapsules filled with silane compound 112, which causes silane compound to mix with the polysiloxane mixture 110, poiyurethane, epoxy vinyl ester, and epoxy 108 within the self-healing layer 104. Mixing of silane compound initiates polymerization within the self-healing layer 104 which heals the crack within 3 seconds from the time of scratch and even at a low temperature of 5 °C.

[0023] FIG. 2 illustrates a sectional view of a self-healing keyboard 200, according to an example implementation of the present subject matter. The self- healing keyboard 200 includes a self-healing film 202 disposed over the keyboard 106. The self-healing film 202 includes a substrate 204 and the self-healing layer 104 deposited on the substrate 204, The self-healing layer 104 is the same as the self-healing layer described through the description of FIG. 1. In an example, the substrate 204 is disposed on the keyboard 106 such that the self-healing film 202 interfaces with the keyboard 106 through the substrate 204.

[0024] The substrate 204 is of a material from one of elastomers, polyester, and polycarbonate, or a combination thereof. In an example, the elastomers may include polyisoprene, polybutadiene, chloroprene rubber, butyl rubber, styrene- butadiene rubber, nitrile rubber, hydrogenated nitrile rubbers, ethylene propylene rubber, ethylene propylene dlene monomer (EPDM) rubber, silicone rubber, polyether block amides (PEBA), chlorosuifonated polyethylene, ethylene-vinyl acetate (EVA), polysulfide rubber, thermoplastic urethane, thermoplastic elastomers, or a combination thereof.

[002$] In an example implementation, the substrate 204 may have a thickness in a range of about 25 pm to 900 pm. The self-healing layer 104 is deposited over the substrate 204. The self-healing layer 104 may be coated on the substrate 204 through spray coating. The self-healing layer 104 provides a comfortable typing experience to a user. After coating the self-healing layer 104, the substrate 204 may be heated at a temperature in a range of 60 °C to 150 °C for a time duration in a range of 3 minutes to 60 minutes for curing the self-healing layer 104. Thereafter, the substrate 204 may undergo a molding process to conform a shape of the substrate 204 with a shape of the keyboard on which the substrate 204 is to be disposed. [0026] FIG. 3 illustrates a sectional view of a self-healing keyboard 300, according to an example implementation of the present subject matter. The self- healing keyboard 300 includes a self-healing film 302 disposed over the keyboard 106. The self-healing film 302 includes the self-healing layer 104 attached to the substrate 204 by an adhesive layer 304. The self-healing layer 104 is the same as the self-healing layer described through the description of FIG. 1. The substrate 204 is same as the substrate described through the description of FIG. 2.

[0027] In an example implementation, before coating the adhesive layer 304, a surface of the substrate 204 may be cleaned. Further, the adhesive layer 304 may be coated on the substrate 204 through a spray coating technique, a spin- coating technique, an extrusion coating technique or a lamination technique. The adhesive layer 304 may have a thickness in a range of about 1 pm to 30 pm. The adhesive layer 304 may be a viscoelastic adhesive layer which exhibits both viscous and elastic characteristics when the substrate 204 is disposed over the keyboard 106. In an example, the adhesive layer 304 may include urethane- acrylate, silicone, cyclic olefin copolymer, polyacrylic, polycarbonate, or a combination thereof.

[0028] Once the adhesive layer 304 is coated on the substrate 204, the self- healing layer 104 is deposited on the adhesive layer 304. In an example, the self- healing layer 104 is deposited on the adhesive layer 304 through spray coating.

[0029] FIG.4 illustrates a sectional view of a self-healing film 400, according to an example implementation of the present subject matter. The self-healing film 400 can be disposed on a keyboard of an electronic device, to enable self-healing of the keyboard. A keyboard with the self-healing film 400 pasted on it can self- heal from scratches within 3 seconds from the time of scratch and over a wide temperature range starting from 5 °C.

[0030] The self-healing film 400 includes a self-healing layer 402 coated on a substrate 404. The self-healing layer 402 is the same as the self-healing layer 104 described through the description of FIG. 1. The substrate 404 is same as the substrate described earlier, in an example, the self-healing layer 402 may be coated on the substrate 404 through spray coating. The self-healing layer 402 may have a thickness in a range of about 15 prri to 100 μηι, and includes polyurethane, epoxy vinyl ester, epoxy, polyurethane microcapsules fiiied with si lane compound, and a polysiloxane mixture.

[0031] Fig. 5 illustrates a sectional view of a self-healing film 500, according to an example implementation of the present subject matter. The self-healing film 500, as shown, has an adhesive layer 502 between the self-healing layer 402 and the substrate 404. The self-healing layer 402 is the same as the self-healing layer 104 described through the description of FIG. 1, The adhesive layer 502 is the same as the adhesive layer 304 described through the description of FIG. 3. The self-healing film 500 with the adhesive layer 502 between the self-healing layer 402 and the substrate 404 may be used for keyboards.

[0032] FIG. 6 illustrates a method 600 of fabricating a self-healing keyboard of an electronic device, according to an example implementation of the present subject matter. At block 602 of the method 600, a self-healing iayer is coated on a substrate, where the self-healing layer includes polyurethane in a range of 60% to 80% by volume, epoxy vinyl ester in a range of 10% to 15% by volume, epoxy in a range of 10% to 15% by volume, polyurethane microcapsules filled with silane compound and in a range of 0.01% to 0.3% by volume, and a polysiloxane mixture in a range of 1% to 3% by volume. The polysiloxane mixture includes poly- dimethylsiloxane (PDMS) resin, hydroxy end-functionalized PDMS (HOPDMS), and poly-diethoxysiloxane (PDES). The polysiloxane mixture may be encapsulated or phase-separated. The self-healing Iayer may have a thickness in a range of about 15 pm to 100 μιπ.

[0033] At block 604 of the method 600, the substrate, with the self-healing Iayer, is disposed on the keyboard in a continuous manner to completely cover the keyboard. In an example, the substrate is applied on the keyboard to cover all keys of the keyboard thereby preventing any spilled liquid from entering the keyboard. [0034] FIG. 7 illustrates a method 700 of fabricating a self-healing keyboard of an electronic device, according to an example implementation of the present subject matter. At block 702 of the method 700, an adhesive layer may be applied on a substrate. The substrate may be made of a material selected from one of elastomers, polyester, and polycarbonate and may have a thickness in a range of about 25 pm to 900 pm. Further, the adhesive layer may be coated on the substrate through a spray coating technique, a spin-coating technique, an extrusion coating technique or a lamination technique. The adhesive layer may have a thickness in a range of about 1 pm to 30 pm, and includes urethane- acrylate, silicone, cyclic olefin copolymer, po!yacrylic, polycarbonate, or a combination thereof. In an example, a surface of the substrate may be cleaned before coating the adhesive layer.

[0035] At block 704, a self-healing iayer is coated on the adhesive layer, where the self-healing Iayer includes polyurethane in a range of 60% to 80% by volume, epoxy vinyl ester in a range of 10% to 15% by volume, epoxy in a range of 10% to 15% by volume, polyurethane microcapsules filled with silane compound and in a range of 0.01% to 0.3% by volume, and a poiysi!oxane mixture in a range of 1% to 3% by volume and included po!y-dimethylsiioxane (PDMS) resin, hydroxy end-functionaiized PDMS (HOPDMS), and po!y-diethoxysiloxane (PDES). The polysiloxane mixture may be encapsulated or phase-separated. The self-healing Iayer may have a thickness in a range of about 15 pm to 100 pm. in an example, the self-healing Iayer may be deposited on the adhesive iayer through spray coating.

[0036] At block 706 of the method 700, after coating the self-healing layer, the substrate may be heated at a temperature in a range of 60 °C to 150 °C for a time duration in a range of 3 minutes to 40 minutes for curing the self-healing iayer.

[0037] At block 708 of the method 700, the substrate is molded to conform to a shape of the keyboard on which the substrate is to be disposed. In an example, the substrate is molded using an injection molding technique, compression molding technique, or a blow molding technique. [0038] At bock 710 of the method 700, the substrate is disposed on the keyboard in a continuous manner so as to cover the keyboard. As the substrate is molded in accordance with the shape of the keyboard, the substrate covers all keys of the keyboard, thereby making the keyboard water-proof. In an example, the substrate may be attached to the keyboard using an adhesive or through thermal bonding.

[0039] Although implementations for keyboards, self-healing films, and methods of fabrication of keyboards have been described in language specific to methods and/or structural features, it is to be understood that the present subject matter is not limited to the specific methods or features described. Rather, the methods and specific features are disclosed and explained as example implementations for keyboards, self-healing films, and methods of fabrication of keyboards.