Patent Application
20120219702
Nanomaterials, such as carbon nanotubes (CNTs), demonstrate unique electrical properties and flexibility, making them useful in modern electronic devices. For instance, nanomaterials can be found in devices that require a flexible transparent conductor, such as displays and photovoltaic cells. These devices require that nanomaterials be patterned, as do other devices employing nanomaterials. Unfortunately, many of the properties making nanomaterials useful often make them expensive.
Electronic devices using nanomaterials (e.g., CNTs) exhibit benefits such as flexibility, transparency, and strength. These types of electronic devices can be circuits that include conductors, resistors, capacitors, inductors, and/or transistors, among other electronic components. However, as valuable as these devices are likely to be, the difficulty of patterning with nanomaterials, including CNTs, may add to manufacturing costs. Patterning electronic devices from nanomaterials may require precision processing techniques, such as photolithography and viscosity control, requiring multiple steps and/or added chemicals (e.g., developer, among others). The multiple steps and/or added chemicals involved in these processing techniques may increase the associated costs, may cause damage to the nanomaterials and/or a substrate upon which the nanomaterials are deposited, or both.
Embodiments of the present disclosure include patterning nanomaterial on a film. Such patterning can, in various embodiments, be performed by applying a uniform mixture of a solute in a solvent to a surface of the film to form a coating of soluble material on the surface of the film in a pre-defined pattern that defines coated parts of the film and uncoated parts of the film, depositing an aqueous dispersion, comprising a nanomaterial and a surfactant, on the defined coated and uncoated parts of the film, washing the film to remove the coating of soluble material and the nanomaterial from the defined coated parts of the film, but not removing the nanomaterial from the defined uncoated parts of the film, along with removing the surfactant from the defined coated and uncoated parts of the film. Doing so leaves a pattern of nanomaterial on the defined uncoated parts of the film.
In the following detailed description of the present disclosure, reference is made to the accompanying drawings that form a part hereof, and in which is shown by way of illustration how examples of the disclosure may be practiced. These examples are described in sufficient detail to enable those of ordinary skill in the art to practice the embodiments of this disclosure. It is to be understood that other examples may be utilized and that process, electrical, and/or structural changes may be made without departing from the scope of the present disclosure.
The figures herein follow a numbering convention in which the first digit or digits correspond to the drawing figure number and the remaining digits identify an element or component in the drawing. Similar elements or components between different figures may be identified by the use of similar digits. For example 104 may reference element “04” in
Patterning nanomaterial includes applying a uniform mixture of a solute in a solvent to a surface of the film to form a coating of soluble material on the surface of the film in a pre-defined pattern that defines coated parts of the film and uncoated parts of the film, as shown in block 102 of
Solute and solvent, as used herein, can be referred to in their combined state or individually. For example, polyvinyl alcohol (a solute) can be dissolved in propan-2-ol (a solvent). The solution formed thereby may be referred to industrially as Universal Protective Coating (UPC). In various embodiments, UPC can be used to form a coating of soluble material. Solute and solvent, as used herein, can also refer to combinations of more than one solute and/or more than one solvent. For example, water soluble ink can be used in forming a coating of soluble material as used herein. In some water soluble inks, water is the solvent and various solutes may be dissolved therein (e.g., pigments and/or dyes).
Forming a coating of soluble material on the surface of the film in a pre-defined pattern can include applying the uniform mixture in the pre-defined pattern to a desired thickness. For example, the uniform mixture can be applied to a thickness in a range of from 1 micrometer to 15 micrometers.
Patterning on a film, as used herein, can refer to, for example, patterning with a coating on a surface of a polyester-based film. Examples of polyester-based films include, but are not limited to, films comprising a thermoplastic polymer resin such as polyethylene terephthalate (PET) and/or polyethylene naphthalate (PEN). The film, as used herein, can range from transparent to opaque and from rigid to highly flexible.
As shown in block 104 of
Depositing the aqueous dispersion, comprising nanomaterial (e.g., CNTs) and a surfactant, on the defined coated and uncoated parts of the film can include, for example, depositing the aqueous dispersion such that the CNTs and surfactant are deposited to a uniform thickness. Depositing the aqueous dispersion, comprising CNTs and a surfactant, on the defined coated and uncoated parts of the film can also include, for example, depositing the aqueous dispersion such that the CNTs and surfactant are deposited to a desired thickness that is non-uniform. For example, the aqueous dispersion can be deposited to a thickness in a range of from 2.5 to 150 nanometers. Depositing the aqueous dispersion to a desired thickness can include, for example, aerosol spraying the aqueous dispersion to the desired uniform or non-uniform thickness.
Depositing the aqueous dispersion, comprising nanomaterial and a surfactant, on the defined coated and uncoated parts of the film can include heating the film to evaporate the water contained in the aqueous dispersion. Applying a uniform mixture of a solute in a solvent to a surface of the film to form a coating of a soluble material on the surface of the film in a pre-defined pattern, as described above, can include heating the film to evaporate the solvent. Heating, as used herein, can refer to conduction, convection, radiation, and combinations thereof.
Heating the film to evaporate the water contained in the aqueous dispersion and/or heating the film to evaporate the solvent from the coating of soluble material can include heating for a pre-determined time period to allow the solvent and/or water to fully evaporate from the film. The time required for evaporation can depend, for example, on the surfactant(s) applied, the proportion(s) of surfactants(s) to water and/or nanomaterial, the surface area of the film, and the thickness of the aqueous dispersion deposited, the solvent(s) applied, the solute(s) applied, the proportion(s) of solute(s) to solvent(s), the surface area of the film, the surface area of the film to which the solute(s) and solvent(s) were applied, and the thickness of the coating of soluble material, among other considerations. In various embodiments, the film can be heated to a temperature in a range of from 30 to 100 degrees Celsius to evaporate the solvent from the coating of soluble material before depositing the aqueous dispersion, as described above.
Patterning nanomaterial can include washing the film to remove the coating of soluble material and the nanomaterial from the defined coated parts of the film, but not removing the nanomaterial from the defined uncoated parts of the film, along with removing the surfactant from the defined coated and uncoated parts of the film, as shown in block 106 of
Washing the film can include removal of the soluble material (e.g., the solute), the surfactant, and nanomaterial from the coated parts of the film. Washing the film can also include allowing the film to air dry (e.g., by exposure to ambient or higher temperature and/or to air flow). For example, the film is washed with de-ionized water that dissolves the water-soluble surfactant and water-soluble solute. CNTs dispersed upon the defined solute-coated parts of the film are washed off the film when the solute upon which they were deposited dissolves. The film with the patterned CNTs can then be dried (e.g., air dried).
As shown in block 108 of
Example method 100, illustrated in
The film is heated to evaporate the solvent, as shown in block 244. As shown in block 246, an aqueous dispersion, comprising CNTs and a surfactant, is deposited on the defined coated and uncoated parts of the film.
Forming an electronic device can include washing the film to remove the soluble coating and the CNTs from the defined coated parts of the film, but not removing the nanomaterial from the defined uncoated parts of the film, along with removing the surfactant from the defined coated and uncoated parts of the film, as shown in block 248 of
As shown in block 250, a pattern of CNTs is left on the defined uncoated parts of the film that comprises at least one electronic device. The electronic device that is left on the film can be, for example, an electronic circuit that includes a number of conductors, resistors, capacitors, inductors, and/or transistors, among other components.
Example method 240 illustrated in
A spray apparatus 364 deposits an aerosol dispersion 368 of CNTs and a surfactant on the defined coated parts 380 and defined uncoated parts 372 of the film 360. As previously described, spray apparatus 364 can deposit the aerosol dispersion 368 on the defined coated parts 380 and defined uncoated parts 372 of the film 360 such that the CNTs and surfactant are deposited to a desired thickness that is uniform or non-uniform across the surface of the film 360. For example, spray apparatus 364 can deposit the aerosol dispersion 368 such that the CNTs and surfactant are deposited to a thickness in a range of from 2.5 to 150 nanometers.
Referring to
Referring to
The example system illustrated in
In conclusion, while the present disclosure has been particularly shown and described with reference to various embodiments, those skilled in the art will understand that many variations may be made herein without departing from the spirit and scope of the disclosure as defined in the following claims. This disclosure should be understood to include the novel and non-obvious combinations of elements described herein, and claims may be presented in this or a later application to any novel and non-obvious combination of these elements. The foregoing embodiments are illustrative, and no single feature or element is essential to all possible combinations that may be claimed in this or a later application. Whereas the claims recite “a” or “a first” element or the equivalent thereof, such claims should be understood to include incorporation of one or more such elements, neither requiring nor excluding two or more such elements.
