Cation gettering in liquid crystal NCAP and PDLC films.

Abstract

An electro-optic modulator is disclosed. The electro-optic modulator includes a modulator material film layer. The modulator material film layer includes a polymer matrix. Liquid crystals and getter molecules are dispersed within the polymer matrix. The liquid crystals are configured to modulate light transmittance through the electro-optic modulator. The getter molecules capture or coordinate cationic impurities present within the polymer matrix. Removal of the cationic impurities improves device switching at low modulated frequencies and also reduces the device's switching voltage. Three classes of getter molecules have been demonstrated to work: inorganic ion traps (ammonium dihydrogen phosphate), organic cation traps (EDTA), and organic ion extractors (nicotinic acid). The amount of getter molecules may be 0.01 to 1.0 weight percent of the polymer matrix.

Description

[Technical Field]

[0001] FIELD OF THE INVENTION The present invention relates generally to electro-optics, and more particularly to polymer dispersed liquid crystal materials for use in electro-optical applications. [Background technology]

[0002] Electro-optic modulators, which use liquid crystals, particularly NCAP or PDLC films, for modulation, are used to test thin-film transistor continuity and flat-panel display (FPD) interconnects during manufacturing. The presence of metal cations in the modulator's sensing layer, resulting from variations in incoming raw chemicals or formulation limitations, can adversely affect the modulator's performance by affecting its dielectric properties. In particular, metal cations can migrate within the electro-optic modulator in response to an electric field. The mobility of the cations can lead to electrostatic shielding of the electro-optic modulator's liquid crystal. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] U.S. Patent No. 6,151,153 [Patent Document 2] U.S. Patent No. 6,211,991 [Patent Document 3] U.S. Patent No. 6,866,887 [Patent Document 4] U.S. Patent No. 7,099,067 [Patent Document 5] U.S. Patent No. 7,817,333 [Patent Document 6] U.S. Patent No. 8,801,964 Summary of the Invention [Problem to be solved by the invention]

[0004] Therefore, it would be advantageous to provide devices, systems, and methods that address the above-mentioned shortcomings. [Means for solving the problem]

[0005] In accordance with one or more exemplary embodiments of the present disclosure, an electro-optic modulator is disclosed. In one exemplary embodiment, the electro-optic modulator includes a polymer matrix. In another exemplary embodiment, the electro-optic modulator includes liquid crystal molecules dispersed within the polymer matrix. In another exemplary embodiment, the electro-optic modulator includes getter molecules dispersed within the polymer matrix. In another exemplary embodiment, the getter molecules and the polymer matrix are each soluble in a solvent. In another exemplary embodiment, the getter molecules are insoluble in the liquid crystal molecules. In another exemplary embodiment, each of the getter molecules includes a cation and an anion configured to getter one or more cationic impurities from the polymer matrix.

[0006] An imaging system is disclosed in accordance with one or more embodiments of the present disclosure. In one exemplary embodiment, the imaging system includes an illumination source configured to generate illumination. In another exemplary embodiment, the imaging system includes a support for the sample. In another exemplary embodiment, the imaging system includes an electro-optic modulator disposed in a path of illumination from the illumination source and separated from the sample by an air gap. In another exemplary embodiment, the electro-optic modulator includes a polymer matrix. In another exemplary embodiment, the electro-optic modulator includes liquid crystal molecules dispersed within the polymer matrix. In another exemplary embodiment, the electro-optic modulator includes getter molecules dispersed within the polymer matrix. In another exemplary embodiment, the getter molecules and the polymer matrix are each soluble in a solvent. In another exemplary embodiment, the getter molecules are insoluble in the liquid crystal molecules. In another exemplary embodiment, each of the getter molecules includes a cation and its counteranion configured to remove one or more cationic impurities from the polymer matrix. In another exemplary embodiment, the getter molecules may include a chelating interaction. In another exemplary embodiment, the imaging system includes a detector to generate an image of at least a portion of the sample.

[0007] In accordance with one or more embodiments of the present disclosure, a method of fabricating an electro-optic modulator is disclosed. In one exemplary embodiment, the method includes adding getter molecules to a solution including polymer molecules dissolved in a solvent. In another exemplary embodiment, the method includes adding liquid crystal to the solution. In another exemplary embodiment, the method includes emulsifying the liquid crystal in the solution to disperse the liquid crystal and form a mixture. In another exemplary embodiment, the method includes coating a substrate with the mixture to form a film. In another exemplary embodiment, the method includes drying the film. In another exemplary embodiment, the film includes a polymer matrix formed from polymer molecules. In another exemplary embodiment, the film includes liquid crystal molecules dispersed within the polymer matrix. In another exemplary embodiment, the film includes getter molecules dispersed within the polymer matrix. In another exemplary embodiment, the getter molecules are soluble in the solvent. In another exemplary embodiment, the getter molecules are insoluble in the liquid crystal molecules. In another exemplary embodiment, each of the getter molecules includes an anion configured to remove one or more cationic impurities from the polymer matrix.

[0008] A polymer composition is disclosed in accordance with one or more embodiments of the present disclosure. In one exemplary embodiment, the polymer composition includes a polymer matrix formed by crosslinking a plurality of molecules. In another exemplary embodiment, the polymer composition includes a getter molecule dispersed within the polymer matrix. In another exemplary embodiment, the getter molecule and the polymer matrix are each soluble in a solvent. In another exemplary embodiment, the solvent is water. In another exemplary embodiment, the getter molecule includes a cation and an anion configured to remove one or more cationic impurities disposed within the polymer matrix. [Brief explanation of the drawings]

[0009] Many advantages of the present disclosure may be better understood, by those skilled in the art, by reference to the following drawings.

[0010] [Figure 1A]1 is a cross-sectional view of an electro-optic modulator in accordance with one or more embodiments of the present disclosure. [Figure 1B] 1 is a graph of transmittance versus voltage for an electro-optic modulator with and without getter molecules of the present disclosure in accordance with one or more embodiments of the present disclosure. [Figure 2] FIG. 1 is a flow diagram of a method for fabricating an electro-optic modulator in accordance with one or more embodiments of the present disclosure. [Figure 3] FIG. 1 is a schematic diagram of an imaging system in accordance with one or more embodiments of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0011] The present disclosure has been particularly shown and described with respect to certain embodiments and particular features thereof. The embodiments described herein are to be construed as illustrative and not restrictive. It will be readily apparent to those skilled in the art that various changes and modifications in form and detail may be made therein without departing from the spirit and scope of the present disclosure. Reference will now be made in detail to the disclosed subject matter, which is illustrated in the accompanying drawings.

[0012] The polymer matrix of an electro-optic modulator based on a nematic curvilinearly aligned phase (NCAP) or polymer-dispersed liquid crystal (PDLC) film can contain cations or cationic impurities. Cationic impurities can be present in the polymer matrix depending on the polymer raw material or how the polymer matrix is ​​fabricated. For example, a polymer matrix can be formed by dissolving water-soluble polymer molecules in water to form an aqueous solution. The aqueous solution may be slightly alkaline (e.g., pH 7.5 to pH 9). The cation content of the aqueous solution can vary based on several factors, including, but not limited to, the incoming raw chemicals or formulation limitations used to fabricate the polymer matrix. The polymer matrix can contain any type of cation, including, but not limited to, metal cations. For example, metal cations can include sodium, potassium, magnesium, calcium, etc. Cations are electrically mobile within the polymer matrix. For example, potassium ions in a polymer matrix are electrically mobile and drift in response to an electric field. Due to their mobility, potassium cations can provide electromagnetic shielding to liquid crystals dispersed within the polymer matrix. Electromagnetic shielding can undesirably affect the switching characteristics of electro-optical modulators. In particular, the switching characteristics of electro-optical modulators may not be optimal under certain pulse regimes due to contamination with sodium or potassium cations. Thus, excessive ionic contamination of the polymer matrix of electro-optical modulators has been shown to degrade switching performance in terms of response to changes in turn-on voltage and frequency of the electric field. Various getter molecules can be used as a solution to mitigate the effects of ions.

[0013] Embodiments of the present disclosure are generally directed to electro-optic modulators including one or more getter molecules for capturing cationic impurities present in the polymer matrix of the electro-optic modulator. The getter molecules may remove metal cations present in the polymer matrix, such as, but not limited to, potassium cations. The getter molecules may also be highly soluble and / or reactive with the polymer matrix to remove the metal cations, particularly when the polymer matrix is ​​in an aqueous solution. The getter molecules may also be selected to minimize changes in the pH of the aqueous solution. The anions of the getter molecules may be present in the polymer matrix and can remove, capture, or otherwise recover migrating cationic impurities. It is further contemplated that the getter molecules may include one or more cations (e.g., ammonium) that passivate electron trap states for one or more dangling bonds or other gap states that conduct via hopping. Passivating the electron trap states may reduce electrostatic screening of one or more liquid crystal (LC) molecules dispersed within the polymer matrix, thereby reducing the threshold electric field and / or hysteresis effects required to switch the liquid crystal. A reduction in the threshold electric field can improve the switching performance of the liquid crystal and reduce the turn-on voltage required to align the liquid crystal. The getter molecules can also have low solubility in the liquid crystal. The electro-optic modulator can be a component of an imaging system, also known as an automated optical inspection (AOI) system, voltage imaging optical system (VIOS), array checker, etc. By reducing the turn-on voltage, optical inspection process improvements can be improved as well. Embodiments of the present disclosure are also directed to methods of forming an electro-optic modulator.

[0014] Electro-optic modulators are generally described in U.S. Pat. No. 6,151,153, entitled "MODULATOR TRANSFER PROCESS AND ASSEMBLY," issued Nov. 21, 2000; U.S. Pat. No. 6,211,991, entitled "MODULATOR MANUFACTURING PROCESS AND DEVICE," issued April 3, 2001; U.S. Pat. No. 6,866,887, entitled "METHOD FOR MANUFACTURING PDLC-BASED ELECTRO-OPTIC MODULATOR USING SPIN COATING," issued March 15, 2005; U.S. Pat. No. 7,099,067, entitled "SCRATCH AND MAR RESISTANT PDLC MODULATOR," issued August 29, 2006; and U.S. Pat. No. 7,099,067, entitled "MODULATOR WITH IMPROVED ELECTRO-OPTIC MODULATORS," issued October 19, 2010. No. 7,817,333, entitled "Encapsulated Polymer Network Liquid Crystal Material, Device, and Applications," issued on August 12, 2014, each of which is incorporated herein by reference in its entirety.

[0015] FIG. 1A illustrates a cross-sectional view of an electro-optic modulator 100 including an ion getter material added to the polymer matrix of the electro-optic modulator 100 in accordance with one or more embodiments of the present disclosure. The electro-optic modulator 100 may include one or more layers, such as, but not limited to, a modulator material layer 108. The modulator material layer 108 may include a polymer matrix, liquid crystal droplets, and getter molecules. The polymer matrix may include cations or other cationic impurities that increase the drive voltage required to switch the liquid crystal dispersed therein. Getter molecules may be dispersed within the polymer matrix to remove cations, thereby lowering the switching voltage. Getter molecules may include one or more properties, such as, but not limited to, the ability to disperse within the polymer matrix, solubility in water or a host solvent, insolubility in liquid crystal molecules, and / or the ability to remove (i.e., capture) cations. Several such getter molecules are contemplated and described herein.

[0016] In embodiments, the modulator material layer 108 may include one or more getter molecules. The getter molecules may include one or more anions to remove or otherwise chelate cationic impurities from the matrix. To remove cationic impurities, the getter molecules may generally include anions. For example, the getter molecules may include anions and cations that migrate in response to an electric field. The anions are then free to remove cationic impurities (e.g., potassium or other metal cations) from the polymer matrix. In this regard, the cationic impurities are immobilized and neutralized with respect to charge. For example, the anions of the getter molecules may include any one of phosphate ions, carboxylate ions, sulfate ions, carbonate ions, thiosulfate ions, sulfite ions, acetate ions, borate ions, etc. As another example, the cations may include any one of hydrogen ions, ammonium ions, hydronium ions, alkyl ions, etc. Therefore, the addition of getter molecules to the modulator material layer 108 of an electro-optic modulator may reduce the voltage required to switch the liquid crystal in the modulator material layer 108. The getter molecules may then improve the switching properties of polymers containing cationic impurities. The voltage drop is believed, but not intended to be limiting, to be due to the cations of the getter molecules deactivating one or more electron trap states.

[0017] In embodiments, the cation comprises an organic group. In embodiments, the organic group comprises a compound or group comprising two carbon atoms bonded to each other, wherein at least one carbon atom is bonded to at least one hydrogen and / or halogen. Furthermore, one carbon atom may be bonded to at least one nitrogen atom by a single or double bond. The organic group may include any suitable organic group, for example, but not limited to, n-butyl, n-propyl, or isopropyl. Isopropyl p-toluenesulfonate and n-butyl acetate are examples of cation-anion combinations that can remove metal cations.

[0018] In embodiments, the polymer matrix and the getter molecules are soluble in a common solvent. For example, the solvent may include water to form an aqueous solution, but this is not intended to be limiting. The getter molecules can be water-soluble by including polar molecules that are soluble in an aqueous solution (e.g., including polymer molecules and water) to ionize and form anions. The anions may include a negative charge to electrostatically bond with cations present in the polymer matrix. Furthermore, being water-soluble allows the getter molecules to be dispersed within the polymer matrix, for example, during emulsification of a liquid crystal. For example, an NCAP film can be formed from an aqueous solution.

[0019] In embodiments, the getter molecule may be compatible with the polymer molecules used to form the polymer matrix, such as, but not limited to, polyvinyl alcohol (PVA), polyurethane, or polyacrylate. The getter molecule may also be compatible with one or more additives, such as, but not limited to, surfactants, used to formulate the polymer matrix. In embodiments, the getter molecule does not substantially change the pH of the aqueous solution. In this regard, the polymer molecules dissolved in the aqueous solution may have a pH between pH 7.5 and pH 9. By not affecting the pH of the aqueous solution, crosslinking of the polymer molecules to form the polymer matrix may likewise be unaffected.

[0020] In embodiments, the getter molecules are insoluble in the liquid crystal material. By being insoluble in the liquid crystal material, the getter molecules may be prevented from interfering with the switching of the liquid crystal or may act as an interfacial agent. By not acting as an interfacial agent, the getter molecules may have minimal effect on the anchoring or frictional forces between the polymer matrix and the liquid crystal. Furthermore, the getter molecules are dispersed within the polymer matrix, not the liquid crystal. In some embodiments, the getter may improve the hardness of the polymer matrix. For example, an NCAP film may be harder when the getter is present within the film.

[0021] Some getter molecules may be contemplated to be configured to remove one or more cations from the polymer matrix. Getter molecules generally include some organic or inorganic compounds. Cation abstraction can occur through one or more classes of getter molecules, such as, but not limited to, inorganic salts with cation reactivity, organic compounds with cation abstraction capability, or organic compounds with cation extractability.

[0022] In embodiments, the getter molecule may include one or more organic or inorganic acids and / or salts thereof. The getter molecule may include a cation that can be substituted with an anion. The anion may then scavenge cationic impurities from the polymer matrix. The getter molecule may be selected based on its pKa value. The pKa is a measure of acidity and provides an estimate of the stability of the anion formed in aqueous solution. For example, the getter molecule may include any of the chemicals listed in Table 1 and may further include a cation selected from one of hydrogen, ammonium, hydronium, or an organic group.

[0023] [Table 1]

[0024] In some cases, the pKa value provides a basis for selecting a getter molecule. The getter molecule can be selected to have a pKa that is not too low, thus not significantly lowering the solution pH and thus not interfering with crosslinking. The getter molecule can also be selected to have a pKa that is not too high, thus not causing insufficient dissociation or otherwise providing sufficient gettering for impurities. The concentration can also be selected so as not to significantly change the pH, so that crosslinking of the polymer is not significantly hindered. For example, getter molecules may be selected to have a pKa between 0 and 3, such as nicotinic acid, ammonium dihydrogen phosphate, or ethylenediaminetetraacetic acid (EDTA), although this is not intended to be limiting. Solubility and chemical compatibility can also provide a basis for selecting a getter molecule to avoid phase separation or further aggregation of the polymer in solution. The range of ionization and the equilibrium constant (Ka) of ionization can also provide a basis for selecting a chemical cation. In this regard, buffer solutions can be created from compounds (or mixtures) based on ionic strength for pH control.

[0025] In embodiments, the getter molecule comprises a phosphate group. The phosphate group is selected from phosphate salts ([PO4]) taking into account the overall pH of the formulation to ensure proper cross-linking. 3- ), hydrogen phosphate ([HPO4] 2- ), dihydrogen phosphate ([H2PO4] 1- ) or phosphoric acid (H3PO4). Similarly, the getter molecule may be a phosphate ([PO4] 3- ), hydrogen phosphate ([HPO4] 2- ), dihydrogen phosphate ([H2PO4] 1- ) together with a cation such as, but not limited to, hydrogen, ammonium, or hydronium.

[0026] For example, the getter molecule may comprise ammonium dihydrogen phosphate, which may comprise a formulation based on: [ka]

[0027] Ammonium dihydrogen phosphate has been experimentally successful as a getter molecule. When ammonium dihydrogen phosphate is added to NCAP or PDLC films, the dihydrogen phosphate moiety can scavenge cationic impurities. Although ammonium is a cation, experimental studies have confirmed that ammonium improves switching characteristics rather than adversely affecting them. It is believed that the improvement in switching behavior may be due to ammonium passivating one or more dangling bonds or other gap states. For example, NCAP or PDLC films may contain one or more dangling bonds (e.g., with unsatisfied valences) or other gap states that can conduct via hopping. Dangling bonds can undesirably prevent conduction and charging. Therefore, ammonium may improve the conduction and charging capabilities of NCAP or PDLC films by passivating them, but this is not intended to be limiting.

[0028] It is further contemplated that the getter molecule may comprise a sulfonic acid or a sulfonate thereof. The sulfonic acid may comprise a formulation based on the following, where R is an organic group: [ka]

[0029] Sulfonic acids may be included in several chemicals, such as, but not limited to, polystyrene sulfonic acid or its polystyrene sulfonate salts. The polystyrene sulfonate salts may include formulations based on: [ka]

[0030] Amberlite resins may be based on such polystyrene sulfonic acid or its salts. Polystyrene sulfonates generally may contain one or more cations, such as, but not limited to, hydrogen, ammonium, or hydronium. For example, the getter molecule may include ammonium polystyrene sulfonate.

[0031] In embodiments, the getter molecule comprises a carboxylic acid group. A getter molecule comprising a carboxylic acid group may be soluble in water (e.g., an aqueous solution containing a polymer) and may remove cationic impurities from a polymer matrix. The carboxylic acid group may be an organic acid containing a carboxyl group attached to an R group. Carboxylate salts may also be used as getter molecules. The carboxylate salts may comprise a carboxylate group attached to the R group. The carboxylate group may comprise M, where M is selected from one of hydrogen, ammonium, or hydronium. The carboxylate salts may include formulations based on the following: [ka]

[0032] In embodiments, the getter molecule may comprise one or more organic compounds with cation abstraction capabilities. Chelators are a class of compounds that reactively remove metal ions. Chelators may contain anions that react with cationic impurities in the polymer matrix or coordinate to cations without an anion-bearing agent. For example, chelators may include, but are not limited to, ethylenediaminetetraacetic acid (EDTA) or its salts. EDTA may comprise a multidentate structure for ion abstraction. Such a multidentate structure may contain four carboxylic acid groups and / or carboxylate salt groups, each of which can serve as a cationic receptor site for abstracting or removing cationic impurities. Thus, one or more carboxylic acid groups and / or carboxylate salt groups may act as organic getters for potassium or other cationic impurities in the polymer matrix. Furthermore, EDTA may have suitable miscibility in water and sufficient purity. EDTA may include formulations based on the following: [ka]

[0033] In embodiments, the getter molecule may comprise one or more organic compounds with cation abstraction capability. Ionophores are a class of molecules used in pharmaceuticals for ion transport. Several such ionophores exist, including, but not limited to, valinomycin. Valinomycin may be used as a potassium ionophore. Valinomycin may include formulations based on: [ka]

[0034] The ionophore may also include nicotinic acid or its salt. It has been experimentally determined that nicotinic acid functions as a getter molecule for potassium ions in a polymer matrix. Nicotinic acid may contain a carboxylic acid group that can act as an organic ion extractor for potassium or other cationic impurities in the polymer matrix. Similarly, a salt of nicotinic acid may contain a carboxylic acid group. For example, nicotinic acid may include a formulation based on: [ka]

[0035] In an embodiment, a certain amount of getter molecules is added to the polymer matrix. The amount can be selected based on the content of cationic impurities present in the aqueous solution. For example, 0.01 to 1.0 percent of the polymer matrix may be added to the aqueous solution. The getter molecules may be added during the initial stage of electro-optic modulator formulation, for example, but not limited to, before adding the liquid crystal to the aqueous solution.

[0036] Thus, the modulator material layer 108 may include one or more polymer matrices, liquid crystals, and one or more getter molecules. In embodiments, the electro-optic modulator 100 may include one or more films, layers, or coatings in addition to the modulator material layer 108. For example, the electro-optic modulator 100 may include one or more hard coating layers 102, plastic films 104, dielectric mirror films 106, the modulator material layer 108, transparent conductive layers 110, plastic films 112, optical adhesives 114, glass substrates 116, and / or anti-reflective coatings 118. Thus, the electro-optic modulator 100 may include one or more film layers that allow light to pass through. The light transmittance through the modulator material layer 108 may also vary depending on the magnitude of the electric field experienced by the liquid crystals in the modulator material layer 108. It is further contemplated that the electro-optic modulator is not limited to the films, layers, or coatings described above.

[0037] The modulator material layer 108 (also referred to as a sensor layer, liquid crystal layer, polymer matrix layer, etc.) can be applied onto the glass substrate 116 by several methods, including, but not limited to, direct coating or lamination. An embodiment made by a lamination process involves first coating a plastic film 112 (e.g., polyethylene terephthalate (PET), also known as Mylar) having a transparent conductive layer 110 with the modulator material layer. The transparent conductive layer 110 can generally comprise any material that is optically transparent and conductive to act as an electrode, including, but not limited to, indium tin oxide (ITO). The modulator material layer 108 can comprise an NCAP blend or a PDLC blend. The transparent conductive layer 110 and modulator material layer 108, as well as the plastic film 112, can be laminated onto the glass substrate 116 with an optical adhesive 114. The dielectric mirror film 106 (or pellicle) can be formed on the plastic film 104 and then applied to the modulator material layer 108 of the assembly stack. The dielectric mirror coating can be deposited by physical vapor deposition or a similar process. In an embodiment, a vacuum assisted attachment process is used. The dielectric mirror film 106 capacitively couples to the sample to induce a local voltage. The local voltage then aligns the liquid crystals in the modulator material layer 108. An anti-reflective coating 118 can be applied to the bottom surface of the glass substrate 116. Similarly, the hard coating layer 102 can be cured to the plastic film 104. The hard coating layer 102 can include a main hard coating and a thinner slip agent layer.

[0038] Referring to FIG. 1B, a graph 101 of transmittance versus voltage is shown in accordance with one or more embodiments of the present disclosure. Graph 101 shows the normalized transmittance of electro-optic modulator 100 without and with getter molecules as a function of voltage. Curve 103 represents a control VT curve obtained from an electro-optic modulator containing no getter molecules in the NCAP film. Curve 105 represents a VT curve obtained from an electro-optic modulator containing a 0.2% getter molecule concentration in the NCAP film. As shown in graph 101, the presence of getter molecules in the electro-optic modulator allows for sufficient transmittance to be achieved at a lower voltage than would be required without gettering.

[0039] 2 is a flow diagram describing the steps performed in a method 200 of fabricating an electro-optic modulator in accordance with one or more embodiments of the present disclosure. The embodiments and enabling techniques described herein above in the context of electro-optic modulator 100 should be construed as extending to method 200. However, it is further noted that method 200 is not limited to the structure of electro-optic modulator 100.

[0040] In step 210, getter molecules are added to a solution of polymer molecules dissolved in a solvent. For example, the polymer dissolved in the solvent may be polyvinyl alcohol (PVA) or urethane dissolved in water to form an aqueous solution. It is further contemplated that the solvent may be another solvent used to formulate the PDLC film, such as, but not limited to, a solvent for a latex polymer, a monomer, or the like. The solution may be a homogeneous solution. In embodiments, the getter molecule may be any getter molecule previously described herein. For example, getter molecules may include several compounds, such as, but not limited to, nicotinic acid or another nicotinic acid salt (e.g., ammonium nicotinate), ethylenediaminetetraacetic acid (EDTA) or another ethylenediaminetetraacetic acid salt (e.g., n-ammonium ethylenediaminetetraacetate), iminodisuccinic acid, polyaspartic acid, valinomycin, dihydrogen phosphate salt (e.g., ammonium dihydrogen phosphate), and / or polystyrene sulfonic acid or another polystyrene sulfonate salt (e.g., ammonium polystyrene sulfonate). The getter molecules may also be insoluble in the liquid crystal. The getter molecules may be added based on the relative weight of the getter molecules and the polymer molecules. For example, the getter molecules may comprise 0.01 to 1.0 weight percent of the polymer molecules.

[0041] In step 220, the liquid crystal is added to the aqueous solution to form a mixture. The combination of the liquid crystal and the aqueous solution may be a two-phase mixture. In this regard, the liquid crystal may be relatively immiscible with the aqueous solution. The liquid crystal may include any liquid crystal composite material, such as, but not limited to, an NCAP material (e.g., a water-soluble polymer-based NCAP material or a latex polymer-based NCAP) or a PDLC material. The liquid crystal may form droplets containing some molecules of the liquid crystal material.

[0042] In step 230, the liquid crystal material is emulsified within the polymer material. Emulsifying the liquid crystal material can improve the electrical performance of the liquid crystal material. The liquid crystal can form smaller droplets (on the order of 1-10 microns in size) that are dispersed within the polymer material. The liquid crystal molecules can be randomly oriented within the droplets when no electric field is applied. The liquid crystal / polymer material can be emulsified using any method, including, but not limited to, mechanical force using a high-speed blade.

[0043] In step 240, the emulsified mixture is applied to a substrate. The emulsified mixture may be applied as a thin film (on the order of 10 microns thick). For example, the thin film may be applied by a spin coating process or the like.

[0044] In step 250, the film is dried. Drying the film evaporates the water in the thin film. After the water evaporates, the liquid crystal remains dispersed within the polymer matrix. The liquid crystal molecules may anchor to the polymer matrix. The degree of anchoring depends on the chemical properties of the liquid crystal molecules and the polymer. When an electric field is applied across the liquid crystal material, the liquid crystal molecules and / or droplets may at least partially align along the direction of the electric field. For such alignment to occur, the liquid crystal molecules and / or droplets overcome friction with the polymer at the anchoring and / or attachment sites.

[0045] In some embodiments, getter molecules may also be dispersed within the polymer matrix after water evaporation. The getter molecules may also remove cationic contaminants present within the polymer matrix. Removing the cationic contaminants may reduce electromagnetic shielding of the liquid crystal molecules. Therefore, the switching voltage of the film may be improved compared to electro-optical modulators that do not contain getter molecules. After the film is cured, the getter molecules present in the polymer matrix can easily capture nearby floating cations, effectively suppressing their migration and neutralizing their charge. The ions are then unable to migrate under an AC electric field during modulator operation, an effect that becomes more pronounced as the frequency decreases, resulting in the inability to electrostatically shield the liquid crystal from switching.

[0046] It is further contemplated that each embodiment of the above method may include any other step of any other method described herein. For example, it is contemplated that getter molecules may be added to the aqueous solution before, simultaneously with, or after adding the liquid crystal to the aqueous solution.

[0047] FIG. 3 is a conceptual diagram illustrating an imaging system 300 in accordance with one or more embodiments of the present disclosure. In this disclosure, the term “imaging system” is interchangeable with the term “imaging tool.” The imaging system 300 may generally include any type of suitable imaging tool, such as, but not limited to, voltage imaging. Voltage imaging can be used to detect and measure defects in flat-panel thin-film transistor (TFT) arrays. The performance of the TFT array is simulated as if assembled into TFT cells, and the characteristics of the TFT array are then measured by indirectly measuring the actual voltage distribution on the panel using an electro-optic modulator (e.g., electro-optic modulator 100), or so-called voltage imaging. Voltage imaging can be performed by the imaging system 300. The imaging system 300 may include one or more components for checking such TFT arrays or other samples.

[0048] The electro-optic modulator 100 may be advantageous for some imaging tasks, such as modulating the light source of an imaging system 300 to help detect one or more defects in a sample 311, such as, but not limited to, a thin film transistor (TFT) array, a liquid crystal display (LCD) panel, or the like. The TFT array may be formed on a substrate, such as a thin, transparent plate of glass. The TFT array may include one or more printed layers. The printed layers may be formed on the substrate by several processes, such as, but not limited to, one or more material deposition steps, one or more lithography steps, one or more etching steps, etc. Fabrication may be performed in stages, where a material (e.g., indium tin oxide (ITO)) is deposited on a previous layer or on a glass substrate according to a process pattern. During fabrication, the printed layers are manufactured within selected tolerances to accurately build the final device. The printed layers may exhibit defects outside the selected tolerances. The characteristics of the TFT array can be measured by the imaging system 300 to detect defects.

[0049] In an embodiment, the imaging system 300 includes an illumination source 306 for generating illumination 308. The illumination 308 may include light of one or more selected wavelengths, including, but not limited to, vacuum ultraviolet (VUV), deep ultraviolet (DUV), ultraviolet (UV), visible light, or infrared (IR). The illumination source 306 may further generate illumination 308 including any range of selected wavelengths. In an embodiment, the illumination source 306 may include a spectrally tunable illumination source for generating illumination 308 having a tunable spectrum.

[0050] In an embodiment, illumination source 306 directs illumination 308 to sample 311 via illumination path 309. Illumination path 309 may include one or more lenses 312 or additional illumination optical components 314 suitable for modifying and / or adjusting the illumination 308. For example, one or more illumination optical components 314 may include, but are not limited to, one or more polarizers, one or more filters, one or more splitters, one or more diffusers, one or more homogenizers, one or more apodizers, one or more shapers, one or more shutters (e.g., mechanical shutters, electro-optical shutters, acousto-optical shutters, etc.), one or more aperture stops, and / or one or more field stops.

[0051] In an embodiment, the imaging system 300 includes an electro-optic modulator 100. The electro-optic modulator 100 can modulate one or more characteristics of the illumination 308. During operation, light is transmitted through a portion of the electro-optic modulator 100, and defects can be detected by observing changes in the reflected or transmitted light. The electro-optic modulator 100 may be positioned a selected number of microns (e.g., 5-75 microns) above the surface of a sample 311 (e.g., a TFT array), and a voltage bias is applied across transparent electrodes in a layer of indium tin oxide (hereinafter, "ITO") on the surface of the electro-optic modulator 100. The electro-optic modulator 100 then capacitively couples to the sample 311, such that an electric field associated with the sample 311 is sensed by one or more layers (e.g., layers containing liquid crystals) of the electro-optic modulator 100. The intensity of incident light transmitted through the liquid crystals of the electro-optic modulator changes (i.e., modulates) based on the strength of the electric field felt by the liquid crystals. For example, in areas where typical pixels are located, a local voltage potential is applied (e.g., capacitive coupling between the sample 311 and the electro-optic modulator 100), causing one or more films of the electro-optic modulator 100 to become locally translucent. In the locally translucent areas, light from the light source 306 can pass through the electro-optic modulator 100, be reflected from the sample 311, and pass through the collection path 322 (e.g., for capture by the detector 304). As another example, in areas where no voltage potential is applied (e.g., no capacitive coupling), one or more films of the electro-optic modulator 100 remain locally opaque. When the electro-optic modulator 100 is locally opaque, light from the light source 306 is scattered or otherwise prevented from passing to the sample 311. Thus, a transmission-voltage (TV) curve can be determined by applying a voltage. The intrinsic switching voltage of the electro-optic modulator 100 may correspond to the voltage across the electro-optic modulator 100 at which light transmission through the electro-optic modulator 100 has a maximum sensitivity to changes in voltage. For example, the switching voltage may correspond to an electric field strength at which a given percentage of the liquid crystal molecules substantially align with the electric field to allow light transmission.

[0052] In an embodiment, the sample 311 includes a thin film transistor (TFT) array. For example, the sample 311 may include pixel elements disposed between inactive areas. The sample stage 318 may include any device suitable for positioning the sample 311 within the imaging system 300.

[0053] In an embodiment, detector 304 is configured to capture radiation emanating from sample 311 (e.g., sample light 320) through collection path 322. For example, collection path 322 may, but need not, include electro-optic modulator 100, a collection lens (e.g., an objective lens), or one or more additional collection path lenses 324. In this regard, detector 304 may receive radiation reflected or scattered from sample 311 (e.g., via specular reflection, diffuse reflection, etc.) or radiation generated by sample 311 (e.g., luminescence associated with absorption of illumination 308, etc.).

[0054] System 300 may include, but is not limited to, a controller 303. Controller 303 may include one or more processors and memory, and may include or be coupled to a user interface 310.

[0055] The collection path 322 may further include any number of collection optical components 326 to direct and / or modify the illumination collected by the electro-optic modulator 100, including, but not limited to, one or more collection path lenses 324, one or more filters, one or more polarizers, or one or more blocks. Additionally, the collection path 322 may include a field stop to control the spatial extent of the sample imaged onto the detector 304, or an aperture stop to control the angular extent of illumination from the sample used to generate the image on the detector 304. In another embodiment, the collection path 322 includes an aperture stop located at a plane conjugate to the back focal plane of the optical elements to provide telecentric imaging of the sample. In an embodiment, the imaging system 300 includes a beam splitter 328 oriented to enable the electro-optic modulator 100 to simultaneously direct illumination 308 to the sample 311 and collect radiation emanating from the sample 311.

[0056] The detector 304 may include any type of optical detector suitable for measuring illumination received from the sample 311. For example, the detector 304 may include, but is not limited to, a CCD detector, a TDI detector, a photomultiplier tube (PMT), an avalanche photodiode (APD), a complementary metal-oxide semiconductor (CMOS) sensor, etc. In another embodiment, the detector 304 may include a spectroscopic detector suitable for identifying wavelengths of light emanating from the sample 311.

[0057] In an embodiment, a controller 303 is communicatively coupled to the detector 304. The controller 303 may include one or more processors configured to perform any of a variety of process steps. In an embodiment, the controller 303 is configured to generate and provide one or more control signals configured to make one or more adjustments to one or more process tools based on the image signal 313 from the detector 304.

[0058] The one or more processors of controller 303 may include any processor or processing element known in the art. In this disclosure, the term “processor” or “processing element” may be broadly defined to encompass any device having one or more processing or logic elements (e.g., one or more microprocessor devices, one or more application-specific integrated circuit (ASIC) devices, one or more field-programmable gate arrays (FPGAs), or one or more digital signal processors (DSPs)). In this sense, one or more processors may include any device configured to execute algorithms and / or instructions (e.g., program instructions stored in memory). In one embodiment, the one or more processors may be embodied as a desktop computer, mainframe computer system, workstation, image computer, parallel processor, network computer, or any other computer system configured to execute programs configured to operate or operate in conjunction with imaging system 300 as described throughout this disclosure. Additionally, different subsystems of system 300 may include processors or logic elements suitable for performing at least some of the processes described in this disclosure. Therefore, the above description should not be construed as limiting the embodiments of the present disclosure, but merely as illustrative. Furthermore, the processes described throughout this disclosure may be performed by a single controller or multiple controllers. In addition, controller 303 may include one or more controllers housed within a common housing or multiple housings. In this manner, any controller or combination of controllers may be packaged separately as a module suitable for integration into imaging system 300. Furthermore, controller 303 may analyze data received from detector 304 and provide the data to additional components within or external to imaging system 300.

[0059] The memory medium may include any storage medium known in the art suitable for storing program instructions executable by the associated one or more processors. For example, the memory medium may include a non-transitory memory medium. As another example, the memory medium may include, but is not limited to, read-only memory (ROM), random access memory (RAM), magnetic or optical memory devices (e.g., disks), magnetic tape, solid-state drives, etc. Furthermore, it should be noted that the memory medium may be housed in a common controller housing along with one or more processors. In one embodiment, the memory medium may be located remotely relative to the physical location of one or more processors and controllers. For example, one or more processors of the controller 303 may access a remote memory (e.g., a server) accessible via a network (e.g., the Internet, an intranet, etc.).

[0060] In embodiments, user interface 310 is communicatively coupled to controller 303. In embodiments, user interface 310 may include, but is not limited to, one or more desktops, laptops, tablets, etc. In embodiments, user interface 310 includes a display used to display system 300 data to a user. The display of user interface 310 may include any display known in the art. For example, the display may include, but is not limited to, a liquid crystal display (LCD), an organic light emitting diode (OLED)-based display, or a CRT display. Those skilled in the art will recognize that any display device that can be integrated with user interface 310 is suitable for implementation in the present disclosure. In embodiments, a user may input selections and / or commands in response to data displayed to the user via a user input device of user interface 310.

[0061] Generally, referring back to FIGS. 1A-3, getter molecules have been described as being added to an electro-optic modulator in an imaging system, but this is not intended to limit the present disclosure. It is further contemplated that getter molecules may be added to some water-based polymers. Adding getter molecules to water-based polymers can improve the dielectric properties of the water-based polymer. For example, leakage current or dielectric loss of water-based polymers may be a concern. Adding getter molecules can improve the dielectric properties, such as capacitance, of water-based polymers. Therefore, getter molecules can address issues related to free cations, such as capacitance or film fouling. Such water-based polymers may have several beneficial applications, such as smart window technology, sensors, or other nematic curvilinearly aligned liquid crystal (NCAP) films. In solvent-based systems, polymer-dispersed liquid crystal (PDLC) films and polymer-stabilized liquid crystal (PSLC) films may similarly be improved.

[0062] Gettering may be beneficial for some polymer compositions. The polymer composition may include a polymer matrix formed by crosslinking multiple polymer molecules. The polymer composition may also include getter molecules dispersed within the polymer matrix. The getter molecules and the polymer matrix may each be soluble in a solvent, such as, but not limited to, water. Each of the getter molecules may include a cation and an anion. The anion may be configured to remove one or more cationic impurities disposed within the polymer matrix. In embodiments, the getter molecules comprise 0.01 to 1.0 weight percent of the polymer matrix, although this is not intended to be limiting. In embodiments, the anion includes at least one of phosphate ions, carboxylate ions, sulfate ions, carbonate ions, thiosulfate ions, sulfite ions, acetate ions, or borate ions. In embodiments, the cation is hydrogen, ammonium, hydronium, or one of an organic group. In embodiments, the plurality of getter molecules is at least one of nicotinic acid, nicotinic acid salts, ethylenediaminetetraacetic acid (EDTA), ammonium dihydrogen phosphate, polystyrene sulfonic acid, polystyrene sulfonate, or valinomycin. The getter molecules may have pKa values ​​between 0 and 3, but this is not intended to be limiting.

[0063] The modulator material layer may include a polymer matrix and a liquid crystal dispersed within the polymer matrix. The intrinsic switching voltage of the liquid crystal may correspond to the voltage across the modulator material layer at which light transmission through the electro-optic modulator is most sensitive to changes in voltage. Sensitivity may be improved by lowering the intrinsic switching voltage of the liquid crystal material. The operating voltage and sensitivity of the liquid crystal material may be related to one or more factors, including, but not limited to, the properties of the liquid crystal, the properties of the polymer matrix, the liquid crystal droplet size distribution in the polymer matrix, and / or the interfacial properties between the polymer matrix and the liquid crystal.

[0064] The modulator material layer may comprise one or more classes of materials. Liquid crystal / polymer composite materials can generally be divided into polymer dispersed liquid crystal (PDLC) and nematic curvilinear aligned phase liquid crystal (NCAP) material classes. PDLC and NCAP materials may each generally comprise liquid crystal droplets dispersed within a polymer matrix.

[0065] PDLC materials or films can be manufactured by several methods. For example, PDLC materials can be manufactured by solvent-induced phase separation (SIPS). The SIPS process can involve dissolving a liquid crystal (LC) and a polymer in a common solvent and then evaporating the solvent to form LC droplets. The getter molecule can also be selected to be soluble in the common solvent. In some cases, the solvent is water, but this is not intended to be limiting. Crosslinkable polymers are often used to further improve the mechanical properties (such as toughness) of the final PDLC film. As another example, PDLC materials can be manufactured by polymerization-induced phase separation (PIPS). The PIPS process can involve mixing LC and a prepolymer (and / or monomer) and applying radiation (e.g., ultraviolet light) to the mixture. The PIPS process can also involve mixing a catalyst, LC, and prepolymer, followed by heating to form a PDLC film. As another example, PDLC materials can be manufactured by thermally induced phase separation (TIPS). The TIPS process can involve heating a mixture of polymer and LC until the mixture is homogeneous. The LC then phase separates from the polymer during the cooling process.

[0066] NCAP materials or films may be suitable for the fabrication of very large-area light valves and displays. NCAP materials or films are generally water-based and can be further divided into several subclasses. For example, subclasses of NCAP materials include water-soluble polymers such as polyvinyl alcohol (PVA) or urethane. Water-soluble polymers may be moisture-sensitive due to their hydrophilic nature. As another example, a subclass of NCAP materials includes latex-based materials. Latex-based materials include water-insoluble polymers. Latex particles may be dispersed in water along with liquid crystals. These latex particles may "fuse" into an irreversible continuous polymer phase when the water is removed. Some applications using this latex-based NCAP have long-term electro-optical stability.

[0067] The liquid crystal material may include any liquid crystal material. For example, the liquid crystal may include, but is not limited to, one or more of nematic liquid crystals, ferroelectric liquid crystals, blue phase liquid crystals, a mixture of liquid crystals and dichroic dyes, cholesteric liquid crystals, etc. In a mixture of dichroic dyes and liquid crystals, the dichroic dyes can absorb light in the off state and transmit light in the on state, which results in improved light transmission voltage sensitivity corresponding to the slope of the S-curve when using higher light intensities. The liquid crystal material may be substantially hydrophobic, and droplets of the liquid crystal material may be formed in an emulsion, with a prepolymer and a photoinitiator substantially dissolved in the liquid crystal droplets. The prepolymer and photoinitiator may be substantially hydrophobic, and the liquid crystal droplets of the emulsion contain a majority of the mixture of photoinitiator and prepolymer.

[0068] The polymer matrix material may include any polymeric material. For example, the polymer matrix material may include, but is not limited to, one or more water-based polymers, such as polyvinyl alcohol (PVA) or urethane, or a water-based latex, such as Neorez R-967 (manufactured by NeoResins, a division of DSM). The amount of polymer matrix material may correspond to the strength and rigidity of the sensor material. The weight ratio of the liquid crystal material to the polymer matrix material may be, for example, within a range of about 50 / 50 to about 80 / 20. Increasing the amount of polymer matrix material may increase the strength and operating voltage of the sensor material. The polymer matrix may be dissolved in water to form an aqueous mixture. During the formation of the modulator material layer 108, one or more surfactants (e.g., wetting agents) may be added to the aqueous mixture. The surfactant may improve the spreading ability of the modulator material layer 108 by reducing surface tension.

[0069] As used throughout this disclosure, the term "specimen" generally refers to a substrate formed of a semiconductor or non-semiconductor material (e.g., thin-film glass, etc.). For example, the semiconductor or non-semiconductor material may include, but is not limited to, single-crystal silicon, gallium arsenide, indium phosphide, or glass material. The specimen may include one or more layers. For example, such layers may include, but are not limited to, resist (including photoresist), dielectric materials, conductive materials, and semiconducting materials. Many different types of such layers are known in the art, and the term specimen, as used herein, is intended to encompass specimens upon which any type of such layer may be formed. The one or more layers formed on the specimen may be patterned or unpatterned. For example, a specimen may include multiple dies, each with repeating patterned features. The formation and processing of such layers of material may ultimately result in a completed device. Many different types of devices can be formed on a specimen, and the term specimen, as used herein, is intended to encompass specimens upon which any type of device known in the art may be fabricated. Additionally, for purposes of this disclosure, the terms specimen and wafer should be considered interchangeable. Additionally, for purposes of this disclosure, the terms patterning device, mask, and reticle should be considered interchangeable.

[0070] It is further contemplated that each embodiment of the above method may include any other step(s) of any other method(s) described herein. Moreover, each embodiment of the above method may be performed by any of the systems described herein.

[0071] Those skilled in the art will recognize that the component operations, devices, objects, and accompanying discussions described herein are used as examples for conceptual clarity, and that various configuration variations are contemplated. Consequently, the specific examples described herein and the accompanying discussion are intended to be representative of their more general classes. In general, the use of any specific example is intended to represent that class, and the failure to encompass a particular component, operation, device, and object should not be construed as limiting.

[0072] As used herein, directional terms such as "top," "bottom," "above," "below," "upper," "above," "lower," "below," and "below" are intended to provide relative positions for purposes of description and are not intended to indicate an absolute frame of reference. Various modifications to the described embodiments will be apparent to those skilled in the art, and the general principles defined herein may be applied to other embodiments.

[0073] With respect to the use of virtually any plural and / or singular term herein, those skilled in the art can convert from plural to singular and / or from singular to plural as appropriate to the context and / or application. The various singular / plural permutations are not expressly set forth herein for the sake of clarity.

[0074] The subject matter described herein may illustrate different components contained within or connected to other components. It should be understood that the architectures depicted are merely exemplary, and that in fact many other architectures that achieve the same functionality may be implemented. In a conceptual sense, any configuration of components to achieve the same functionality is effectively “associated” such that the desired functionality is achieved. Thus, any two components herein that combine to achieve a particular function can be considered “associated” with each other such that the desired functionality is achieved, regardless of the architecture or intermediate components. Similarly, any two components so associated can also be considered “connected” or “coupled” with each other to achieve the desired functionality, and any two components capable of being so associated can also be considered “couplable” with each other to achieve the desired functionality. Specific examples of “couplable” include, but are not limited to, physically connectable and / or physically interacting components and / or wirelessly interacting and / or wirelessly interacting components and / or logically interacting and / or logically interacting components.

[0075] It should further be understood that the present invention is defined by the appended claims. Those skilled in the art will understand that, in general, the terms used in this specification, and particularly in the appended claims (e.g., the body of the appended claims), are generally intended as "open" terms (e.g., the term "including" should be interpreted as "including, but not limited to," the term "having" should be interpreted as "having at least," the term "includes" should be interpreted as "includes, but not limited to," etc.). Those skilled in the art will further understand that where a specific number is intended in the introduced claim recitation, such intention will be expressly recited in the claim; in the absence of such recitation, no such intention exists. For example, as an aid to understanding, the following appended claims may include the use of the introductory phrases "at least one" and "one or more" to introduce the claim recitation. However, the use of such phrases should not be construed to mean that the introduction of a claim recitation by the indefinite article "a" or "an" limits any particular claim containing such introduced claim recitation to inventions containing only one such recitation; the same applies to the use of definite articles used to introduce claim recitations, even when the same claim includes the introductory phrases "one or more" or "at least one" and an indefinite article such as "a" or "an" (e.g., "a" and / or "an" should normally be interpreted to mean "at least one" or "one or more"). Moreover, even when a specific number of introduced claim recitations is expressly recited, those skilled in the art will recognize that such a recitation is normally interpreted to mean at least the recited number (e.g., the mere recitation of "two recitations," without any other modifier, normally means at least two recitations, or more than two recitations).Furthermore, when conventional language similar to "at least one of A, B, and C, etc." is used, generally, such a structure is intended in the sense that one of ordinary skill in the art would understand the conventional language (e.g., "a system having at least one of A, B, and C" includes, but is not limited to, a system having only A, only B, only C, A and B together, A and C together, B and C together, and / or A, B, and C together, etc.). When conventional language similar to "at least one of A, B, or C, etc." is used, generally, such a structure is intended in the sense that one of ordinary skill in the art would understand the conventional language (e.g., "a system having at least one of A, B, or C" includes, but is not limited to, a system having only A, only B, only C, A and B together, A and C together, B and C together, and / or A, B, and C together, etc.). Moreover, those skilled in the art will understand that virtually any disjunctive word and / or phrase expressing two or more alternative terms, whether in the description, claims, or drawings, should be understood to contemplate the possibility of including one of the terms, either of the terms, or both terms. For example, the phrase "A or B" would be understood to include the possibilities of "A" or "B" or "A and B."

[0076] The present disclosure and many of its attendant advantages will be understood from the foregoing description, and it will be apparent that various changes in form, construction, and arrangement of the elements can be made without departing from the disclosed subject matter or sacrificing all of its material advantages. The illustrated form is merely illustrative, and it is the intent of the following claims to embrace and include such modifications. It will further be understood that the invention is defined by the appended claims.

Claims

1. a polymer matrix formed by crosslinking a plurality of polymer molecules; a plurality of liquid crystal molecules dispersed within the polymer matrix; and a plurality of getter molecules dispersed within the polymer matrix; An electro-optic modulator comprising: an electro-optic modulator, wherein the plurality of getter molecules and the polymer matrix are each soluble in a solvent, the plurality of getter molecules are insoluble in the plurality of liquid crystal molecules, and each of the plurality of getter molecules comprises a cation and an anion configured to remove one or more cationic impurities disposed within the polymer matrix.

2. 10. The electro-optic modulator of claim 1, wherein the solvent comprises water, the electro-optic modulator comprises a nematic curvilinearly aligned phase (NCAP) film, and the plurality of getter molecules comprise pKa values ​​between 0 and 3.

3. 2. The electro-optic modulator of claim 1, wherein the anion comprises a carboxylate salt group.

4. 4. The electro-optic modulator of claim 3, wherein the plurality of getter molecules comprises one of nicotinic acid or a nicotinate.

5. 4. The electro-optic modulator of claim 3, wherein said plurality of getter molecules comprises ethylenediaminetetraacetic acid (EDTA).

6. 2. The electro-optic modulator of claim 1, wherein the anions comprise phosphate groups.

7. 7. The electro-optic modulator of claim 6, wherein said plurality of getter molecules comprises dihydrogen phosphate.

8. 8. The electro-optic modulator of claim 7, wherein the plurality of getter molecules comprises ammonium dihydrogen phosphate.

9. 2. The electro-optic modulator of claim 1, wherein the anion comprises a sulfonate group.

10. 10. The electro-optic modulator of claim 9, wherein the plurality of getter molecules comprises one of polystyrene sulfonic acid or polystyrene sulfonate.

11. 2. The electro-optic modulator of claim 1, wherein the plurality of getter molecules comprises a chelating agent.

12. 2. The electro-optic modulator of claim 1, wherein said plurality of getter molecules comprises valinomycin.

13. 2. The electro-optic modulator of claim 1, wherein said plurality of getter molecules comprises 0.01 to 1.0 weight percent of said polymer matrix.

14. 2. The electro-optic modulator of claim 1, wherein said polymer matrix, said plurality of liquid crystal molecules, and said plurality of getter molecules form a modulator material layer.

15. 15. The electro-optic modulator of claim 14, further comprising a glass substrate, wherein the modulator material layer is one of coated directly onto the glass substrate or laminated onto the glass substrate.

16. 16. The electro-optic modulator of claim 15, further comprising a dielectric mirror film deposited on the modulator material layer, wherein the plurality of liquid crystal molecules are configured to align to selectively modulate light in response to application of a voltage through the dielectric mirror film.

17. 2. The electro-optic modulator of claim 1, wherein the anions include at least one of phosphate ions, carboxylate ions, sulfate ions, carbonate ions, thiosulfate ions, sulfite ions, acetate ions, or borate ions.

18. 2. The electro-optic modulator of claim 1, wherein the cation is one of hydrogen, ammonium, hydronium, or an organic group.

19. 20. The electro-optic modulator of claim 18, wherein the ammonium is configured to deactivate trap states in the polymer matrix, thereby reducing the threshold field or hysteresis for switching the plurality of liquid crystals.

20. an illumination source configured to generate illumination; a support for the sample; an electro-optic modulator disposed in a path of illumination from the illumination source and separated from the sample by an air gap; polymer matrix, a plurality of liquid crystal molecules dispersed within the polymer matrix; and a plurality of getter molecules dispersed within the polymer matrix; an electro-optical modulator comprising: a plurality of getter molecules and a polymer matrix, each of the plurality of getter molecules being soluble in a solvent, the plurality of getter molecules being insoluble in the plurality of liquid crystal molecules, and each of the plurality of getter molecules comprising a cation and an anion configured to remove one or more cationic impurities of a polymer matrix; An imaging system comprising:

21. 1. A method of manufacturing an electro-optic modulator, comprising: adding a plurality of getter molecules to a solution comprising a plurality of polymer molecules dissolved in a solvent; adding a plurality of liquid crystal molecules to the solution; emulsifying the plurality of liquid crystal molecules in the solution to disperse the plurality of liquid crystal molecules and form a mixture; coating a substrate with the mixture to form a film; drying the film, wherein the film is a polymer matrix formed from the plurality of polymer molecules; the plurality of liquid crystal molecules dispersed within the polymer matrix; and the plurality of getter molecules dispersed within the polymer matrix; wherein the plurality of getter molecules are soluble in the solvent, the plurality of getter molecules are insoluble in the plurality of liquid crystal molecules, and each of the plurality of getter molecules comprises a cation and an anion configured to remove one or more cationic impurities of the polymer matrix; A method comprising:

22. a polymer matrix formed by crosslinking a plurality of polymer molecules; and a plurality of getter molecules dispersed within the polymer matrix; A polymer composition comprising:

1. A polymer composition, wherein the plurality of getter molecules and the polymer matrix are each soluble in a solvent, the solvent comprising water, and each of the plurality of getter molecules comprising a cation and an anion configured to remove one or more cationic impurities disposed within the polymer matrix.

23. 23. The polymer composition of claim 22, wherein the anions comprise at least one of phosphate, carboxylate, sulfate, carbonate, thiosulfate, sulfite, acetate, or borate ions, and the cations comprise at least one of hydrogen, ammonium, hydronium, or an organic group.

24. 24. The polymer composition of claim 23, wherein the plurality of getter molecules comprises at least one of nicotinic acid, nicotinic acid salts, ethylenediaminetetraacetic acid (EDTA), ammonium dihydrogen phosphate, polystyrene sulfonic acid, polystyrene sulfonate, or valinomycin.

25. 25. The polymer composition of claim 24, wherein the plurality of getter molecules comprises 0.01 to 1.0 weight percent of the polymer matrix.

26. 23. The polymer composition of claim 22, wherein the plurality of getter molecules comprises a pKa value of 0-3.

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