Nano- and microscale patterned surfaces for droplet centering

Abstract

Systems and methods for spectrophotometers are described that may utilize ferrules configured to hold a sample test droplet therebetween via surface tension. A light source within the system may shine light onto the test droplet and measure the reflected or refracted light output, which may be useful for various testing and analytical procedures. Nanoscale or microscale structures may be incorporated onto the ferrule to form a hydrophobic or superhydrophobic surface. This helps prevent the test droplet from wetting the ferrule surface, helping to prevent contamination or mixing of test materials. Thus, the ferrule may achieve a certain self-cleaning capability, and test results may be more accurate.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to U.S. Patent Application No. 18 / 077,399, filed December 8, 2022, the entire text of which is incorporated herein by reference.

[0002] The present disclosure relates generally to spectrophotometers, and more particularly to spectrophotometers that use nanoscale and microscale structures on a pedestal to hold a sample droplet in a test radiation path. [Background technology]

[0003] Certain spectrophotometers use an optically coupled ferrule to hold a sample droplet by surface tension. Light is then shone onto the droplet through an optical element coupled to the ferrule. The reflected light can be analyzed to determine certain properties of the sample. Centering the droplet on a given ferrule can be difficult due to the ferrule's surface characteristics, causing the light to pass through the droplet in an unpredictable or undesirable manner. Furthermore, the droplet can be difficult or time-consuming to completely remove from the ferrule after testing. There is a need for improved spectrophotometers that provide improvements to ensure the droplet is centered in the light path and that make the ferrule easier to clean, avoiding potential contamination between tests. Summary of the Invention

[0004] One embodiment of the present disclosure includes a spectrophotometer comprising a first ferrule and a second ferrule, each having a first pedestal and a second pedestal arranged thereon, the first pedestal and the second pedestal being movably coupled such that the first pedestal and the second pedestal are aligned on opposite sides of a sample location, the spectrophotometer further comprising a plurality of nano- or microscale structures formed on the first pedestal or the second pedestal, the plurality of nano- or microscale structures rendering the first pedestal or the second pedestal hydrophobic, and one or more radiation sources optically coupled to one or more of the first pedestal or the second pedestal and configured to excite a test droplet suspended between the first pedestal and the second pedestal at the sample location.

[0005] Another embodiment according to the present disclosure includes a ferrule for use in a spectrophotometer, the ferrule comprising a pedestal configured to receive a droplet of test material thereon and a plurality of nano- or micro-scale structures formed on the pedestal, the plurality of nano- or micro-scale structures rendering the pedestal hydrophobic.

[0006] This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an index of the scope of the claimed subject matter.

[0007] The foregoing has outlined rather broadly the features and technical advantages of the present disclosure so that the detailed description of the embodiments that follow may be better understood. Additional objects and advantages of the present disclosure will be set forth in part in the description that follows, and in part will be obvious from the description, or may be learned by the practice of the present disclosure. The features and advantages of the present disclosure may be realized and obtained by means of the instruments and combinations particularly pointed out in the appended claims. These and other features of the present disclosure will become more fully apparent from the following description and the appended claims, or may be learned by the practice of the disclosure as set forth hereinafter. It should be appreciated by those skilled in the art that the conception and specific embodiments disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present invention. It should also be appreciated by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the present invention as set forth in the appended claims. The novel features believed characteristic of the present invention, both as to its organization and method of operation, together with further objects and advantages, will be better understood from the following description when considered in conjunction with the accompanying drawings. It is to be expressly understood, however, that each of the figures is provided for the purpose of illustration and description only and is not intended as a definition of the limits of the present invention. [Brief explanation of the drawings]

[0008] To explain how the above-mentioned and other advantages and features of the present disclosure can be obtained, a more particular description of the present disclosure, briefly described above, will be rendered by reference to specific embodiments thereof which are illustrated in the accompanying drawings. It will be understood that these drawings depict only typical embodiments of the disclosure and therefore should not be considered as limiting its scope. The present disclosure will be described and explained with additional specificity and detail using the following accompanying drawings: [Figure 1A] 1 illustrates an embodiment of a spectrophotometer according to the present disclosure. [Figure 1B] 1 illustrates an embodiment of a spectrophotometer according to the present disclosure. [Figure 2A] Hydrophilic and hydrophobic surfaces are exemplified. [Figure 2B] Hydrophilic and hydrophobic surfaces are exemplified. [Figure 2C] Hydrophilic and hydrophobic surfaces are exemplified. [Figure 3A] 1 illustrates possible structures for creating hydrophobic and superhydrophobic surfaces according to the present disclosure. [Figure 3B] 1 illustrates possible structures for creating hydrophobic and superhydrophobic surfaces according to the present disclosure. [Figure 3C] 1 illustrates possible structures for creating hydrophobic and superhydrophobic surfaces according to the present disclosure. [Figure 3D] 1 illustrates possible structures for creating hydrophobic and superhydrophobic surfaces according to the present disclosure. [Figure 4] 1 illustrates an embodiment of a ferrule according to the present disclosure. [Figure 5] 1 illustrates an embodiment of a spectrophotometer according to the present disclosure. [Figure 6A] 1 illustrates possible embodiments of pedestals and microscale and nanoscale structures according to the present disclosure. [Figure 6B] 1 illustrates possible embodiments of pedestals and microscale and nanoscale structures according to the present disclosure. [Figure 7A] 1A and 1B show cross-sectional side views of possible pedestal embodiments according to the present disclosure. [Figure 7B] 1A and 1B show cross-sectional side views of possible pedestal embodiments according to the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0009] Before describing embodiments of the present disclosure in detail, it should be understood that the present disclosure is not limited to the parameters of particularly exemplified devices, systems, methods, apparatus, products, processes, and / or kits, which may, of course, vary. Thus, while particular embodiments of the present disclosure will be described in detail with reference to particular configurations, parameters, components, elements, etc., the description is illustrative and should not be construed as limiting the scope of the claimed invention. Additionally, the terminology used herein is for the purpose of describing embodiments and is not necessarily intended to limit the scope of the claimed invention.

[0010] Spectrophotometers provide the ability to shine light or other electromagnetic radiation through a liquid sample, enabling detailed analysis of material composition based on the absorption or transmission of specific wavelengths of radiation. One form of spectrophotometer involves suspending a single droplet of sample material via surface tension between two ferrules or pedestals, each of which can be coupled to one or more radiation or light sources. As used herein, the term ferrule refers to a protective band or ring with an opening disposed around the end of a light source or light guide. In some examples, the light source is coupled to the ferrule via one or more fiber optic cables. The end of the ferrule is referred to herein as the pedestal, and the surface area around the ferrule opening forms the pedestal. The sample droplet may interact with the pedestal during measurements, for example, in addition to the material in and around the ferrule opening. With the sample suspended or held between the ferrules, which may also include extending the length of the suspended sample by moving one or both ferrules away from each other, radiation is transmitted through the sample to perform measurements.

[0011] Ensuring accurate measurements with such spectrophotometers poses several challenges. For example, when placing a sample droplet on a pedestal or ferrule, the droplet may not be centered on the optical aperture, including the pedestal, which can result in noisy data from light scattered at the air-droplet interface. The droplet may have a large sliding angle due to surface tension or other factors, meaning, for example, that a low slope on the pedestal is not sufficient to center the droplet within the pedestal or on the optical aperture. Furthermore, insufficient cleaning of the sample pedestal between measurements can result in cross-contamination. Spectrophotometers are typically manually controlled, which can also introduce additional inconsistencies when a sample is dropped onto a ferrule. Automation of certain steps, such as droplet removal, can help prevent contamination. Furthermore, it would be beneficial to have an innovation that allows for greater elongation of the test droplet held between pedestals via surface tension.

[0012] The techniques of the present disclosure may help address some or all of these issues. One aspect of the present disclosure is to modify the surfaces of the ferrule and / or pedestal, as shown in FIG. 1B and described below, where a test droplet is disposed with a surface pattern on the millimeter, micrometer (one millionth of a meter), and / or nanometer (one billionth of a meter) scale to achieve hydrophobic or superhydrophobic properties on one or both of the pedestal or ferrule. The patterns described herein may utilize small-scale (e.g., millimeter-, micrometer-, or nanometer-scale) structures, at least in terms of height and / or width, and are generally referred to herein as hydrophobic structures, nanostructures, or microstructures. While structures are generally referred to herein as hydrophobic, it should be understood that certain embodiments will achieve superhydrophobic properties. As used herein, hydrophobic means that the outer surface of the fluid droplet has an angle of incidence greater than 90° with the underlying surface, while superhydrophobic means that the outer surface of the fluid droplet has an angle of incidence greater than 150° with the underlying surface. In some cases, these angles can be achieved in part because hydrophobic and superhydrophobic structures can create an air gap beneath the droplet, thereby reducing the contact area of ​​the droplet with the underlying surface, which can reduce the magnitude of the capillary forces that cause the droplet to wet the surface.

[0013] The embodiments and concepts described herein have many advantages. The use of hydrophobic structures can help center a droplet on a pedestal, optical aperture, or other aperture or feature by reducing friction or surface tension that hinders droplet movement. Surfaces with hydrophobic structures can also exhibit self-cleaning properties. A hydrophobic surface that minimizes sample contact with the surface can allow the sample to be more thoroughly removed from the surface after testing, either by spinning, spraying, or wiping, thereby keeping the pedestal surface cleaner. This lower surface contact area of ​​a droplet on a hydrophobic surface can reduce the opportunity for the sample to initially contaminate the ferrule surface. Furthermore, a hydrophobic surface designed for a low sliding angle can aid in automating sample removal from the sample pedestal by tilting the sample pedestal and / or removing the droplet with a puff of air.

[0014] An additional advantage is that the droplet can be further elongated when held by surface tension between two pedestals or ferrules. The longer the droplet is elongated, the longer the path length, making it possible to measure lower concentration samples without the need for a cuvette. Path length, or optical path length, refers to the path length term in Beer's Law, A = εlc, where A = absorbance, ε is the molar attenuation coefficient or absorptivity of the attenuating species, l is the path length, and c is the concentration of the attenuating species. As the path length increases, it becomes more important that the sample be centered relative to the optical aperture or light source so that light passes through the entire sample, not just a portion or edge. If the sample is tilted or off-center, the light will not pass completely through the sample, resulting in errors in the optical absorption measurement. In some cases, there are relatively hydrophilic regions near the optical aperture and relatively hydrophobic regions away from the aperture. Minimizing the droplet's cohesive forces and surface energy tends to attract the droplet to the hydrophilic regions and center it.

[0015] Examples of the present disclosure include ferrules, pedestals, and optional droplet-engaging surfaces that include hydrophobic structures. A preferred embodiment includes a pedestal extending outward from the ferrule, where the pedestal includes a hydrophobic structure. However, other embodiments may not include a pedestal, and the ferrule directly engages the test droplet, also referred to as a sample droplet, and thus includes a hydrophobic structure. The hydrophobic structures described herein may be applied to a variety of surfaces for which it is desirable to achieve hydrophobicity or superhydrophobicity. These ferrules, pedestals, and hydrophobic structures may include metal, stainless steel, glass, plastic, or any suitable material. Ferrules and ferrule pedestals are generally made from stainless steel. Some ferrules incorporate fiber optic cables or other light sources that may utilize the disclosed hydrophobic structures on transparent surfaces, such as glass or plastic types. In some cases, the light source is mounted in the center of the pedestal. Other embodiments utilize a light source embedded in a more peripheral location, such as the outer edge of the ferrule or pedestal. The light source within the spectrophotometer system may also be located in other locations. The type of light / excitation used can be ultraviolet, visible light, or other types of electromagnetic radiation or excitation.

[0016] 1A-1B show a preferred spectrophotometer embodiment 100 according to the present disclosure. The spectrophotometer 100 includes a rotating arm 110, a ferrule 120 and pedestal 122, a table 150, and a display screen 170. The spectrophotometer 100 may include (or be coupled to) a power supply, a server, or other computing device, and / or other components (not shown here). Typically, a user uses a pipette to place a sample droplet 165 on the pedestal 122 and then lowers the rotating arm 110. FIG. 1B shows the pedestal 122, upper ferrule 115, upper pedestal 117, and sample droplet 165 after the rotating arm 110 has been lowered. The sample droplet 165 is held in place by surface tension between the pedestal 122 and the upper pedestal 117. The preferred location for the sample droplet 165 is the center of the pedestals 117, 122. The pedestal 122 and / or the upper pedestal 117 may include a light source or radiation source, such as the tip of a fiber optic cable held by the ferrule 115 or ferrule 120. The fiber optic cable may direct a radiation source through the sample droplet 165 for testing and inspection purposes; light passes from one ferrule, through the droplet, and into a receptor, transducer, or detector (i.e., photodiode, metal-semiconductor-metal photodetector, photoconductive detector, metal-oxide-semiconductor field-effect transistor, photodiode array, charge injection device, charge-coupled device) or other mechanism in the other ferrule; the transmitted light may be processed to determine characteristics of the droplet. The light source or radiation source may shine light through or otherwise excite the droplet 165. The level of light or excitation may be of the type or amount required for optical spectroscopy. In embodiments with a fiber optic cable, openings in the ferrules 115, 120 may allow the fiber optic cable to pass through. The transparent portions of the pedestals 117, 122 form an optically transparent path from the light source through the fiber optic cable, allowing photons to travel to the sample droplet and then into the opposing ferrule. Other embodiments may include other types of light sources, which may be located within the pedestals 117, 122 and / or ferrules 115, 120, and / or at other locations in the system.

[0017] A preferred embodiment of the spectrophotometer includes one or two ferrules 115, 120, with pedestals 117, 122 located on top (or closer to the sample droplet 165). In some embodiments, one or both pedestals may not be necessary. Such embodiments may include only ferrules 115, 120, with the hydrophobic structures described herein included on the surface of the ferrules themselves, instead of on the surface of the pedestals. The concepts described herein remain the same regardless of whether the hydrophobic structures are on the surface of the pedestals or the surface of the ferrules.

[0018] In certain embodiments, any or all of the upper pedestal / ferrule combination 115, 117, or the lower ferrule / pedestal combination 120, 122, or the rotating arm 110 and / or table 150 may be movable relative to the other components. Relative motion of the opposing components allows for small vertical displacements that are used to elongate the test droplet. Because the hydrophobic structures better align the droplet and reduce the contact area between the droplet and the ferrule or pedestal, the droplet may be elongated further than in a device that does not employ the hydrophobic structures described herein.

[0019] In a preferred embodiment, the surfaces of the pedestals 117, 122 are flat and parallel to one another. The ferrules 115, 120 can also have flat and parallel surfaces. However, certain embodiments can include non-flat pedestals and / or ferrules. One such embodiment is described below with respect to FIGS. 7A and 7B. In other embodiments, one of the pedestals can be convex and the other can be concave, or vice versa. This concave / convex configuration can be most beneficial when the surface having the hydrophobic structure is coupled to or includes an optical window having an optical lens with a surface curvature. These concave and convex surfaces would ideally have the same curvature (and still be largely parallel) so that very small path lengths can be achieved. In certain embodiments, the edges of the pedestals 117, 122 or ferrules 115, 120 can be chamfered.

[0020] Figures 2A-2C show the behavior of a droplet on hydrophilic, hydrophobic, and superhydrophobic surfaces, respectively. While Figures 2A-2C show the behavior of a single droplet, they also illustrate how groups of liquids, particularly water, behave. Hydrophilic (attractive to water) surfaces behave like most surfaces encountered in everyday life. For example, water spilled on a table spreads and flattens. On hydrophobic (water-repellent) surfaces, the angle of the surface relative to the rising edge of the droplet is greater than 90°. On superhydrophobic (very water-repellent) surfaces, the angle is greater than 150°.

[0021] Hydrophobicity and superhydrophobicity can be achieved by incorporating small-scale structures onto the pedestal or ferrule shown in Figures 1A-1B. Some illustrations of possible structures are shown in Figures 3A-3D. Test droplets 310a-d are shown in each of Figures 3A-3D. In Figure 3A, a flat surface 340a exhibits hydrophilic behavior. In Figure 3B, nanostructures 340b exhibit superhydrophobic behavior. In Figure 3C, microstructures 340c exhibit superhydrophobic behavior. In Figure 3D, a hierarchical structure (a combination of microstructures and nanostructures) 340d exhibits superhydrophobic behavior.

[0022] The behavior shown in Figures 2B-2C and 3B-3D demonstrates that hydrophobic and superhydrophobic surfaces can help control the behavior and positioning of droplets on surfaces, such as the surface of a pedestal. Hydrophobic structures also help reduce friction, allowing droplets to move more easily across the surface. A low sliding angle allows for easier droplet movement, such as removing a droplet from a pedestal by tilting it, without leaving residue.

[0023] The exact shapes shown in Figures 3B-3D may not achieve superhydrophobic behavior in all possible embodiments. The material composition of structures 340b-340d can affect hydrophobicity. Another variable can be the material composition of sample droplets 310b-310d. The carrier fluid is often water but may "carry" a variety of materials for testing. The exact material composition of the fluid, test material, and other factors such as humidity and atmospheric pressure can all affect hydrophobicity in any particular situation.

[0024] The present disclosure is intended to encompass various implementations of hydrophobic structures, including various sizes, shapes, patterns, symmetries, and asymmetries. The present disclosure is not limited to any particular pattern or shape. Applicants have found that hierarchical structures, or a combination of microscale and nanoscale features, tend to be more effective in achieving hydrophobicity and superhydrophobicity. This is for several reasons. Nanoscale features are not typically considered robust surfaces. Having a hierarchy of scale structures (e.g., a microscale pattern with nanoscale features therein) has been shown to create a more mechanically robust surface that can retain superhydrophobic properties for longer than surfaces with nanoscale features alone. This robustness is highly attractive for surfaces with repeated customer interaction. Furthermore, the hydrophobicity of a surface is also driven by the chemical properties of the material from which the surface is made and the surface topography. If the surface topography is such that a liquid droplet does not wet the surface (i.e., there are air gaps between the surface and the liquid droplet), the contact angle will be higher. The combination of a hydrophobic material and a surface topography (microscale and nanoscale) that prevents droplet wetting is more predictably superhydrophobic.

[0025] A nanoscale structure is defined as an element having at least one dimension between 1 and 100 nanometers. In some embodiments, the nanoscale structure may comprise a nanomaterial, molecular surface functionalization (such as a physical or chemical treatment), or nanoscale topographical features. In some embodiments, the nanoscale structure may be created by the addition or removal of material from the pedestal or ferrule. In some embodiments, the nanoscale structure may comprise a spherical, rod-like, faceted, needle-like, cubic, triangular, hexagonal, amorphous, or any combination thereof. In some embodiments, the nanoscale feature may be a void. In some embodiments, the nanoscale feature may comprise a single nanoscale structure or an aggregate of nanoscale structures. In some embodiments, the nanoscale feature is made from the same material as the pedestal or ferrule. In other embodiments, the nanoscale feature is made from a different material than the material of the pedestal or ferrule. In some embodiments, the nanoscale feature is attached to the ferrule or pedestal by covalent, ionic, metallic, hydrogen, or van der Waals forces. In other embodiments, the nanoscale features are non-specifically attached to the surface of the pedestal or ferrule.

[0026] Microscale structures are defined as elements having at least one dimension between 1 and 100 micrometers. In some embodiments, the microscale structures are on the surface of a ferrule or pedestal. In some embodiments, the microscale structures may be created by adding or removing material from the pedestal or ferrule. In some embodiments, the microscale structures form a lattice, stripes, weave, stars, dots, checkerboards, concentric circles, chevrons, spirals, or irregular patterns. In some embodiments, the microscale structures may include structures in one or more axes, e.g., X, Y, and Z, of the surface of the ferrule or pedestal. In some embodiments, the microscale structures form voids in the surface of the ferrule or pedestal, which may be hemispherical, pyramidal, or cubic.

[0027] In one embodiment, the microscale structure may be modified with nanoscale structures. In some embodiments, the nanoscale features are bonded to the microscale structure by covalent, ionic, metallic, hydrogen, or van der Waals forces. In other embodiments, the nanoscale features are non-specifically bonded to the microscale structure. In some embodiments, the microscale structures are made from the same material as the nanoscale structures. In other embodiments, the nanoscale structures are made from a different material. In other embodiments, the nanoscale structures are located within the pattern of the microscale features.

[0028] FIG. 4 illustrates one possible embodiment of a ferrule 410 according to the present disclosure, such as the fixed pedestal 120 and / or the top pedestal 115 of FIGS. 1A-1B. The ferrule 410 may include multiple structures 450 formed on an optical component disposed within the ferrule 410. Each of the structures 450 may be small in scale (e.g., microscale, nanoscale, or hierarchical). The structures 450 may be shaped or patterned to aid in centering a droplet over an opening 420 (or another desired location) formed within the ferrule 410, which may contain a light source. These structures 450 may also be formed over all or a portion of the pedestal 415 of the ferrule 410, as well as over an optical component disposed within the opening 420. In certain embodiments, the opening 420 may include a transparent optical interface that allows illumination of a test droplet disposed thereon. The pedestal or other portions of the ferrule may be formed, for example, from stainless steel. While the description refers to an optical fiber within the ferrule, other embodiments are possible. Ferrule embodiments may include an optical window or lens disposed within the aperture that allows the light source to pass light through. Such optical windows may include glass, fused silica, BK7 glass, or other transparent substrates that allow light to pass from the transmitting ferrule through the sample and into the receiving ferrule. Such embodiments may employ hydrophobic structures to improve hydrophobicity.

[0029] Referring again to FIG. 4 , once a test droplet is placed on the ferrule 410, the structure 450 can provide hydrophobic or superhydrophobic properties, which in some embodiments can help center or align the test droplet in a preferred location, among other benefits. The hydrophobic structure can help ensure that all of the droplet reaches the center of the pedestal / ferrule rather than getting stuck elsewhere in the pedestal or ferrule. This can prevent the test droplet from pooling on the surface 415. The test droplet can then be placed, such as by tilting the ferrule 410, so that all of the test droplet rolls off the ferrule 410 and no material remains. The contact area between the test droplet and the ferrule 410 will be reduced. Automation can also be incorporated into the spectrophotometer for tilting the ferrule 410 to place the test droplet after the test is complete. Because the test droplet does not adhere to the surface 415, it can be more easily centered on the ferrule 410. This may aid in more accurate and consistent testing.

[0030] Embodiments according to the present disclosure may implement a variety of tilt angles for placing the test droplet. The sliding angle for small droplets with hydrophobic surfaces may vary, such as from 0° to 50° from horizontal, although larger angles may be used. The exact sliding angle required may depend on several factors: the droplet material, the pedestal material, the droplet volume, and the pattern and / or shape of the hydrophobic structure.

[0031] FIG. 5 illustrates another embodiment of a spectrophotometer 500 according to the present disclosure. The spectrophotometer includes a screen / user interface 570, a rotating arm 510, a surface 550, and a lower arm 520. The spectrophotometer 500 includes a processor 580 and a memory 590 coupled to each other by a bus 585. In some embodiments, the processor 580 and / or the memory 590 may comprise part of a server or computing device remote from the spectrophotometer 500. The spectrophotometer 500 may be at least partially automated via a rotating shaft 530 coupled to the surface 550 and the lower arm 520. During droplet testing, the rotating shaft 530 may be actuated (e.g., by the processor 580 or a user) to rotate the droplets and allow them to flow into a waste or other collection device. The rotating shaft 530 may be implemented to rotate the lower arm 520 alone or to rotate the entire unit including the lower arm 520 and the rotating arm 510.

[0032] The spectrophotometer 500 may be coupled to or include additional components, such as a desktop computer, server, personal computing device, laptop, smart device, or other computing device. Coupling between the controller spectrophotometer 500 or processor 580 and other components may be wired or wireless, such as via Wi-Fi or Bluetooth. The bus 585 may further couple the processor 580 and memory 590 to other components, such as a user interface 570, a rotating arm 510, a lower arm 520, and a power supply (not shown). The user interface 570 may allow a user to input information to or receive information from the processor 580 or memory 590. Additional components, such as a touch screen, keyboard, or mouse, may add to the functionality of the user interface 570. The power source may include a battery or an external power source (e.g., an electrical outlet), or other power source. The memory 590 may include random access memory (RAM), read-only memory (ROM), an optical disk, a hard disk, a flash drive, or the like. Memory 590 may include one or more application programs, such as an operating system, a web browser application, or other applications, and associated data. Memory 590 may enable processor 580 to perform various actions, including accessing instructions, application programs, etc. stored on a temporary or non-transitory memory medium to offload data or upload data. Processor 580 may perform and / or enable a user to perform at least a portion of any of the method embodiments described herein.

[0033] FIGS. 6A-6B illustrate possible pedestal embodiments with different patterns of hydrophobic structures according to the present disclosure. Each pedestal 700a, 700b has a chamfer 740 surrounding a light source or opening 720. The light source 720 may be, for example, the end of a fiber optic cable. A pattern of hydrophobic structures 730 surrounds the light source 720 within the chamfer 740. In FIG. 6A, the hydrophobic structures 730 are divided into a radial pattern 750a. In FIG. 6B, the hydrophobic structures 730 are less resolved and include a bull's-eye pattern 750b. Areas of the pedestal 700a / b without the hydrophobic structures 730 may be hydrophilic (water-loving) in some embodiments. Other patterns are also possible. The patterns shown here may help center the droplet (often directly above the light source) so that it is centered over the light source 720 or otherwise aligned and positioned in the most desirable location for accurate testing. To aid in centering, the pedestals 700a, 700b may be tilted downward toward the light source. The tilt may be very small, for example, 0°-5°, or may be greater in certain embodiments. The hydrophobic structure 730 and patterns 750a, 750b may aid in centering the droplet.

[0034] Generally, in both Figures 6A and 6B, there are more hydrophobic structures 730 outward from the light source 720. Near the light source 720, there are fewer hydrophobic structures 730. This can help cause a droplet to move when placed on an area 730 with many hydrophobic structures and to become more stationary in areas 730 with fewer hydrophobic structures, such as the center near the light source 720. When a droplet is placed on the pedestals 700a, 700b, the hydrophobic structures 730 help prevent the droplet from sticking to the pedestals 700a, 700b, leaving less residue on other portions of the pedestals 700a, 700b. The hydrophobic structures 730 in both pedestals 700a, 700b are arranged in a small square pattern. However, other patterns and sizes are possible, including circles, arcs, rectangles, triangles, trapezoids, hierarchical structures, micrometer-scale, millimeter-scale, nanometer-scale, other shapes and styles, and various combinations of any of the foregoing. It should be noted that the pattern of the hydrophobic structure regions 750a, 750b can include various shapes and patterns (e.g., radial vs. bull's-eye). Also, the hydrophobic structure 730 can include various shapes and patterns. This disclosure is not limited to any particular pattern or shape. The hydrophobic structure 730 can cover 20%, 30%, 40%, 50%, or more of the pedestal surface. As previously mentioned, the exemplary embodiment can alternatively be applied to a ferrule without a pedestal.

[0035] 7A and 7B illustrate possible pedestal embodiments according to the present disclosure. These figures show cross-sectional views of ferrules 810a / b and pedestals 815a / b. In a typical fabrication example, as described with reference to FIG. 7A, the fiber optic ferrule 810a is very finely polished to optimize the optical output of the fiber optic cable 820a when it is attached to the fiber optic cable 820a. This functionally means that the ferrule 810a and the fiber optic cable 820a are very flat in the area surrounding the fiber optic cable 820a without further modification. In one practical approach to this technique, the ferrule 810a and, for example, the glass fiber optic cable 820a are polished together for optimal optical output before hydrophobic structures 850a are added for hydrophobicity. These structures 850a are preferably added to stainless steel in the area surrounding the fiber optic opening, i.e., the pedestal 815a. In this embodiment, areas of greater or lesser hydrophobicity can help center the droplet. In some cases, there may be relatively hydrophilic regions near the openings and relatively hydrophobic regions away from the openings. Minimization of the cohesive forces and surface energy of droplet 860a attracts droplet 860a to the hydrophilic regions, centering it.

[0036] In another embodiment shown in FIG. 7B , there may be a “cap” 875 that is independently patterned with hydrophobic structures 850b and then added in a separate step to the top of the upper flat surface of the ferrule 810b, forming a pedestal 815b. The cap 875 may be made from the same list of materials from which the ferrule 810b may be made (e.g., stainless steel, glass, plastic, etc.). The cap has an opening concentric with the fiber optic cable 820b opening in the ferrule 810b. The cap 875 may have a sloped surface 870 that slopes down to the fiber optic opening. The hydrophobic structures 850b may reside on the sloped surface 870 to leverage a lower sliding angle to center the droplet 860b. The bottom of the sloped surface 870 may be relatively hydrophilic to promote droplet 860b remaining in place. One concern with this embodiment is that the interface between the cap 875 and the ferrule 810b surface may be more likely to attract or nucleate air bubbles. In some embodiments, it is possible to dispense with a separate "cap" material and use surface modification techniques to create the slope toward the optical fiber aperture. However, one drawback is that available techniques for surface patterning (e.g., focused ion beam) can take a very long time to remove several millimeters of material to form the slope.

[0037] As described herein, there are various techniques and manufacturing processes by which hydrophobic structures can be fabricated or added to ferrules or pedestals. Some possible techniques include laser etching, photolithography, laser lithography and other laser-based surface treatment processes, gas or liquid phase chemical etching, focused ion beam etching, atomic layer deposition, chemical vapor deposition, focused ion beam deposition, (high-energy) electron beam lithography, annealing, and hot embossing. The technique selected may depend on the size scale of the desired features and the material to be patterned. To achieve each desired size scale, a sequential combination of techniques may be used. For example, photolithography may be used to create millimeter-scale features, and electron beam lithography or focused ion beam etching may be used to create nanoscale features. Materials used for hydrophobic structures include stainless steel, glass, plastic, composites, alloys, iron alloys, aluminum alloys, fused silica, ceramics, and any other suitable materials.

[0038] Example 1 is a spectrophotometer including a first ferrule and a second ferrule, each including a first pedestal and a second pedestal, movably coupled to each other so that the first pedestal and the second pedestal are aligned on opposite sides of a sample position; a plurality of nano- or microscale structures formed on the first pedestal or the second pedestal, the plurality of nano- or microscale structures rendering the first pedestal or the second pedestal hydrophobic; and one or more radiation sources optically coupled to one or both of the first ferrule and the second ferrule and configured to excite a droplet held between the first pedestal and the second pedestal at the sample position.

[0039] Example 2 includes the subject matter of Example 1, and further specifies that the plurality of nano- or microscale structures includes one or more of: a plurality of nanometer-scale structures; a plurality of micrometer-scale structures; one or more irregularly shaped structures; and one or more hierarchical structures.

[0040] Example 3 includes the subject matter of any of Examples 1-2, further specifying that the second pedestal includes a plurality of nano- or micro-scale structures.

[0041] Example 4 includes the subject matter of any of Examples 1-3, and further specifies that at least one of the first pedestal and the second pedestal includes both nanoscale and microscale structures.

[0042] Example 5. The spectrophotometer of any one of claims 1-4, further specifying that the first pedestal or second pedestal including a plurality of nano- or microscale structures includes more nano- or microscale structures around their periphery and fewer nano- or microscale structures near their center.

[0043] Example 6 includes the subject matter of any of Examples 1-5, further specifying that the plurality of nano- or microscale structures are configured to generate an angle of incidence between the droplet and the ferrule or pedestal that is greater than 150°.

[0044] Example 7 includes the subject matter of any of Examples 1-6, further specifying that the one or more radiation sources are optically coupled to one or more fiber optic cables in the first ferrule operable to emit light through the first pedestal, the emitted light passing through the droplet and into a receptor in the second ferrule.

[0045] Example 8 includes the subject matter of any of Examples 1-7, and further specifies that the plurality of nano- or microscale structured materials includes one or more of the following: stainless steel, glass, a composite material, an iron alloy, and an aluminum alloy.

[0046] Example 9 includes any subject matter of example 7, further specifying that the first ferrule and / or the second ferrule are movable to adjust the optical path length of the spectrometer.

[0047] Example 10. A ferrule for use in a spectrophotometer, the ferrule comprising: a pedestal configured to receive a droplet of test material thereon; and a plurality of nano- or microstructures formed on the pedestal, the plurality of nano- or microstructures rendering the pedestal hydrophobic.

[0048] Example 11 includes any of the subject matter of Example 10, further specifying that the pedestal is configured to hold the droplet in place via surface tension in combination with the second ferrule.

[0049] Example 12 includes the subject matter of any of Examples 10-11, further specifying that the ferrule is further coupled to one or more radiation sources configured to excite the droplets on the pedestal.

[0050] Example 13 includes any of the subject matter of Example 12, further specifying that the one or more radiation sources are disposed at an outer edge of the pedestal.

[0051] Example 14 includes any subject matter of Example 12, further specifying that the one or more radiation sources are configured to transmit at least one of ultraviolet and visible light.

[0052] Example 15 includes any subject matter of Example 12, further specifying that the one or more radiation sources comprise a single radiation source at the center of the pedestal, and the plurality of nano- or microstructures comprise a bull's-eye pattern around the single radiation source.

[0053] Example 16 includes any subject matter of Example 12, further specifying that the one or more radiation sources comprise a single radiation source at a center of the pedestal, and the plurality of nano- or microstructures comprise a radial pattern around the single radiation source, each segment of the radial pattern tapering toward the center of the pedestal.

[0054] Example 17 includes any subject matter of example 12, further specifying that the plurality of nano- or microstructures are formed surrounding the opening in the pedestal.

[0055] Example 18 includes any subject matter of example 17, further specifying that the plurality of nano- or microstructures further centers the droplet in the aperture.

[0056] Example 19 includes the subject matter of any of Example 17, further specifying that the aperture is an optical aperture for coupling an optical fiber.

[0057] Example 20 includes the subject matter of any of Examples 10-19, further specifying that the plurality of structures includes at least one of a glass structure, a plastic structure, and a metal structure.

[0058] Example 21 includes the subject matter of any of Examples 10-20, further specifying that the pedestal is configured to receive a droplet having a volume of, for example, 0.5-5 μL.

[0059] Example 22 includes the subject matter of any of Examples 12-21, and further specifies that the surface of the pedestal is flat or curved.

[0060] Example 23. A method for analyzing a test droplet, the method comprising: placing the test droplet at a sample position of a first ferrule having a first pedestal; moving a second ferrule having a second pedestal so that the first pedestal and the second pedestal are aligned on opposite sides of the sample position and engaging the test droplet to hold the test droplet between the first ferrule and the second ferrule, wherein one or both of the first pedestal and the second pedestal include a plurality of nano- or microscale structures, the plurality of nano- or microscale structures rendering the first pedestal or the second pedestal hydrophobic; irradiating the test droplet with one or more radiation sources, the one or more radiation sources optically coupled to one or both of the first ferrule and the second ferrule and configured to excite with light the test droplet held between the first pedestal and the second pedestal at the sample position; and detecting light transmitted through the test droplet.

[0061] Example 24 includes the subject matter of Example 23, and further includes positioning the sample by tilting the first ferrule to slide the test droplet off the first pedestal.

[0062] Abbreviation list of defined terms To aid in understanding the scope and content of this written description and the appended claims, a selection of terms are directly defined below. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains.

[0063] As used herein, the terms "approximately," "about," and "substantially" refer to an amount or condition that is close to a particular stated amount or condition that still performs a desired function or achieves a desired result. For example, the terms "approximately," "about," and "substantially" can refer to an amount or condition that deviates from the specifically stated amount or condition by less than 10%, or less than 5%, or less than 1%, or less than 0.1%, or less than 0.01%.

[0064] Various aspects of the present disclosure, including devices, systems, and methods, may be illustrated with reference to one or more embodiments or implementations that are exemplary in nature. As used herein, the term "exemplary" means "serving as an example, instance, or illustration" and should not necessarily be construed as preferred or advantageous over other embodiments disclosed herein. In addition, reference to an "implementation" of the disclosure or invention includes specific reference to one or more embodiments thereof, and vice versa, and is intended to provide illustrative examples without limiting the scope of the invention, which is set forth in the appended claims rather than the following description.

[0065] As used herein, unless otherwise understood or stated, implicitly or explicitly, words appearing in the singular include their plural equivalents, and words appearing in the plural include their singular equivalents. Accordingly, it should be noted that, as used in this specification and the appended claims, the singular forms "a," "an," and "the" include plural referents unless the content clearly dictates otherwise. For example, a reference to a single referent (e.g., "widget") includes one, two, or more referents unless otherwise understood or stated, implicitly or explicitly. Similarly, a reference to a plural referent should be construed as including a single referent and / or multiple referents unless the content and / or context clearly dictates otherwise. For example, a reference to a plural referent (e.g., "widgets") does not necessarily require that a plurality of such referents exist. Instead, it will be understood that one or more referents are contemplated herein, regardless of the presumed number of referents, unless otherwise specified.

[0066] As used herein, directional terms such as "top," "bottom," "left," "right," "up," "down," "upper," "lower," "proximal," "distal," and the like, are used herein for relative orientation purposes only and are not intended to otherwise limit the scope of the disclosure or claimed invention(s).

[0067] conclusion Unless otherwise understood or stated implicitly or explicitly, it is understood that for any given component or embodiment described herein, any of the possible candidates or alternatives listed for that component may generally be used individually or in combination with each other. Additionally, unless otherwise understood or stated implicitly or explicitly, it will be understood that any listing of such candidates or alternatives is merely illustrative and not limiting.

[0068] Additionally, unless otherwise indicated, numbers expressing quantities, components, distances, or other measurements used in the specification and claims should be understood as modified by the term "about." Accordingly, unless indicated to the contrary, the numerical parameters set forth in the specification and appended claims are approximations that may vary depending upon the desired properties sought to be obtained by the subject matter presented herein. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter should at least be construed in light of the number of reported significant digits and by applying ordinary rounding techniques. Notwithstanding that the numerical ranges and parameters setting forth the broad scope of the subject matter presented herein are approximations, the numerical values ​​set forth in the specific examples are reported as precisely as possible. However, any numerical value inherently contains certain errors necessarily resulting from the standard deviation found in their respective testing measurements.

[0069] The headings and sub-headings used herein are for organizational purposes only and are not meant to be used to limit the scope of the specification or the claims.

[0070] The terms and expressions used in this specification are used as terms of description and not of limitation, and are not intended to exclude equivalents of the features shown and described or portions thereof, but it is understood that various modifications are possible within the scope of the invention described in the sections. While the present invention has been specifically disclosed above, in part, using preferred embodiments, exemplary embodiments, and optional features, it should be understood that those skilled in the art may anticipate modifications and variations of the concepts disclosed herein, and such modifications and variations are deemed to be within the scope of the invention as defined by the accompanying sections. The specific embodiments provided herein are examples of useful embodiments of the present invention, and various changes and / or modifications of the features of the invention exemplified herein, as well as further applications of the principles exemplified herein that may occur to those skilled in the relevant art, can be made to the exemplified embodiments without departing from the spirit and scope of the invention as defined by the sections, and should be deemed to be within the scope of this disclosure.

[0071] It will also be understood that systems, devices, articles of manufacture, kits, methods, and / or processes according to certain embodiments of the present disclosure may include, incorporate, or otherwise comprise properties or features (e.g., components, members, elements, parts, and / or portions) described in other embodiments disclosed and / or described herein. Thus, various features of particular embodiments may be compatible with, combined with, included in, and / or incorporated into other embodiments of the present disclosure. Thus, the disclosure of a particular feature in connection with a particular embodiment of the present disclosure should not be construed as limiting the application or inclusion of that feature to the particular embodiment. Rather, it will be understood that other embodiments may include such features, members, elements, parts, and / or portions without necessarily departing from the scope of the present disclosure.

[0072] Furthermore, unless a feature is described as requiring another feature in combination, any feature herein may be combined with any other feature of the same or different embodiments disclosed herein. Moreover, various well-known aspects of example systems, methods, devices, etc. have not been described in particular detail herein to avoid obscuring aspects of the example embodiments. However, such aspects are also contemplated herein.

[0073] All references cited in this application are incorporated herein by reference in their entirety to the extent they do not contradict the disclosure of this application. It will be apparent to those skilled in the art that methods, devices, device elements, materials, procedures, and techniques other than those specifically described herein can be applied to the practice of the invention broadly disclosed herein without resort to undue experimentation. All art-known functional equivalents of the methods, devices, device elements, materials, procedures, and techniques specifically described herein are intended to be encompassed by this invention.

[0074] When a group of materials, compositions, ingredients, or compounds is disclosed herein, it is understood that all individual members of that group and all subgroups thereof are separately disclosed. When a Markush group or other group is used herein, all individual members of the group and all possible combinations and subcombinations of the group are intended to be individually included in the disclosure. All formulations or combinations of components described or exemplified herein may be used to practice the invention, unless otherwise specified. Whenever a range, such as a temperature range, time range, or composition range, is given in the specification, all intermediate ranges and subranges, as well as all individual values ​​included in the given range, are intended to be included in the disclosure. All variations that fall within the meaning and range of equivalents of the terms are to be embraced within those ranges.

[0075] While the present invention and its advantages have been described in detail, it should be understood that various changes, substitutions, and alterations can be made therein without departing from the spirit and scope of the invention, as defined by the appended claims. Moreover, the scope of this application is not intended to be limited to the particular embodiments of the processes, machines, manufacture, compositions of matter, means, methods, and steps described herein. As those skilled in the art will readily appreciate from this disclosure, any now-existing or later-developed processes, machines, manufacture, compositions of matter, means, methods, or steps that perform substantially the same function or achieve substantially the same results as the corresponding embodiments described herein can be utilized in accordance with the present invention. Accordingly, it is intended that the appended claims include within their scope such processes, machines, manufacture, compositions of matter, means, methods, or steps.

Claims

1. 1. A spectrophotometer comprising: a first ferrule and a second ferrule, each including a first pedestal and a second pedestal, the first ferrule and the second ferrule being movably coupled such that the first pedestal and the second pedestal are aligned on opposite sides of a sample position; a plurality of nano- or micro-scale structures formed on the first pedestal or the second pedestal, the plurality of nano- or micro-scale structures rendering the first pedestal or the second pedestal hydrophobic; and one or more radiation sources optically coupled to one or both of the first ferrule and the second ferrule and configured to excite a droplet held between the first pedestal and the second pedestal at the sample location.

2. 10. The spectrophotometer of claim 1, wherein the plurality of nano- or microscale structures comprises one or more of: a plurality of nanometer-scale structures; a plurality of micrometer-scale structures; one or more irregularly shaped structures; and one or more hierarchical structures.

3. The spectrophotometer of claim 1 , wherein the second pedestal includes the plurality of nano- or micro-scale structures.

4. The spectrophotometer of claim 1 , wherein at least one of the first pedestal and the second pedestal includes both nano- and micro-scale structures.

5. 2. The spectrophotometer of claim 1, wherein the first pedestal or the second pedestal containing the plurality of nano- or microscale structures includes more nano- or microscale structures around their periphery and fewer nano- or microscale structures near their center.

6. The spectrophotometer of claim 1 , wherein the plurality of nano- or microscale structures are configured to create an angle of incidence between the droplet and the ferrule or pedestal that is greater than 150°.

7. 2. The spectrophotometer of claim 1, wherein the one or more radiation sources are optically coupled to one or more fiber optic cables in the first ferrule operable to emit light through the first pedestal, the emitted light passing through the droplet and into a receptor in the second ferrule.

8. 8. The spectrophotometer of claim 1, wherein the material of the plurality of nano- or micro-scale structures comprises one or more of the following: stainless steel, glass, composite material, iron alloy, aluminum alloy.

9. The spectrophotometer of claim 7 , wherein the first ferrule and / or the second ferrule are movable to adjust the optical path length of the spectrometer.

10. 1. A ferrule for use in a spectrophotometer, comprising: a pedestal configured to receive a droplet of test material thereon; a plurality of nano- or microstructures formed on the pedestal, the plurality of nano- or microstructures rendering the pedestal hydrophobic.

11. The ferrule of claim 10, wherein the pedestal is configured to hold the droplet in place via surface tension in combination with a second ferrule.

12. The ferrule of claim 10 , wherein the ferrule is further coupled to one or more radiation sources configured to excite the droplet on the pedestal.

13. The ferrule of claim 12 , wherein the one or more radiation sources are disposed on an outer edge of the pedestal.

14. 13. The ferrule of claim 12, wherein the one or more radiation sources are configured to transmit at least one of ultraviolet and visible light.

15. 13. The ferrule of claim 12, wherein the one or more radiation sources comprise a single radiation source at a center of the pedestal, and the plurality of nano- or microstructures comprise a bull's-eye pattern around the single radiation source.

16. 13. The ferrule of claim 12, wherein the one or more radiation sources comprise a single radiation source at a center of the pedestal, and the plurality of nano- or microstructures comprise a radial pattern around the single radiation source, each segment of the radial pattern tapering toward the center of the pedestal.

17. The ferrule of claim 12 , wherein the plurality of nano- or microstructures are formed surrounding an opening in the pedestal.

18. 18. The ferrule of claim 17, wherein the plurality of nano- or microstructures further centers the droplet in the opening.

19. 18. The ferrule of claim 17, wherein the opening is an optical opening for coupling an optical fiber.

20. 11. The ferrule of claim 10, wherein the plurality of nano- or microstructures comprises at least one of a glass structure, a plastic structure, and a metal structure.

21. The ferrule of claim 10, wherein the pedestal is configured to receive the droplet having a volume of 0.5 to 5 μL.

22. The ferrule according to any one of claims 12 to 21, wherein the surface of the pedestal is flat or curved.

23. 1. A method of analyzing a test droplet, comprising: placing a test droplet on a sample location of a first ferrule having a first pedestal; moving a second ferrule having a second pedestal such that the first pedestal and the second pedestal are aligned on opposite sides of the sample location and engage the test droplet to hold the test droplet between the first ferrule and the second ferrule, wherein one or both of the first pedestal and the second pedestal include a plurality of nano- or microscale structures, and the plurality of nano- or microscale structures render the first pedestal or the second pedestal hydrophobic; illuminating the test droplet with one or more radiation sources optically coupled to one or both of the first ferrule and the second ferrule and configured to excite with light the test droplet held between the first pedestal and the second pedestal at the sample location; and detecting the light transmitted through the test droplet.

24. 24. The method of claim 23, further comprising positioning the sample by tilting the first ferrule to slide the test droplet off the first pedestal.

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