Medical Articles Having Microstructured Surfaces

Abstract

A medical diagnostic device or component thereof is described that includes a microstructured surface including peak structures and adjacent valleys, where the valleys have a maximum width in the range of 1 to 1000 microns, and the peak structures. In some embodiments (e.g., to improve cleanability), the peak structures of the microstructured surface have a sidewall angle greater than 10 degrees. The peak structures may include two or more facets, such as in the case of a linear array of prisms or an array of cube-corner elements. The microstructured surface of a medical diagnostic device typically comes into contact with multiple patients during normal use of the device, such as a stethoscope diaphragm. The microstructured surface exhibits improved microbial (e.g., bacterial) removal upon cleaning and / or results in reduced contact transfer of microorganisms. Methods of manufacture and use are also described.

Description

[Background technology]

[0001] U.S. Patent Application Publication No. 2017 / 0100332 (Abstract) describes an article comprising a first plurality of spaced features. The spaced features are arranged in groups, each group of features includes repeating units, and the spaced features within a group are spaced at an average distance of approximately 1 nanometer to approximately 500 micrometers apart, each feature has a surface substantially parallel to the surface on the adjacent feature, each feature is separated from its adjacent feature, and the groups of features are arranged relative to each other to define a meandering path. The plurality of spaced features result in an article with a machining roughness index of approximately 5 to approximately 20.

[0002] International Publication Nos. 2013 / 003373 and 2012 / 058605 describe surfaces for resisting and reducing biofilm formation, particularly on medical articles. The surfaces include multiple microstructural features. [Overview of the Initiative]

[0003] Articles with specific microstructural features are useful in reducing the initial formation of biofilms, particularly in the case of medical articles; however, such microstructured surfaces can be difficult to clean. This is presumably because, at least in part, the bristles of a brush or the fibers of a wiping cloth (e.g., nonwoven fabric) are larger than the spaces between the microstructures. Surprisingly, some types of microstructured surfaces have been found to exhibit better microbial (e.g., bacterial) removal when cleaned compared to smooth surfaces. Such microstructured surfaces have also been found to result in reduced microbial touch transfer.

[0004] This specification describes medical diagnostic devices or components thereof comprising a microstructured surface including peaks and adjacent valleys, wherein the valleys have a maximum width in the range of 1 to 1000 microns, and the peaks have peaks. In some embodiments (for example, to improve cleanability), the peaks of the microstructured surface have sidewall angles greater than 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 degrees. The peaks may include two or more facets, such as in the case of a linear arrangement of prisms or an arrangement of cube corner elements. In some embodiments, the facets of the peaks typically form apex angles in the range of about 20 to 120 degrees. The facets form a continuous or semi-continuous surface in the same direction. The valleys typically do not have intersecting walls.

[0005] In a typical embodiment, the microstructured surface of a medical diagnostic device comes into contact with multiple patients during normal use of the device. In a typical embodiment, the medical diagnostic device includes a (e.g., acoustic) sensor, such as a stethoscope diaphragm. Surprisingly, the microstructured stethoscope diaphragm has a transfer function frequency response curve over a frequency range of 20 to 2000 Hz that is substantially equivalent to that of a similar diaphragm without a microstructured surface.

[0006] Methods for manufacturing components of acoustic medical diagnostic devices are also described, which include preparing a tool having a molded surface, wherein the molded surface is a negative replica of a microstructured surface including peaks and adjacent valleys, with the valleys having a maximum width in the range of 10 to 250 microns, and molding an epoxy resin material using the tool. In some embodiments, the molding step includes heating and compression molding a sheet of epoxy resin. [Brief explanation of the drawing]

[0007] [Figure 1] This is a perspective review of Cartesian coordinate systems for surfaces that can be used to describe various microstructured surfaces. [Figure 2] This is a cross-sectional view of a microstructured surface. [Figure 2A] It is a cross-sectional view of a microstructured surface. [Figure 3] It is a perspective view of a microstructured surface including a linear array of prisms. [Figure 4A] It is a perspective view of a microstructured surface including an array of cube corner elements. [Figure 4B] It is a perspective view of a microstructured surface including an array of pyramid-shaped elements. [Figure 4C] It is a perspective view showing the dimensions and angles of cube corner elements. [Figure 5] It is a perspective view of a microstructured surface including an array of cube corner elements of a suitable shape. [Figure 6] It is a cross-sectional view of mountain structures having various apex angles. [Figure 7] It is a cross-sectional view of a mountain structure having a rounded top. [Figure 8] It is a cross-sectional view of a mountain structure having a flat top. [Figure 9] It is a schematic view of a stethoscope. [Figure 10] It is a spare parts kit for a stethoscope. [Figure 11] It is a schematic view of various ultrasonic probes. [Figure 12] It is a schematic view of an exemplary ultrasonic probe with a cap. [Figure 13] It is a graph comparing the acoustics of a stethoscope diaphragm having a microstructured surface with a similar diaphragm having a smooth surface. [Figure 14] It is an electron micrograph of a microstructured surface of a comparative example (the scale bar represents 20 microns).

Modes for Carrying Out the Invention

[0008] Medical diagnostic articles The object of the present invention is to provide articles having surfaces with reduced contact movement and / or improved removal of microorganisms (e.g., bacteria) during cleaning, and the medical articles described herein are not typically (e.g., sterilized) medical articles such as nasogastric feeding tubes, wound contact layers, blood flow catheters, stents, pacemaker shells, heart valves, orthopedic implants (hip, knee, shoulder, etc.), periodontal implants, orthodontic brackets and other orthodontic appliances, dentures, crowns, contact lenses, intraocular lenses, soft tissue implants (breast implants, penile implants, facial and hand implants, etc.), surgical instruments, sutures (including biodegradable sutures), cochlear implants, tympanoplasty tubes, shunts (including shunts for varicella), postoperative drainage tubes and drainage devices, urethral catheters, endotracheal tubes, heart valves, wound dressings, other implantable devices, and other indwelling devices.

[0009] The medical items described can be characterized as single-use items, meaning they are discarded after a single use. The above items can also be characterized as items for a single patient. Therefore, such items are typically not cleaned (but not sterilized) and are not reused for other patients.

[0010] In contrast, the articles and surfaces described herein include those whose microstructured surfaces are exposed to the surrounding environment (e.g., indoors or outdoors) and are subject to contact with, or come into contact with, multiple people and / or animals, as well as other contaminants (e.g., dirt).

[0011] The articles described herein are non-implantable medical diagnostic devices or components thereof. As used herein, a medical diagnostic device means any device, apparatus, instrument, or machine (including components, parts, and accessories) intended for use in diagnosing a disease or other condition in a human or other animal, or in treating, alleviating, managing, or preventing a disease. Medical diagnostic devices generally do not achieve their intended purpose through chemical action within or on the surface of a human or other animal, nor do they rely on metabolism to achieve their intended purpose.

[0012] While implantable devices typically fall under the definition of medical devices (e.g., the U.S. FDA), implants are typically single-use items intended for use by a single patient. Therefore, such devices are not cleaned or reused by multiple patients. Furthermore, because implantable devices reside within the body, they are not touched or come into contact with multiple patients (humans and / or animals).

[0013] The microstructured surfaces described herein are most beneficial for medical diagnostic devices and their components that come into contact with multiple patients (i.e., humans and / or animals) during normal use of the device. Such devices and their components are typically cleaned between uses on separate patients.

[0014] In some embodiments, such as stethoscope diaphragms, the microstructured surfaces of the device or its components come into direct contact (e.g., skin) with the patient during normal use of the device. In other embodiments, such as infrared thermometers, the device may be in close proximity to the patient, even if it does not come into direct contact (e.g., skin) with the patient. However, because the device is in close proximity to the patient, such devices may be susceptible to contamination by microorganisms (e.g., bacteria) and are therefore washed between patients to prevent the spread of microorganisms to subsequent patients.

[0015] In some embodiments, the medical diagnostic device includes sensors such as optical sensors that utilize the properties of light, or acoustic sensors that utilize the properties of sound, including hearing.

[0016] One exemplary medical diagnostic device that includes acoustic components is a stethoscope, or its components such as a diaphragm. A stethoscope is used to listen to a patient's heart or breathing and typically has a small, disc-shaped resonator (i.e., a diaphragm) 13 attached to a chestpiece and placed against the chest, and two tubes connected to earpieces. The diaphragm of the stethoscope amplifies small vibrations from the patient's body and converts them into sound within the stethoscope chestpiece. The amplified sound travels through the stethoscope tubes to the earpieces, and the doctor hears the sound through the earpieces.

[0017] Referring to Figure 9, the stethoscope 10 includes a diaphragm 13 attached to a chestpiece 12. The diaphragm 13 is formed from a conventional material used in the manufacture of stethoscope chestpieces, such as epoxy resin. The chestpiece 12 having the diaphragm 13 is attached to a conventional headset, such as the one described in U.S. Patent No. 4,200,169. This headset includes an elongated flexible tube 14 that branches into a (e.g., rigid) tube 16 extending to an ear tip 18. The lower end of the flexible tube 14 is coupled to a conventional stem attachment of the chestpiece 12. The coupling can utilize an indexing lock, as taught in U.S. Patent No. 4,770,270 (the full contents of which are expressly incorporated herein by reference). The binaural tubes for stethoscopes can be prepared in accordance with the teachings of Packard et al., U.S. Patents No. 5,111,904, No. 5,380,182, and No. 5,324,471 (each incorporated herein by reference).

[0018] The ear tip 18 is determined to be of a size and shape that engages with the surface of the user's ear. The ear tip 18 may include any suitable ear tip. In one embodiment, the ear tip 18 includes a soft ear tip as disclosed in U.S. Patents No. 4,852,684, No. 4,913,259, and No. 5,449,865 (the entire contents of which are incorporated herein by reference).

[0019] In some embodiments, the chestpiece 12 is double-sided, including a first sound-collecting side and a second sound-collecting side (not shown) opposite to it, typically parallel to the first sound-collecting side. Alternatively, the diaphragm may be a single-sided diaphragm. In some embodiments, the stethoscope allows tuning of sounds while using either the first or second side of the chestpiece having a diaphragm. The first sound-collecting side is sized and shaped to collect sounds from adult patients. The second sound-collecting side is sized and shaped to provide sufficient surface contact for pediatric or slender patients. The second sound-collecting side often has a bell-shaped cavity, which is also substantially smaller than the first sound-collecting side, and is used in an open-bell configuration without a diaphragm to fit smaller patients and facilitate access to distant or hard-to-reach places. Further details regarding double-sided chestpieces are known in the art, as described in U.S. Patent No. 10,213,181, incorporated herein by reference.

[0020] Since the diaphragm comes into contact with multiple patients during normal use, it is preferable that at least the outer surface (e.g., skin contact surface) of the diaphragm includes a microstructured surface as described herein. Other components of the stethoscope, such as flexible or rigid tubes and eartips, may also optionally include a microstructured surface as described herein.

[0021] In some embodiments, the medical diagnostic device (e.g., a stethoscope) may be pre-assembled, as shown in Figure 9. In other embodiments, one or more unassembled components of the medical diagnostic device (e.g., a stethoscope) may include the microstructured surfaces described herein. For example, Figure 10 shows a (e.g., spare parts) kit for a 3M Littmann stethoscope, including an ear tip 18, a (e.g., non-chill) bell sleeve 15, a tunable single-piece diaphragm 12A for adults, and a tunable single-piece diaphragm 12B for children. Any one or any combination of such components may include the microstructured surfaces described herein.

[0022] As demonstrated by the following embodiments, it has been found that the inclusion of microstructures does not degrade the functionality of the acoustic sensor. In other words, microstructured acoustic sensors have substantially the same acoustic diagnostic characteristics as similar medical diagnostic devices or components thereof that lack microstructured surfaces.

[0023] Figure 13 is a graph comparing the acoustics of a stethoscope diaphragm with a microstructured surface (as described in more detail in the examples) to a similar diaphragm with a smooth surface. The curves coincide, demonstrating that the diaphragm with a microstructured surface has a transfer function frequency response curve over the 20–2000 Hz frequency range that is substantially equivalent to that of a similar diaphragm without a microstructured surface (e.g., a smooth surface). This graph shows that the inclusion of a microstructured surface does not impair the function of a stethoscope diaphragm for detecting pulse or heartbeat.

[0024] Another exemplary medical diagnostic device that includes acoustic components is an ultrasound device or its components, such as a probe. An ultrasound device uses a probe to transmit high-frequency (1-5 megahertz) acoustic vibration pulses into the patient's body. The acoustic waves travel through the patient's body and strike boundaries between tissues (e.g., between bodily fluids and soft tissue, or between soft tissue and bone). The reflected waves are picked up by the probe and relayed to a machine.

[0025] An ultrasonic transducer, also called a probe, generates sound waves that bounce off body tissue, creating echoes. The transducer also receives the echoes and transmits them to a computer, which uses them to create an image called a sonogram. Thus, the probe both generates and receives ultrasound. An ultrasonic probe typically comprises a beamformer, a data processor, a scan converter, and a display unit. An ultrasonic probe may include at least one transducer element that operates to convert ultrasonic signals to electrical signals. The beamformer can convert the received signal provided by the ultrasonic probe from analog to digital, delaying the time of the digital signal considering the position and focal point of each transducer element, and summing the time-delayed digital signals to form ultrasonic data, i.e., radio frequency (RF) data. The data processor performs various data processing on the ultrasonic data necessary to form an ultrasonic image. The scan converter scans the processed ultrasonic data for display as an image.

[0026] In a typical embodiment, the ultrasonic probe includes a piezoelectric device module incorporated inside its front end. The piezoelectric device is formed of a piezoelectric material. Piezoelectric ceramics such as lead zirconate titanate (PZT), which have high acoustic-electric conversion efficiency, are commonly used. The piezoelectric material can vibrate and generate pulses of sound waves that can be transmitted into the human body, and can receive reflected echoes and convert them into electrical signals.

[0027] Ultrasound diagnostic devices can receive ultrasound data from an ultrasound probe and provide high-resolution ultrasound images of a patient's internal organs. Ultrasound diagnostic devices can communicate with various electronic display devices, such as personal computers (e.g., laptops), smartphones, or tablet devices.

[0028] Figure 11 is a schematic diagram of various exemplary ultrasound probes.

[0029] Since ultrasound probes come into contact with multiple patients during normal use, it is preferable that at least the outer surface (e.g., skin contact surface) of the ultrasound probe includes a microstructured surface as described herein. Other components of the ultrasound device may also optionally include a microstructured surface as described herein.

[0030] In some embodiments, as shown in Figure 12, the ultrasonic probe 100 may further comprise a probe cap 120, such as that described in U.S. Patent Application No. 2015 / 0320402. The probe cap 120 is coupled to the front end of the probe body 110 and protects the probe body 110. In addition, the probe cap 120 can generate ultrasonic echoes while testing the piezoelectric device of the probe 110. In some embodiments, the inner and / or outer surfaces of the probe cap may include a microstructured surface, as described herein.

[0031] Other (e.g., non-implantable) medical diagnostic articles that would benefit from having a microstructured surface as described herein include, for example, various reusable medical diagnostic scopes including otoscopes (used to view the inside of the ear), ophthalmoscopes (used to view the inside of a patient's eye), esophageal stethoscopes, endoscopes, colonoscopes, etc., pulse oximeters (for monitoring changes in the oxygen saturation of a patient's blood and blood volume in the skin), (e.g., digital finger) blood pressure monitors and (e.g., reusable or disposable) blood pressure cuffs, temperature probes including electronic thermometers (for example, set in a specific part of the body to be measured, such as the forehead, mouth, armpit, rectum, or ear), sensors for monitoring moisture or sweat, and surfaces of magnetic resonance imaging (MRI), computed tomography (CT), computed axial tomography (CAT) scans, and X-ray diagnostic articles.

[0032] The microstructured surfaces described herein do not prevent the presence of microorganisms (e.g., bacteria such as Streptococcus mutans, Staphylococcus aureus, Pseudomonas aeruginosa, or φ6 bacteriophages) on the microstructured surfaces, or in other words, do not prevent the formation of biofilms. As demonstrated by the following examples, both the smooth, flat surfaces and the microstructured surfaces described herein had approximately the same amount of microorganisms (e.g., bacteria) before cleaning, i.e., more than 80 colony-forming units. Therefore, the microstructured surfaces described herein are not expected to be beneficial for sterile implantable medical devices.

[0033] However, as demonstrated by the following examples, the microstructured surfaces described herein are easier to clean, and the amount of microorganisms (e.g., bacteria) present after cleaning is small. While not intended to be theoretically bound, scanning electron microscopy images suggest that large, continuous biofilms typically form on smooth surfaces. However, even when the peaks and valleys are much larger than the microorganisms (e.g., bacteria), the microstructured surface fragments the biofilm. In some embodiments, the biofilm (before cleaning) exists not as a continuous biofilm, but as discontinuous aggregates and small groups of cells on the microstructured surface. After cleaning, biofilm aggregates in the form of small patches cover the smooth surface. However, it has been observed that the microstructured surface, after cleaning, has only small groups of cells and individual cells. In preferred embodiments, a microstructured surface may result in a log10 reduction of at least 2, 3, 4, 5, 6, 7, or 8 microorganisms (e.g., bacteria such as Streptococcus mutans, Staphylococcus aureus, Pseudomonas aeruginosa, or φ6 bacteriophages) after cleaning. In some embodiments, for highly contaminated surfaces prepared according to various test methods, a microstructured surface has an average log10 value of fewer than 6, 5, 4, or 3 recovered microbial colony-forming units after cleaning. Typical surfaces are often less contaminated initially and are therefore expected to have even fewer recovered colony-forming units after cleaning. Test methods for these properties are described in the examples.

[0034] In some embodiments, microstructured surfaces can prevent aqueous or (e.g., isopropanol) alcohol-based cleaning solutions from beading up compared to smooth surfaces of the same polymer (e.g., thermoplastic, thermosetting, or polymerized resin) material. When cleaning solutions bead up, or dewet, the disinfectant may not come into contact with microorganisms for a sufficient amount of time to kill them. However, it has been found that after 1, 2, and 3 minutes of application of the cleaning solution to the microstructured surface, at least 50, 60, 70, 80, or 90% of the microstructured surface may contain the cleaning solution (according to the test methods described in the examples).

[0035] As demonstrated by the following examples, microstructured surfaces result in a reduction of at least 25, 30, 35, 40, 45, 50, 60, 70, 80, 90, 95, or 99% of the contact migration of microorganisms (e.g., bacteria such as Streptococcus mutans, Staphylococcus aureus, Pseudomonas aeruginosa, or φ6 bacteriophages) compared to similar unstructured (e.g., smooth) surfaces. Test methods for this property are described in the examples.

[0036] In a preferred embodiment, the same microstructured surface results in both a reduction in microorganisms (e.g., bacteria) after cleaning and a reduction in microbial contact and migration.

[0037] However, in other embodiments, while microstructured surfaces may reduce the contact and movement of microorganisms, it is hypothesized that the dimensional characteristics and / or angles of the peaks and valleys may not result in a reduction of microorganisms (e.g., bacteria) after cleaning.

[0038] microstructured surface Referring to Figure 1, the microstructured surface can be characterized in three-dimensional space by superimposing a Cartesian coordinate system onto its structure. The first reference plane 124 is located at the center between the main surfaces 112 and 114. The first reference plane 124, referred to as the yz plane, has the x-axis as its normal vector. The second reference plane 126, referred to as the xy plane, extends substantially coplanar with surface 116 and has the z-axis as its normal vector. The third reference plane 128, referred to as the xz plane, is located at the center between the first end face 120 and the second end face 122 and has the y-axis as its normal vector.

[0039] In some embodiments, the article is three-dimensional at the macroscale. However, at the microscale (e.g., a surface region including at least two adjacent microstructures and valleys or channels positioned between those microstructures), the base layer / base member can be considered planar with respect to the microstructures. The width and length of the microstructures lie in the xy-plane, and the height of the microstructures lies in the z-direction. Furthermore, the base layer is parallel to the xy-plane and perpendicular to the z-plane.

[0040] Figure 2 is an exemplary cross-sectional view of a microstructured surface 200. Such a cross-section represents a plurality of individual (e.g., post or rib) microstructures 220. A microstructure includes a base portion 212 adjacent to a (e.g., machined) flat surface 216 (surface 116 in Figure 1, which is parallel to the reference plane 126). An upper (e.g., planar) surface 208 (parallel to surface 216 and the reference plane 26 in Figure 1) is spaced from the base portion 212 by the height ("H") of the microstructure. The side walls 221 of a microstructure 220 are perpendicular to the flat surface 216. When the side walls 221 are perpendicular to the flat surface 216, the microstructure has a side wall angle of 0 degrees. In the case of vertical side walls, the vertical side walls of a given ridge microstructure are parallel to each other and also parallel to adjacent microstructures that have vertical side walls. Alternatively, a microstructure 230 has angled side walls 231 that are not perpendicular to the flat surface 216. The sidewall angle 232 can be defined by the intersection of the sidewall 231 and a reference plane 233 perpendicular to the flat surface 216 (perpendicular to reference plane 126 in Figure 1 and parallel to reference plane 128). For privacy films such as those described in U.S. Patent No. 9,335,449, the wall angle is typically less than 10, 9, 8, 7, 6, or 5 degrees. Since the channels of the privacy film contain light-absorbing material, transmittance may decrease as the wall angle increases. However, as described herein, as the wall angle approaches 0 degrees, it also becomes more difficult to clean.

[0041] Described herein are microstructured surfaces including microstructures having sidewall angles greater than 10 degrees. In some embodiments, the sidewall angles are at least 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20 degrees. In other embodiments, the sidewall angles are at least 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30 degrees. For example, in some embodiments, the microstructure is a cube corner ridge structure with a sidewall angle of 30 degrees. In other embodiments, the sidewall angles are at least 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, or 45 degrees. For example, in some embodiments, the microstructure is a prism structure with a sidewall angle of 45 degrees. In other embodiments, the sidewall angles are at least 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, or 60 degrees. It is understood that even if some of the sidewalls have lower sidewall angles, the microstructured surface will still be beneficial. For example, if half of the arrangement of ridge structures has sidewall angles within the desired range, about half of the improved microbial (e.g., bacterial) removal benefits may be obtained. Thus, in some embodiments, less than 50, 45, 40, 35, 30, 25, 20, 15, 10, 5, or 1% of the ridge structures have sidewall angles of less than 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 degree. In some embodiments, less than 50, 45, 40, 35, 30, 25, 20, 15, 10, 5, or 1% of the ridge structure has a sidewall angle of less than 30, 25, 20, or 15 degrees. In some embodiments, less than 50, 45, 40, 35, 30, 25, 20, 15, 10, 5, or 1% of the ridge structure has a sidewall angle of less than 40, 35, or 30 degrees. Alternatively, as described above, at least 50, 60, 70, 80, 90, 95, or 99% of the ridge structure has a sufficiently large sidewall angle.

[0042] For example, as described in International Publication No. 2013 / 003373, microstructures with cross-sectional dimensions of 5 microns or less are considered to substantially hinder the colonization and attachment of target bacteria that are most involved in HAI, or other biofouling problems such as increased drag, reduced heat transfer, and filtration fouling. Referring to Figure 2, the cross-sectional width of the microstructure shown in this figure ("W") M The cross-sectional width of the channel or valley between adjacent microstructures ("W") V The cross-sectional width (W) of the microstructure is less than or equal to the given value. Therefore, as shown in this embodiment of the linear prism, the cross-sectional width (W) of the microstructure is less than or equal to the given value. M If the cross-sectional width (W) of the channel or valley between the microstructure is 5 microns or less, V ) is also 5 microns or less. As shown by the microstructure 220 in Figure 2, when the side wall angle of the microstructures on both sides of the valley is 0, the channel or valley defined by the side wall is the same width (W) as the one adjacent to the bottom surface 212. V ) has adjacent to the top surface 208. If the side wall angle of the microstructure is greater than 0, as shown by line 231 of the microstructure 230, the valley typically has a larger (e.g., maximum) width adjacent to the top surface 208 compared to the width of the channel or valley adjacent to the bottom surface 212.

[0043] It has been found that when the sidewall angle is too small, and / or the maximum width of the valleys is too small, and / or the microstructured surface contains an excessive amount of flat surface area, the microstructured surface becomes more difficult to clean (e.g., of bacteria and dirt).

[0044] Described herein are microstructured surfaces containing microstructures with a maximum valley width of at least 1, 2, 3, or 4 microns, typically greater than 5, 6, 7, 8, 9, or 10 microns, and up to 250 microns. In some embodiments, the maximum valley width is at least 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, or 25 microns. In some embodiments, the maximum valley width is at least 30, 35, 40, 45, or 50 microns. In some embodiments, the maximum valley width is greater than 50 microns. In some embodiments, the maximum valley width is at least 55, 60, 65, 70, 75, 85, 85, 90, 95, or 100 microns. In some embodiments, the maximum valley width is at least 125, 150, 175, 200, 225, or 250 microns. The wider the valleys, the more suitable it may be for removing dirt. In some embodiments, the maximum valley width is 1000, 950, 900, 850, 800, 750, 700, 650, 600, 550, 500, 450, 400, 350, 300, 250, 225, 200, 175, 150, 125, 100, 75, or 50 microns or less. In some embodiments, the maximum valley width is 45, 40, 35, 30, 25, 20, or 15 microns or less. It is understood that even if some of the valleys are smaller than the maximum width, a microstructured surface will still be beneficial. For example, if half of the total number of valleys on a microstructured surface are within the desired range, approximately half the benefit may be obtained. Therefore, in some embodiments, less than 50, 45, 40, 35, 30, 25, 20, 15, 10, 5, or 1% of the valleys have a maximum width of less than 10, 9, 8, 7, 6, or 5 microns. Alternatively, as described above, at least 50, 60, 70, 80, 90, 95, or 99% of the valleys have a maximum width.

[0045] In a typical embodiment, the maximum width of the microstructure is within the same range as described for the valleys. In other embodiments, the width of the valleys may be greater than the width of the microstructure. Thus, in some preferred embodiments, the microstructured surface is substantially free of microstructures having widths of 5, 4, 3, 2, or less than 1 micron, and typically includes nanostructures having a width of less than 1 micron. Some examples of microstructured surfaces further including nanostructures are described in International Publication No. 2012 / 058605 cited above. The nanostructure typically includes at least one or two dimensions (e.g., width and height) not exceeding 1 micron, and typically includes one or two dimensions less than 1 micron. In some embodiments, all dimensions of the nanostructure are not exceeding 1 micron or are less than 1 micron.

[0046] Substantially absent means that such microstructures are either completely absent or several may be present, provided that their presence does not impair the properties (e.g., cleanability) as described later. Thus, the microstructured surface or its microstructures may further include nanostructures, provided that the microstructured surface provides the technical effects described herein.

[0047] A microstructured surface may be located on a second microstructured surface, provided that the surface provides the technical effects described herein. The second microstructured surface typically has a larger microstructure (e.g., a larger valley width and / or height).

[0048] A microstructured surface may be present on a macrostructured surface, provided that the surface provides the technical effects described herein. A macrostructured surface is typically visible without magnification by a microscope. A macrostructured surface has at least two dimensions (e.g., length and width) of at least 1 mm. In some embodiments, the average width of the macrostructure is at least 2, 3, 4, 5, 6, 7, 8, 9, or 10 mm. In some embodiments, the average length of the macrostructure may be in the same range as the average width, or may be significantly greater than the width. For example, if the macrostructure is a wood-grain microstructure, such as those often found on doors, the length of the macrostructure may extend along the entire length of the article (e.g., a door). The height of a macrostructure is typically less than its width. In some embodiments, the height is less than 5, 4, 3, 2, 1, or 0.5 mm.

[0049] Smaller structures, including nanostructures, can prevent biofilm formation, but the presence of numerous small valleys and / or valleys with insufficient sidewall angles can hinder cleanability, including the removal of dirt. Furthermore, microstructured surfaces with larger microstructures and valleys can typically be manufactured at a faster rate. Thus, in typical embodiments, the dimensions of the microstructures are at least 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, or 15 microns, or greater than 15 microns as described above. Furthermore, in some preferred embodiments, the dimensions of at least 50, 60, 70, 80, 90, 95, or 99% of the microstructures are not less than 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 micron.

[0050] Figure 14 shows a microstructured surface of a comparative example having discontinuous valleys. Such surfaces are also described as having groups of feature regions arranged relative to one another to define meandering paths. Rather, the valleys are divided by walls, forming an array of individual cells, each cell surrounded by a wall. Some of the cells are about 3 microns long, while others are about 11 microns long. In contrast, the valleys of the described microstructured surfaces substantially do not contain intersecting sidewalls or other obstructions to the valleys. Substantially not containing means that sidewalls or other obstructions are either not present in the valleys, or some may be present, provided that their presence does not impair the cleaning properties, as will be described later. The valleys are typically continuous in at least one direction. This allows for a smooth flow of the cleaning solution through the valleys. Thus, the arrangement of peaks typically does not define meandering paths.

[0051] As described above, the height of the peaks is within the same range as the maximum width of the valleys. In some embodiments, the peak structure typically has a height (H) in the range of 1 to 125 microns. In some embodiments, the height of the microstructure is at least 2, 3, 4, or 5 microns. In some embodiments, the height of the microstructure is at least 6, 7, 8, 9, or 10 microns. In some embodiments, the height of the microstructure is 100, 90, 80, 70, 60, or 50 microns or less. In some embodiments, the height of the microstructure is 45, 40, 35, 30, or 25 microns or less. In some embodiments, the height of the microstructure is 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, or 10 microns or less. In a typical embodiment, the height of the valleys or channels is within the same range as described for the peak structure. In some embodiments, the peak structure and the valleys have the same height. In other embodiments, the height of the peak structure may vary. For example, a microstructured surface may be placed on a macrostructured surface or a microstructured surface, rather than on a planar surface.

[0052] The aspect ratio of the valley is obtained by dividing the valley height (which can be the same as the peak height of the microstructure) by the maximum width of the valley. In some embodiments, the aspect ratio of the valley is at least 0.1, 0.15, 0.2, or 0.25. In some embodiments, the aspect ratio of the valley is 1, 0.9, 0.8, 0.7, 0.6, or 0.5 or less. Thus, in some embodiments, the valley height is typically less than or equal to the maximum width of the valley, and more typically less than the maximum width of the valley.

[0053] The base of each microstructure may include, but is not limited to, a variety of cross-sectional shapes, including, optionally, parallelograms with rounded corners, rectangles, squares, circles, semicircles, semi-ellipses, triangles, trapezoids, and other polygons (e.g., pentagons, hexagons, octagons, etc., and combinations thereof).

[0054] In one embodiment, the microstructured surface may have the same surface as the brightness-enhancing film. For example, as described in U.S. Patent No. 7,074,463, a backlit liquid crystal display generally includes a brightness-enhancing film placed between a diffuser and the liquid crystal display panel. The brightness-enhancing film collimates light, thereby increasing the brightness of the liquid crystal display panel and reducing the power of the light source. Therefore, brightness-enhancing films are used as internal components of illuminated display devices (e.g., mobile phones, computers) that are not exposed to microorganisms (e.g., bacteria) or contaminants.

[0055] Referring to Figure 3, in one embodiment, the microstructured surface 300 includes a linear arrangement of regular right-angle prisms 320. Each prism has a first facet 321 and a second facet 322. The prisms are typically formed on a base member 310 (e.g., a pre-formed polymer film), which has a first flat surface 331 (parallel to the reference plane 126) on which the prisms are formed, and a second surface 332 that is substantially flat or planar and opposite to the first surface. Right-angle prisms mean that the apex angle θ340 is typically about 90°. However, this angle can be in the range of 70° to 120°, and may be in the range of 80° to 100°. In some embodiments, the apex angle may be greater than 60, 65, 70, 75, 80, or 85°. In some embodiments, the vertex angles may be less than 150, 145, 140, 135, 130, 125, 120, 110, or 100°. These vertices may be sharp (as shown), rounded (as shown in Figure 7), or truncated (as shown in Figure 8). In some embodiments, the angle of the valleys is within the same range as the vertex angles. The spacing between peaks (e.g., in a prism) may be characterized as the pitch ("P"). In this embodiment, the pitch is also equal to the maximum width of the valleys. Thus, the pitch is greater than 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 microns, as previously stated, and up to a maximum of 250 microns. The length ("L") of the microstructure (e.g., in a prism) is typically the maximum dimension and may extend over the entire dimension of the microstructured surface, film, or article. The prism facets do not need to be identical, and the prisms may be tilted relative to each other, as shown in Figure 6.

[0056] In another embodiment, the microstructured surface may have the same surface as the cube corner retroreflective sheet. Retroreflective materials are characterized by their ability to redirect light incident on the material back to the source. This property has led to the widespread use of retroreflective sheets for a variety of traffic safety and personal safety applications. Referring to Figure 4A, the cube corner retroreflective sheet typically comprises a thin transparent layer having a substantially planar front and a rear structured surface 10 containing a plurality of cube corner elements 17. A sealing film (not shown) is typically applied to the back of the cube corner elements. See, for example, U.S. Patents 4,025,159 and 5,117,304. The sealing film maintains an air interface on the back of the cube, enabling internal total reflection at the interface and preventing the intrusion of contaminants such as dirt and / or moisture.

[0057] The microstructured surface 10 in Figure 4A can be characterized as an array of cube corner elements 17 defined by three sets of parallel grooves (i.e., valleys) 11, 12, and 13. Two sets of grooves (i.e., valleys) intersect each other at angles greater than 60 degrees, and a third set of grooves (valleys) intersects each of the other two sets at angles less than 60 degrees, forming an array of inclined cube corner element corresponding pairs (see U.S. Patent No. 4,588,258 (Hoopman)). The groove angles are selected to be dihedral angles formed in the straight sections of the groove intersections, for example, 14, 15, and 16 for a typical cube corner element 17 are approximately 90 degrees.

[0058] In some embodiments, the base of the triangle has an angle of at least 64, 65, 66, 67, 68, 69, or 70 degrees, and the other angles are 55, 56, 57, or 58 degrees.

[0059] In another embodiment shown in Figure 4B, the microstructured surface 400 of Figure 4B may feature an array of pyramidal ridge structures 420 defined by a first set of parallel grooves (i.e., valleys) in the y-direction and a second set of parallel grooves in the x-direction. The base of the pyramidal ridge structure is polygonal, typically square or rectangular, depending on the spacing of the grooves. The apex angle θ440 is typically about 90°. However, this angle is typically in the range of 70° to 120° and may be in the range of 80° to 100°. In other embodiments, the apex angle is at least 20°, 30°, 40°, 50°, or 60°.

[0060] Other cube corner element structures described as “full cube” or “preferred shape (PG) cube corner element” typically include at least two non-biplane edges that are not coplanar, as described in U.S. Patent No. 7,188,960, which is incorporated herein by reference. A full cube is not truncated. In one embodiment, the base portion of a full cube element in a plan view is not triangular. In another embodiment, the non-biplane edges of a full cube element are not all in the same plane (i.e., not coplanar). Such cube corner elements may be characterized as “preferred shape (PG) cube corner elements.”

[0061] A PG cube corner element can be defined in the context of a structured surface of a cube corner element extending along a reference plane. A PG cube corner element means a cube corner element having at least one non-double edge that is (1) non-parallel to the reference plane and (2) substantially parallel to the adjacent non-double edge of a neighboring cube corner element. Cube corner elements with reflective surfaces, including rectangular (including square), trapezoidal, or pentagonal shapes, are examples of PG cube corner elements.

[0062] Referring to Figure 5, in another embodiment, the microstructured surface 500 may include an array of preferred shape (PG) cube corner elements. An exemplary microstructured surface includes four rows (501, 502, 503, and 504) of preferred shape (PG) cube corner elements. Each row of preferred shape (PG) cube corner elements has a face formed from a pair of first and second grooves, also called “gutters.” Such gutters are nominally parallel to adjacent gutters, but non-parallel by nominally ~ 1 degree. Such gutters are typically perpendicular to the reference plane 124 in Figure 1. A third face of such a cube corner element preferably comprises a main groove face 550. This main groove face range is nominally perpendicular to the face formed from the gutter, but non-perpendicular by nominally ~ 1 degree. In some embodiments, the gutters can form a nominal apex angle θ of 90 degrees. In other embodiments, a row of preferred shape (PG) cube corner elements includes a ridge structure formed from alternating pairs of side grooves 510 and 511 (e.g., about 75 degrees and about 105 degrees), as shown in Figure 5. Thus, the apex angles 540 of adjacent (PG) cube corner elements may be greater than or less than 90 degrees. In some embodiments, the average apex angles of adjacent (PG) cube corner elements in the same row are typically 90 degrees. As described in U.S. Patent No. 7,188,960 cited above, during the manufacture of a microstructured surface containing PG cube corner elements, the side grooves can be formed independently on individual thin layers (thin plates), each thin layer having one row of such cube corner elements. Pairs of thin layers having opposite orientations are arranged such that their respective main groove faces form main grooves 552, thereby minimizing the formation of vertical walls. The thin layers can be assembled to form a microstructured surface, and then replicated to form a tool of appropriate size.

[0063] In some embodiments, all peak structures have the same apex angle θ. For example, the aforementioned microstructured surface in Figure 3 shows multiple prism structures, each having an apex angle θ of 90 degrees. As another example, the aforementioned microstructured surface in Figure 4B shows multiple pyramidal structures, each having an apex angle θ of 60 degrees. In other embodiments, peak structures may form apex angles that are not the same. For example, as shown in Figure 5, some of the peak structures may have apex angles greater than 90 degrees, and some of the peak structures may have apex angles less than 90 degrees. In some embodiments, the peak structures of an array of microstructures have peak structures with different apex angles, but the apex angles average in the range of 60 to 120 degrees. In some embodiments, the average apex angle is at least 65, 70, 75, 80, or 85 degrees. In some embodiments, the average apex angle is less than 115, 110, 100, or 95 degrees.

[0064] As yet another example, as shown in the cross section of Figure 6, the microstructured surface 600 may include multiple crest structures such as 646, 648, and 650, each having crests 652, 654, and 656. If the microstructured surface does not include a flat surface (i.e., a surface parallel to the reference plane 126 in Figure 1), the facets of adjacent crest structures may also define valleys between adjacent crests. In some embodiments, the facets of a crest structure form valleys with valley angles of less than 90 degrees (e.g., valley 658). In some embodiments, the facets of a crest structure form valleys with valley angles greater than 90 degrees (e.g., valley 660). In some embodiments, the valleys are symmetrical, as shown by valleys 658 and 660. In other embodiments, the valleys are symmetrical, as shown by valley 662. When the valleys are symmetrical, the sidewalls of adjacent crest structures defining the valleys are substantially identical. When a valley is asymmetrical, the side walls of the adjacent peak structures defining the valley are different. A microstructured surface can have a combination of symmetrical and asymmetrical valleys.

[0065] Figure 7 shows another embodiment of the microstructured surface 700, where the peak structure has rounded peaks 740. These peak structures are characterized by a chord width 742, a cross-sectional base peak width 744, a radius of curvature 746, and a root angle 748. In some embodiments, the chord width is equal to about 20% to 40% of the cross-sectional pitch width. In some embodiments, the radius of curvature is equal to about 20% to 50% of the cross-sectional pitch width. In some embodiments, the root angle is at least 50, 65, 70, 80, or 85 degrees. In some embodiments, the root angle is 110, 105, 100, or 95 degrees or less. In some embodiments, a root angle of at least 60, 65, 70, 75, 80, or 90 degrees is preferred. The root angle may be the same as the valley angle. In some embodiments, the peak structure has a peak that is at least 2, 3, or 4 micrometers in size and rounded to a radius of 15, 10, or 5 micrometers or less. In some embodiments, the valley is at least 2, 3, or 4 micrometers in size and rounded to a radius of 15, 10, or 5 micrometers or less. In some embodiments, both the peak and the valley are at least 2, 3, or 4 micrometers in size and rounded to a radius of 15, 10, or 5 micrometers or less.

[0066] Figure 8 shows another embodiment of the microstructured surface 800, where the ridge structure 840 has a truncated, flat, or in other words, planar, top surface (substantially parallel to the reference plane 126 in Figure 1). These ridge structures can be characterized by a flattened width 842 and a cross-sectional base ridge width 844. In a typical embodiment, the flattened width may be 50, 45, 40, 35, 30, 25, 20, 15, 10, 5, 4, 3, 2, or 1% or less of the cross-sectional base ridge width. In particular, the ridge structures can have the same sidewall angle regardless of whether the ridge is sharp, rounded, or truncated.

[0067] In some embodiments, the ridge structure typically includes at least two (e.g., the prism in Figure 3), three (e.g., the cube corner in Figure 4A), or more facets. For example, if the base of the microstructure is octagonal, the ridge structure includes eight sidewall facets. However, if the facets have rounded or truncated surfaces, as shown in Figures 7 and 8, the microstructure may not be characterized by a particular geometric shape.

[0068] When the facets of a microstructure are joined such that the peaks and valleys are sharp or rounded but not truncated, the microstructured surface may be characterized by not including any flat surfaces parallel to the planar base layer. However, when the peaks and / or valleys are truncated, the microstructured surface typically has flat surface areas of less than 50, 45, 40, 35, 30, 25, 20, 15, 10, 5, or 1%, and these flat surface areas are substantially parallel to the planar base layer. In one embodiment, the valleys may have flat surfaces, and only one of the side walls of the peaks is angled as shown in Figure 2A. However, in a preferred embodiment, both side walls of adjacent peaks defining a valley are angled toward each other as described above. Thus, the side walls on both sides of the valley are not parallel to each other.

[0069] In the embodiments shown in Figures 3 to 8, adjacent facets of a peak structure (e.g., prism or cube corner) are typically connected at the bottom of the valley, i.e., near the planar base layer. The facets of the peak structure form a continuous surface in the same direction. For example, in Figure 3, facets 321 and 322 of the (e.g., prism) peak structure are continuous in the direction of the length (L) of the microstructure, or in other words, in the y-direction. As yet another example, the main grooves 452 and 550 of the PG cube corner element in Figure 5 form a continuous surface in the y-direction. In other embodiments, the facets form a semi-continuous surface in the same direction. For example, in Figure 4, the facets of the (e.g., cube corner or pyramidal) peak structure are in the same plane in both the x and y directions. These semi-continuous and continuous surfaces can facilitate the washing of pathogens from the surface.

[0070] In some embodiments, the apex angle of a crest structure is typically twice the wall angle, especially when the facets of the crest structure are interconnected in the valleys between the crests. Thus, the apex angle is typically greater than 20 degrees, and more typically at least 25, 30, 35, 40, 45, 50, 55, or 60 degrees. The apex angle of a crest structure is typically less than 160 degrees, and more typically less than 155, 150, 145, 140, 135, 130, 125, or 120 degrees.

[0071] A topographic map was obtained using a confocal laser scanning microscope (CLSM). The CLSM instrument used for all imaging was a Keyence VK-X200. CLSM is an optical microscopy technique that uses a focused laser beam to scan a surface and map its topography. CLSM works by passing a laser beam through the aperture of the light source and then focusing it onto a small area on the surface using an objective lens, and building an image pixel by pixel by collecting photons emitted from the sample. This is done by blocking out-of-focus light during image formation using a pinhole. Various parameters were measured using SPIP 6.7.7 image measurement software, following the manual (see https: / / www.imagemet.com / media-library / support-documents) with dimensional analysis.

[0072] Surface roughness parameters, Sa (average roughness), Sq (root mean square), and Sbi (surface bearing index) and Svi (fluid retention index in valleys) were calculated from topographic images (3D). Before calculating the roughness, a "subtraction plane" (removal of the first-order plane fitting form) was performed using plane correction.

[0073] The following table describes the S-parameters for several representative examples and comparative examples. [Table 1]

[0074] The average roughness Sa is defined as follows:

number

[0075] While Sa may approach zero on smooth surfaces, the smooth surfaces of comparative examples found to have insufficient microbial removal after washing had an average surface roughness Sa of at least 10, 15, 20, 25, or 30 nm. The average surface roughness Sa of the smooth surfaces of the comparative examples was less than 1000 nm (1 micron). In some embodiments, the Sa of the smooth surfaces of the comparative examples was at least 50, 75, 100, 125, 150, 200, 250, 300, or 350 nm. In some embodiments, the Sa of the smooth surfaces of the comparative examples was 900, 800, 700, 600, 500, or 400 nm or less.

[0076] The average surface roughness Sa of the microstructured surface with improved microbial removal after washing was 1 micron (1000 nm) or greater. In some embodiments, Sa was at least 1100 nm, 1200 nm, 1300 nm, 1400 nm, 1500 nm, 1600 nm, 1700 nm, 1800 nm, 1900 nm, or 2000 nm (2 microns). In some embodiments, Sa of the microstructured surface was at least 2500 nm, 3000 nm, 3500 nm, 4000 nm, or 5000 nm. In some embodiments, Sa of the microstructured surface was at least 10,000 nm, 15,000 nm, 20,000 nm, or 25,000 nm. In some embodiments, the Sa of the microstructured surface with improved microbial removal after washing was 40,000 nm (40 microns), 35,000 nm, 30,000 nm, 15,000 nm, 10,000 nm, or 5,000 nm or less.

[0077] In some embodiments, the Sa of the microstructured surface is at least 2 or 3 times that of the smooth surface. In other embodiments, the Sa of the microstructured surface is at least 4, 5, 6, 7, 8, 9, or 10 times that of the smooth surface. In other embodiments, the Sa of the microstructured surface is at least 15, 20, 25, 30, 35, 40, 45, or 50 times that of the smooth surface. In other embodiments, the Sa of the microstructured surface is at least 100, 200, 300, 400, 500, 600, 700, 800, 900, or 1000 times that of the smooth surface.

[0078] Root Mean Square (RMS) parameter S q It is defined as follows:

number

[0079] The Sq value is slightly higher than the Sa value, but the Sq value is also within the same range as the Sa value.

[0080] The surface bearing index Sbi is defined as follows:

number

[0081] Valley fluid retention index S vi It is defined as follows:

number

[0082] As shown in the S-parameter table above, the Sbi / Svi ratios of the smooth samples in the comparative examples were 1 and 3. The microstructured surfaces with improved microbial removal after washing had an Sbi / Svi ratio greater than 3. The microstructured surfaces had an Sbi / Svi ratio of at least 4, 5, or 6. In some embodiments, the microstructured surfaces with improved microbial removal after washing had an Sbi / Svi ratio of at least 7, 8, 9, or 10. In some embodiments, the microstructured surfaces with improved microbial removal after washing had an Sbi / Svi ratio of at least 15, 20, 25, 30, 35, 40, or 45. The microstructured surfaces with improved microbial removal after washing had a smaller Sbi / Svi ratio than the square corrugated microstructured surfaces in the comparative examples. Therefore, the microstructured surfaces with improved microbial removal after washing had an Sbi / Svi ratio of 90, 85, 80, 75, 70, or less than 65. In some embodiments, microstructured surfaces with improved microbial removal after washing had Sbi / Svi ratios of 60, 55, 50, 45, 40, 35, 30, 25, 20, or less than 10.

[0083] Topographic maps can also be used to measure other features of the microstructured surface. For example, peak height (especially repeating peaks of the same height) can be determined from the software's height histogram function. To calculate the percentage of "flat areas" in a rectangular corrugated film, the SPIP particle pore analysis function can be used to identify the "flat areas," which in this case is the "flat peaks" of the microstructured rectangular corrugated film.

[0084] method Microstructured surfaces can be formed by a variety of high-resolution methods, including but not limited to coating, casting and curing, injection molding, and / or compression techniques of polymerizable resins. For example, microstructuring of a surface (e.g., processed) can be achieved by at least one of the following: (1) casting a molten thermoplastic resin using a tool having a microstructured pattern; (2) coating a fluid onto a tool having a microstructured pattern, allowing the fluid to solidify, and removing the resulting film; (3) passing the thermoplastic film through a nip roll and pressing it against the tool having a microstructured pattern to compress it (i.e., embossing); and / or (4) bringing a solution or dispersion of a polymer in a volatile solvent into contact with the tool having a microstructured pattern, and removing the solvent by evaporation, for example. The tool can be formed using any of a number of techniques known to those skilled in the art, selected to some extent depending on the tool material and the desired topographic characteristics. Illustrative techniques include etching (e.g., chemical etching, mechanical etching, or other ablation methods such as laser ablation or reactive ion etching, and combinations thereof), photolithography, stereolithography, micromachining, knurling (e.g., cutting knurling or acid-strengthened knurling), scoring, cutting, or combinations thereof. In some embodiments, the tool is a metal tool. The tool may further include a diamond-like glass layer, as described in International Publication No. 2009 / 032815 (David).

[0085] Alternative methods for forming microstructured surfaces (e.g., processing) include extrusion of thermoplastic resins, curable fluid coating, and embossing of curable thermoplastic layers. Additional information on materials and various processes for forming microstructured surfaces (e.g., processing) can be found, for example, in Halverson et al.'s International Publication 2007 / 070310 and U.S. Patent Application Publication 2007 / 0134784, Hanschen et al.'s U.S. Patent Application Publication 2003 / 0235677, Graham et al.'s International Publication 2004 / 000569, Ylitalo et al.'s U.S. Patent No. 6,386,699, Johnston et al.'s U.S. Patent Application Publication 2002 / 0128578 and U.S. Patents No. 6,420,622, 6,867,342, and 7,223,364, and Scholz et al.'s U.S. Patent No. 7,309,519.

[0086] In some embodiments, the microstructured surface is incorporated into at least a portion of the surface of a medical diagnostic device or its components. In these embodiments, the microstructured surface is typically formed during the manufacture of the medical diagnostic device or its components. In some embodiments, this is achieved by molding a resin (e.g., thermoplastic, thermosetting, or polymerizable), compression molding a sheet (e.g., thermosetting or thermoplastic), or thermoforming a microstructured sheet.

[0087] In one embodiment, components of a medical diagnostic device (e.g., a diaphragm of a stethoscope) can be prepared by casting a liquid (e.g., thermoplastic, thermosetting, or polymerizable) resin into a mold, and the molded surface includes a negative mold replica of a microstructured surface.

[0088] epoxy resin composition Epoxy resin compositions generally comprise at least one epoxy resin containing at least two epoxide groups. An epoxide group is a cyclic ether having three ring atoms, and is sometimes called a glycidyl group or oxirane group. Epoxy resins are typically low molecular weight monomers that are liquid at ambient temperature.

[0089] The epoxy resin composition generally comprises at least one epoxy resin including at least one cyclic portion. The cyclic portion may be aromatic or cyclic aliphatic.

[0090] In some embodiments, the epoxy resin composition includes a bisphenol epoxy resin. The bisphenol epoxy resin is formed by reacting epichlorohydrin with bisphenol A to form a diglycidyl ether of bisphenol A.

[0091] Examples of commercially available bisphenol epoxy resins include diglycidyl ethers of bisphenol A (e.g., available from Momentive Specialty Chemicals, Inc. under trade names EPON 828, EPON 1001, EPON 1004, EPON 2004, EPON 1510, and EPON 1310, and available from Dow Chemical Co. under trade names DER331, DER332, DER334, and DEN439); diglycidyl ethers of bisphenol F (e.g., available from Huntsman Corporation under trade name ARALDITE GY 281) or blends of bisphenol A and F resins such as EPIKOTE 232 from Momentive Specialty Chemicals, Inc.; and flame-retardant epoxy resins (e.g., available under trade name DER 560, and brominated bisphenol epoxy resins available from Dow Chemical Company).

[0092] Aromatic epoxy resins can also be prepared by the reaction of aromatic alcohols such as biphenyldiols, triphenyldiols, and triols with epichlorohydrins. Such aromatic biphenyl epoxy resins and aromatic triphenyl epoxy resins are not bisphenol epoxy resins. One representative compound is the tris-(hydroxyphenyl)methane epoxy available from Huntsman Corporation (Basel, Switzerland) as Tactix® 742.

[0093] Novolac epoxy resins are formed by the reaction of phenol and formaldehyde, followed by glycidylation with epichlorohydrin to produce epoxidized novolacs such as epoxyphenol novolac (EPN) and epoxy cresol novolac (ECN). These are very viscous relative to solid resins and have a typical average epoxide functional value of approximately 2 to 6. A representative commercially available novolac epoxy resin is the antisolid epoxy novolac resin sold by Dow under the trade name "DEN431". Such novolac epoxy resins can be used in combination with epoxy resins that are liquid at 25°C.

[0094] In some embodiments, the epoxy resin is an alicyclic epoxy resin containing two or more 1,2-epoxy groups per molecule. These are generally prepared by epoxidizing unsaturated aromatic hydrocarbon compounds such as cycloolefins using hydrogen peroxide or peracids such as peracetic acid and perbenzoic acid, as is known in the art. Such alicyclic epoxy resins have a saturated (i.e., non-aromatic) ring structure, and the epoxide groups are either part of the ring or bonded to the ring structure. These epoxy resins typically contain one or more ester bonds between the epoxide groups. Alkylene (C1-C4) bonds are also typically present between the epoxide groups and ester bonds, or between the ester bonds. An exemplary alicyclic epoxy resin is, for example, 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate bis(3,4-epoxycyclohexylmethyl)adipate. Other suitable alicyclic epoxy resins include vinylcyclohexane dioxide containing two epoxide groups (one of which is part of the ring structure); 3,4-epoxy-6-methylcyclohexylmethyl-3,4-epoxycyclohexanecarboxylate; and dicyclopentadiene dioxide. Other suitable alicyclic epoxy resins containing glycidyl ethers include 1,2-bis(2,3-epoxycyclopentyloxy)-ethane; 2,3-epoxycyclopentylglycidyl ether; diglycidylcyclohexane-1,2-dicarboxylate; 3,4-epoxycyclohexylglycidyl ether; bis-(2,3-epoxycyclopentyl) ether; bis-(3,4-epoxycyclohexyl) ether; 5(6)-glycidyl-2-(1,2-epoxyethyl)bicyclo[2.2.1]heptane; cyclohexa-1,3-diene dioxide; and 3,4-epoxy-6-methylcyclohexylmethyl3',4'-epoxy-6'-methylcyclohexanecarboxylate.

[0095] Furthermore, epoxy resins in which 1,2-epoxy groups are bonded to various heteroatoms or functional groups are also preferred. Examples of such compounds include N,N,O-triglycidyl derivatives of 4-aminophenol, N,N,O-triglycidyl derivatives of 3-aminophenol, glycidyl ether / glycidyl esters of salicylic acid, N-glycicyl-N'-(2-glycidyloxypropyl)-5,5-dimethylhydantoin, or 2-glycidyloxy-1,3-bis-(5,5-dimethyl-1-glycidylhydantoin-3-yl)propane.

[0096] Epoxy resins typically have an epoxy equivalent of 50 to 250, 300, 350, 400, 450, or 500 grams per epoxide group. Epoxy resins typically have a viscosity of less than about 1000 cps at 25°C. In some embodiments, the viscosity is at least 50, 100, 150, 200, 250, or 300 centipoise. In some embodiments, the viscosity is 900, 800, 700, 600, or 500 centipoise or less. A single epoxy resin or a combination of epoxy resins may be used. Epoxy resin compositions typically contain at least 5, 6, 7, 8, 9, or 10% by weight of epoxy resin, based on the weight of the total epoxy resin composition. Due to high concentrations of thermally conductive inorganic particles, the amount of epoxy resin is typically 20% by weight or less, and in some embodiments, 19, 18, 17, 16, or 15% by weight or less.

[0097] In some embodiments, the epoxy resin composition further comprises oligomer or polymer components. The oligomer or polymer components can impart flexibility, thermal shock resistance, crack resistance, and impact resistance to the cured epoxy resin composition.

[0098] In some embodiments, oligomer or polymer components can be characterized as reinforcing agents. Reinforcing agents are typically organic polymer additives that undergo phase separation in the cured epoxy resin. Reinforcing agents can be characterized as non-reactive oligomer or polymer components. Examples of reinforcing agents include block copolymers, amphiphilic block copolymers, acrylic block copolymers, carboxyl-terminated butadiene acrylonitrile rubber (CTBN), core-shell rubber (CSR), linear polybutadiene-polyacrylonitrile copolymers, oligomeric polysiloxanes, silicone polyethers, organopolysiloxane resins, or mixtures thereof. Other epoxy-reactive polymer reinforcing agents include carboxyl-terminated polybutadienes, polysulfide-based reinforcing agents, amine-terminated butadiene nitrile rubbers, polythioethers, or mixtures thereof.

[0099] Examples of epoxy-reactive oligomer components include, for example, fatty acids; fatty acid anhydrides such as polyazelaic anhydride and dodecenyl succinic anhydride; diols such as ethylene glycol; polyols; polyether diols such as polymers of ethylene glycol, polyethylene glycol, and polypropylene glycol; aliphatic alcohols; and other materials having hydroxyl groups, carboxyl epoxy, and / or carboxylic acid anhydride functional groups. Other suitable oligomer components include trivalent and divalent carboxyl-terminated, carboxylic acid anhydride-terminated, glycidyl-terminated, and hydroxyl-terminated polyethylene glycol, polypropylene glycol, or polybutylene glycol.

[0100] In some embodiments, the epoxy resin composition includes a curing agent. Common curing agents for epoxy resins include amines, amides, ureas, imidazoles, and thiols. Curing agents typically exhibit high reactivity with epoxide groups at ambient temperatures.

[0101] In some embodiments, the curing agent contains a reactive -NH group or a reactive -NR1R2 group, where R1 and R2 are independently H or C1 - C4 alkyl, and most typically are H or methyl.

[0102] One class of curing agents are primary, secondary, and tertiary polyamines. The polyamine curing agent may be linear, branched, or cyclic. In some preferred embodiments, the polyamine cross - linker is aliphatic. Alternatively, aromatic polyamines can be utilized.

[0103] Useful polyamines are polyamines of the general formula R5-(NR1R2) x wherein R1 and R2 are independently H or alkyl, R5 is a polyvalent alkylene or arylene, and x is at least 2. The alkyl groups of R1 and R2 are typically C1 - C 18 alkyl, more typically C1 - C4 alkyl, and most typically methyl. R1 and R2 can be combined to form a cyclic amine. In some embodiments, x is 2 (i.e., diamine). In other embodiments, x is 3 (i.e., triamine). In still other embodiments, x is 4.

[0104] Useful diamines are of the general formula: [Chemical formula] [wherein R1, R2, R3, and R4 are independently H or alkyl, and R5 is a divalent alkylene or arylene]. In some embodiments, R1, R2, R3, and R4 are each H, and the diamine is a primary amine. In other embodiments, R1 and R4 are each H, R2 and R4 are each independently alkyl, and the diamine is a secondary amine. In still other embodiments, R1, R2, R3, and R4 are independently alkyl, and the diamine is a tertiary amine.

[0105] In some embodiments, primary amines are preferred. Examples include hexamethylenediamine; 1,10-diaminodecane; 1,12-diaminododecane; 2-(4-aminophenyl)ethylamine; isophoronediamine; norbornanediamine 4,4'-diaminodicyclohexylmethane; and 1,3-bis(aminomethyl)cyclohexane. Exemplary six-membered ring diamines include, for example, piperazine and 1,4-diazabicyclo[2.2.2]octane ("DABCO").

[0106] Other useful polyamines include those having at least three amino groups, which may be primary, secondary, or a combination thereof. Examples include 3,3'-diaminobenzidine and hexamethylenetriamine.

[0107] Common curing agents used to cure alicyclic epoxy resins include anhydrides derived from carboxylic acids having at least one anhydride group. Such anhydride curing agents are described in U.S. Patent No. 6,194,024, which is incorporated herein by reference.

[0108] In one embodiment, the curable epoxy resin composition may be provided as a two-part composition. Generally, the two components of the two-part composition may be mixed before supplying the epoxy resin composition to the mold. At least a portion of the mold includes a negative mold replica of the microstructured surface described herein.

[0109] Compression molding of epoxy resin sheets In another embodiment, a component of a medical diagnostic device (e.g., a diaphragm of a stethoscope) is prepared by compression molding of an epoxy resin sheet, and the molded surface includes a negative-type replica of a microstructured surface.

[0110] Epoxy resin sheets are produced by applying heat and pressure to a layer of paper, canvas, linen, or glass cloth impregnated with a synthetic thermosetting epoxy resin containing a latent curing agent. Various types of resins and cloth materials can be used to produce thermosetting laminates with a variety of mechanical, thermal, and electrical properties. Curable epoxy resin sheets can be molded by bringing a mold surface into contact with the sheet and applying heat and pressure. The heat and pressure first soften the material so that a microstructured surface is replicated on the surface of the epoxy resin sheet. The heat also cures (i.e., fixes) the epoxy resin so that the microstructured surface is maintained. G-10 has a combination of good electrical properties, high strength, higher dimensional stability, and high moisture resistance. Typical properties of G-10 are as follows. Other materials with similar properties can also be used. [Table 2]

[0111] Method for thermoforming microstructured sheets In another embodiment, a method for manufacturing a medical diagnostic article or a component thereof is described, comprising providing a base member (e.g., a sheet or plate) having a microstructured surface. The base member comprises a thermoplastic or thermosetting material. The ridge structure comprises a different material from the base member such that the ridge structure has a higher melting temperature than the base member. The ridge structure typically comprises a cured polymerizable resin. The method comprises thermoforming the microstructured base member (e.g., a film, sheet, or plate) into an article at a temperature below the melting temperature of the ridge structure. In some embodiments, vacuum forming may be used in combination with thermoforming, also known as double vacuum thermoforming (DVT). In some embodiments, the thermoformed article may be a three-dimensional shell, such as an ultrasonic probe cap.

[0112] A base member (e.g., a sheet) can be prepared as described in U.S. Patent No. 5,175,030 of Lu et al. and U.S. Patent No. 5,183,597 of Lu, and an article having a microstructure (e.g., a brightness-enhancing film) can be prepared by a method comprising: (a) preparing a polymerizable composition; (b) depositing the polymerizable composition on a master negative microstructure mold surface in an amount just sufficient to fill the cavities of the master; (c) filling the cavities by moving polymerizable composition beads between a pre-formed base (such as a monolithic or multilayer (e.g., PET film)) and the master (at least one of which is flexible); and (d) curing the composition. The master may be a metal such as nickel, nickel-plated copper, or brass, or a thermoplastic material which is stable under polymerization conditions and preferably has a surface energy that allows for clean removal of the polymerized material from the master. One or more surfaces of the base film may optionally be primed, or, if not primed, treated to facilitate adhesion of the optical layer to the base.

[0113] Useful base material members include, for example, styrene-acrylonitrile, cellulose acetate-butyrate, cellulose propionate acetate, cellulose triacetate, polyethersulfone, polymethyl methacrylate, polyurethane, polyester, polycarbonate, polyvinyl chloride, polystyrene, polyethylene naphthalate, copolymers or blends based on naphthalenedicarboxylic acid, polycycloolefin, polyimide, and glass. Optionally, the base material may contain mixtures or combinations of these materials. In one embodiment, the base portion may be multilayered or may contain dispersed components suspended or dispersed in a continuous phase. Examples of useful PET films include photograde polyethylene terephthalate and MELINEX® PET, available from DuPont Film (Wilmington, Del). An example of a useful thermoformable material is polyethylene terephthalate (polyester containing glycol), commercially available as VIVAK PETG. Such materials are characterized by having a tensile strength in the range of 5,000 to 10,000 psi (ATMD 638) and a flexural strength of 5,000 to 15,000 (ASTM D-790). Such materials have a glass transition temperature of 178°F (ASTM D-3418).

[0114] Various polymerizable resins suitable for the manufacture of microstructured films are described. In a typical embodiment, the polymerizable resin comprises at least one (meth)acrylate monomer or oligomer containing at least two (meth)acrylate groups (e.g., Photomer 6210) and a (e.g., multi(meth)acrylate) crosslinking agent (e.g., HDDA). The polymerizable resin may also be filled with suitable organic or inorganic fillers, which, in specific applications, are radiopaque.

[0115] The materials for retroreflective sheets and brightness-enhancing films are selected based on their optical properties. Therefore, the peaks and adjacent valleys typically include materials with refractive indices of at least 1.50, 1.55, or 1.60. Furthermore, the visible light transmittance is typically greater than 85% or 90%. However, for many embodiments of the films, methods, and articles described herein, optical properties may not be critical. Therefore, a variety of other materials with lower refractive indices, including colored materials, light-transmitting materials, and opaque materials, can be used. In some embodiments, the microstructured film or sheet may further include printed graphics.

[0116] In alternative embodiments, the materials of the microstructure and the (e.g., planar) base member may be selected to provide specific optical properties in addition to the improved microbial removal and / or reduced contact migration described herein.

[0117] For example, in one embodiment, the base member (e.g., planar) is a multilayer optical film comprising at least a plurality of alternating first and second optical layers, wherein the first and second optical layers collectively reflect at least 30 percent of incident ultraviolet light over a wavelength reflection bandwidth of at least 30 nanometers in the wavelength range of 100 nanometers to 280 nanometers at at least one of the incident light angles of 0°, 30°, 45°, 60°, or 75°. Such a multilayer optical film is described in International Publication No. 2020 / 070589, which is incorporated herein by reference, and is useful as a UV-C shield, a UV-C optical collimator, and a UV-C optical concentrator. In some embodiments, the incident visible light transmittance through at least a plurality of alternating first and second optical layers is greater than 30 percent over a wavelength reflection bandwidth of at least 30 nanometers in the wavelength range of at least 400 nanometers to 750 nanometers. The first optical layer may comprise at least one polyethylene copolymer. The second optical layer may comprise at least one of a copolymer comprising tetrafluoroethylene, hexafluoropropylene, and vinylidene fluoride, a copolymer comprising tetrafluoroethylene and hexafluoropropylene, or a perfluoroalkoxyalkane. The first optical layer may comprise titania, zirconia, zirconium oxynitride, hafnia, or alumina. The second optical layer may comprise at least one of silica, aluminum fluoride, or magnesium fluoride. In some embodiments, the microstructure, together with the multilayer optical film, provides a visible light-transmitting UV-C (e.g., reflective) protective layer, or in other words, a UV-C shield. While surfaces can be disinfected using UVC light, these wavelengths can damage organic materials and cause undesirable discoloration. By combining the microstructured surfaces described herein with a UV-C shield, the surface can be disinfected by cleaning with both UVC light and conventional cleaning methods (e.g., wiping, scrubbing, and / or application of antimicrobial solutions).

[0118] As shown in Figure 3, a continuous land layer 360 may exist between the bottom of a channel or valley and the upper surface 331 of the (e.g., planar) base member 310. In some embodiments, when the microstructured surface is prepared by casting and curing a polymerizable resin composition, the thickness of the land layer is typically at least 0.5, 1, 2, 3, 4, or 5 microns, and up to a maximum of 50 microns. In some embodiments, the thickness of the land layer is 45, 40, 35, 30, 25, 20, 15, or 10 microns or less.

[0119] In some embodiments, the microstructured surface (e.g., at least its ridge structure) comprises an organic polymer material having a glass transition temperature of at least 25°C (measured by differential scanning calorimeter). In some embodiments, the organic polymer material has a glass transition temperature of at least 30, 35, 40, 45, 50, 55, or 60°C. In some embodiments, the organic polymer material has a glass transition temperature of at least 100, 95, 90, 85, 80, or 75°C. In other embodiments, the microstructured surface (e.g., at least its ridge structure) comprises an organic polymer material having a glass transition temperature of less than 25°C or less than 10°C (measured by differential scanning calorimeter). In at least some embodiments, the microstructure may be an elastomer. Elastomers can generally be understood as polymers having viscoelastic (or elastic) properties with preferably low Young's modulus and high yield strain compared to other materials. This term is often used interchangeably with the term rubber, but the latter is preferred when referring to crosslinked polymers.

[0120] In one embodiment, a microstructure or microstructured surface may be made of a curable thermosetting material. Unlike thermoplastic materials, which are thermally reversible in melting and solidifying, thermosetting plastics harden after heating, so they are initially thermoplastic but become unmeltable after hardening, or their melting temperature becomes significantly higher after hardening.

[0121] In some embodiments, the thermosetting material is predominantly a silicone polymer by weight. In at least some embodiments, the silicone polymer is a polydialkoxysiloxane such as poly(dimethylsiloxane) (PDMS), and the microstructures are made from a material which is predominantly PDMS by weight. More specifically, the microstructures may be all or substantially all PDMS. For example, each microstructure may be more than 95% by weight. In certain embodiments, the PDMS is a cured thermosetting composition formed by hydrosilylation of a silicone hydride (Si-H) functionalized PDMS with an unsaturated functionalized PDMS such as a vinyl functionalized PDMS. The Si-H and unsaturated groups may be terminal, pendant, or both. In other embodiments, the PDMS may be a moisture-curable type such as an alkoxysilane-terminated PDMS.

[0122] In some embodiments, other silicone polymers besides PDMS may be useful, for example, silicones having other groups where some of the silicon atoms may be aryl, e.g., phenyl, alkyl, e.g., ethyl, propyl, butyl, or octyl, fluoroalkyl, e.g., 3,3,3-trifluoropropyl, or arylalkyl, e.g., 2-phenylpropyl. Silicone polymers may also contain reactive groups such as vinyl, silicon hydride (Si-H), silanol (Si-OH), acrylate, methacrylate, epoxy, isocyanate, anhydride, mercapto, and chloroalkyl. These silicones may be thermoplastic or cured by, for example, condensation curing, addition curing of vinyl and Si-H groups, or free radical curing of pendant acrylate groups. They may also be crosslinked with the use of peroxides. Such curing can be achieved by the addition of heat or chemical rays.

[0123] Other polymers useful for microstructures or microstructured surfaces may be thermoplastic or thermosetting polymers, and include polyurethanes, polyolefins including metallocene polyolefins, low-density polyethylene, polypropylene, ethylene methacrylate copolymers; polyesters (elastomer polyesters (e.g., Hytrel)), biodegradable polyesters (polylactic acid, polylactic acid / glycolic acid, copolymers of succinic acid and diols, and equivalents), fluoropolymers including fluoroelastomers, and acrylics (polyacrylates and polymethacrylates).

[0124] Polyurethane may be linear, thermoplastic, or thermosetting. Polyurethane may be formed from a polyester polyol or polyether polyol, or a combination thereof, and an aromatic or aliphatic isocyanate.

[0125] Representative fluoropolymers include, for example, polyvinyl fluoride (PVF); polyvinylidene fluoride (PVDF); ethylene tetrafluoroethylene (ETFE); copolymers of tetrafluoroethylene, hexafluoropropylene, and vinylidene fluoride (THV); polyethylene copolymers containing subunits derived from tetrafluoroethylene (TFE), hexafluoropropylene (HFP), and vinylidene fluoride (VDF); and fluorinated ethylene propylene (FEP) copolymers. Fluoropolymers are commercially available from Dyneon LLC (Oakdale, MN), Daikin Industries, Ltd. (Osaka, Japan); Asahi Glass Co., Ltd. (Tokyo, Japan) and EIdu Pont de Nemours and Co. (Wilmoniton, DE).

[0126] In some embodiments, the microstructured film or microstructured surface layer includes a multilayer film containing a fluoropolymer, such as that described in the previously cited International Publication No. 2020 / 070589. Such a multilayer film is useful, for example, as a UV-C shield, a UV-C collimator, and a UV-C light concentrator. In other embodiments, the microstructured film or microstructured surface layer includes a monolithic or multilayer fluoropolymer (e.g., protective) layer that is not useful as a UV-C shield, a UV-C collimator, or a UV-C light concentrator.

[0127] In some embodiments, the microstructure or microstructured surface may be modified to make the microstructured surface more hydrophilic. Generally, the microstructured surface may be modified such that a flat organic polymer film surface of the same material as the modified microstructured surface exhibits an advancing or receding contact angle of 45 degrees or less with deionized water. Without such modification, a flat organic polymer film surface of the same material as the microstructured surface typically exhibits an advancing or receding contact angle of 45, 50, 55, or 60 degrees or more with deionized water.

[0128] Any suitable known method may be used to realize a hydrophilic microstructured surface. Surface treatments such as plasma treatment, vacuum deposition, polymerization of hydrophilic monomers, grafting of hydrophilic portions onto a film surface, and corona or flame treatment may be used. In certain embodiments, the hydrophilic surface treatment includes a zwitterionic silane, and in certain embodiments, the hydrophilic surface treatment includes a non-zwitterionic silane. Examples of non-zwitterionic silanes include non-zwitterionic anionic silanes.

[0129] In other embodiments, the hydrophilic surface treatment further comprises at least one silicate, including, but not limited to, lithium silicate, sodium silicate, potassium silicate, silica, tetraethyl orthosilicate, poly(diethoxysiloxane), or a combination thereof. One or more silicates may be mixed in a solution containing a hydrophilic silane compound for application to a microstructured surface.

[0130] Optionally, surfactants or other suitable agents may be added to the organic polymer composition used to form the microstructured surface. For example, hydrophilic acrylates and initiators may be added to the polymerizable composition and polymerized by heat or chemical radiation. Alternatively, the microstructured surface can be formed from hydrophilic polymers, which include homopolymers and copolymers of ethylene oxides; hydrophilic polymers incorporating vinyl unsaturated monomers such as vinylpyrrolidone, carboxylic acids, sulfonic acids, or phosphonic acid-functional acrylates such as acrylic acid; hydroxyethyl acrylates, vinyl acetate and its hydrolyzed derivatives (e.g., polyvinyl alcohol); acrylamide; polyethoxylated acrylates; hydrophilic modified cellulose; and polysaccharides such as starch and modified starch, and dextran.

[0131] Such hydrophilic surfaces are described for use in fluid control films, as described in U.S. Patent Application Publication No. 2017 / 0045284, incorporated herein by reference.

[0132] Bonding of microstructured films to medical diagnostic articles or their components. In some embodiments, the (e.g., processed) microstructured surface may be provided as a film or tape and can be attached to the (e.g., external) surface of a medical diagnostic article or its components. Fixation may be provided using mechanical bonding, adhesives, heat treatment such as thermal welding, ultrasonic welding, RF welding, or a combination thereof.

[0133] In one embodiment, a film (e.g., tape) comprising a microstructured surface as described herein, disposed on a planar base layer, is described. The microstructure may be made of the same material as the planar base layer, or of a different material.

[0134] The film (e.g., tape) includes a pressure-sensitive adhesive (e.g., 350 in Figure 3) on the opposite side of the film. By adhering the film to a surface with the pressure-sensitive adhesive, a microstructured surface can be provided on the surface of a medical diagnostic article or its components.

[0135] The planar base layer may undergo conventional surface treatment for better adhesion to adjacent (e.g., pressure-sensitive) adhesive layers. Furthermore, the base member may undergo conventional surface treatment for better adhesion to (e.g., cast and cured) microstructured layers to the underlying base member. Examples of surface treatments include exposure to ozone, exposure to flame, exposure to high-voltage electric shock, ionizing radiation treatment, and other chemical or physical oxidation treatments. Examples of chemical surface treatments include primers. Examples of suitable primers include chlorinated polyolefins, polyamides, modified polymers disclosed in U.S. Patent Nos. 5,677,376 and 5,623,010, as well as those disclosed in International Publication Nos. 98 / 15601 and 99 / 03907, and other modified acrylic polymers. In one embodiment, the primer is an organic solvent-based primer containing an acrylate polymer, a chlorinated polyolefin, and an epoxy resin, available from 3M Company as "3M® Primer 94".

[0136] The film may contain various (e.g., pressure-sensitive) adhesives, such as natural or synthetic rubber-based pressure-sensitive adhesives, acrylic pressure-sensitive adhesives, vinyl alkyl ether pressure-sensitive adhesives, silicone pressure-sensitive adhesives, polyester pressure-sensitive adhesives, polyamide pressure-sensitive adhesives, poly-α-olefin, polyurethane pressure-sensitive adhesives, and styrene block copolymer-based pressure-sensitive adhesives. The pressure-sensitive adhesive can generally be measured by dynamic viscoelasticity measurement at room temperature (25°C) at a frequency of 1 Hz, with a pressure sensitivity of 3 × 10⁻⁶. 6 It has a storage modulus (E') of less than dyne / cm.

[0137] In some embodiments, the pressure-sensitive adhesive may be natural rubber-based, meaning that the natural rubber elastomer constitutes at least about 20% by weight of the elastomer component of the adhesive (which contains no fillers, tackifiers, etc.). In further embodiments, the natural rubber elastomer constitutes at least about 50% by weight, or at least about 80% by weight, of the elastomer component of the adhesive. In some embodiments, the natural rubber elastomer may be blended with one or more block copolymer thermoplastic elastomers (e.g., the general type available from Kraton Polymers (Houston, TX) under the trade name KRATON). In certain embodiments, the natural rubber elastomer may be blended with a styrene-isoprene radical block copolymer in combination with at least one tackifier. This type of adhesive composition is disclosed in further detail in U.S. Patent Application Publication 2003 / 0215628 by Ma et al.

[0138] The (e.g., pressure-sensitive) adhesive may be an organic solvent-based, aqueous emulsion, hot melt (e.g., as described in U.S. Patent No. 6,294,249), or chemical beam (e.g., electron beam, ultraviolet) curable (e.g., pressure-sensitive) adhesive.

[0139] In some embodiments, the adhesive layer is removable. The removable adhesive is temporarily bonded to a substrate or surface (e.g., glass or polypropylene panel) after aging at 50, 60, 70, 80, 90, 100, or 120°C (248°F) for 4 hours, then equilibrated to 25°C and cleanly removed from the substrate or surface at a removal rate of approximately 20 inches / minute.

[0140] In some embodiments, the adhesive layer is a repositionable adhesive layer. The term “repositionable” means that, at least initially, it can be repeatedly adhered to and removed from a substrate without substantially impairing its adhesive properties. Repositionable adhesives typically have a peel strength to the substrate surface that is lower than that of conventional strong adhesive PSAs, at least initially. Suitable repositionable adhesives include the types of adhesives used in the CONTROLTAC Plus Film and SCOTCHLITE Plus Sheeting brands, both manufactured by 3M Company (St. Paul, Minnesota, USA).

[0141] The adhesive layer may also be a structured adhesive layer, or an adhesive layer having at least one microstructured surface. When a film article containing such a structured adhesive layer is applied to a substrate surface, channels or a network of similar structures exist between the film article and the substrate surface. The presence of such channels or similar structures allows air to pass horizontally through the adhesive layer, thereby removing air from beneath the film article and the surface substrate during application.

[0142] Topologically structured adhesives can also be used to provide repositionable adhesives. For example, it has been reported that relatively large-scale adhesive embossing permanently reduces the pressure-sensitive adhesive / substrate contact area, thereby also reducing the adhesive strength of the pressure-sensitive adhesive. Various topologies include concave and convex V-grooves, diamonds, cups, hemispheres, cones, crater shapes, and other three-dimensional shapes, all of which have an upper surface area significantly smaller than the base surface of the adhesive layer. Generally, these topologies provide adhesive sheets, films, and tapes with lower peel adhesion values ​​compared to adhesive layers with smooth surfaces. In many cases, adhesives with these topologically structured surfaces have also been shown to build adhesion more slowly with increasing contact time.

[0143] Adhesive layers having a microstructured adhesive surface may include adhesive or composite adhesive "pegs" that are uniformly distributed across the entire functional portion of the adhesive surface and protrude outward from the adhesive surface. Film articles having such adhesive layers provide a repositionable sheet material when placed on a substrate surface (see U.S. Patent No. 5,296,277). Such adhesive layers also require a matching microstructured release liner to protect the adhesive pegs during storage and processing. The formation of a microstructured adhesive surface can also be achieved, for example, by coating an adhesive onto a release liner with a corresponding micro-embossed pattern, or by pressing an adhesive (e.g., PSA) onto a release liner with a corresponding micro-embossed pattern, as described in International Publication No. 98 / 29516.

[0144] If desired, the adhesive layer may include multiple adhesive sublayers to obtain a combined adhesive layer assembly. For example, the adhesive layer may include a hot melt adhesive sublayer along with a continuous or discontinuous PSA or repositionable adhesive coating layer.

[0145] Acrylic pressure-sensitive adhesives can be manufactured by free radical polymerization techniques such as solution polymerization, bulk polymerization, or emulsion polymerization. The acrylic polymer may be any type, such as random copolymer, block copolymer, or graft polymer. Polymerization may be carried out using any of the commonly used polymerization initiators and chain transfer agents.

[0146] The acrylic pressure-sensitive adhesive contains polymerization units of one or more (meth)acrylate ester monomers derived from an alcohol (e.g., a non-tertiary) containing 1 to 14 carbon atoms, preferably an average of 4 to 12 carbon atoms. Examples of monomers include esters of non-tertiary alcohols such as ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, 1-pentanol, 2-pentanol, 3-pentanol, 2-methyl-1-butanol, 3-methyl-1-butanol, 1-hexanol, 2-hexanol, 2-methyl-1-pentanol, 3-methyl-1-pentanol, 2-ethyl-1-butanol; 3,5,5-trimethyl-1-hexanol, 3-heptanol, 1-octanol, 2-octanol, isooctyl alcohol, 2-ethyl-1-hexanol, 1-decanol, 2-propylheptanol, 1-dodecanol, 1-tridecanol, and 1-tetradecanol with either acrylic acid or methacrylic acid.

[0147] Acrylic pressure-sensitive adhesives contain polymerization units of one or more low Tg (meth)acrylate monomers, that is, when they react to form a homopolymer, the (meth)acrylate monomers have a T below 0°C. g It has. In some embodiments, the low Tg monomer has a T of -5°C or below, or -10°C or below. g These homopolymers have the following characteristics: The Tg of these homopolymers is often -80°C or higher, -70°C or higher, -60°C or higher, or -50°C or higher.

[0148] Low Tg monomers may have the following formula: H2C=CR 1 C(O)OR 8 [In the formula, R 1 is H or methyl, and R 8 [The alkyl group is an alkyl group having 1 to 22 carbon atoms, or a heteroalkyl group having 2 to 20 carbon atoms and 1 to 6 heteroatoms selected from oxygen or sulfur.] The alkyl group or heteroalkyl group can be linear, branched, cyclic, or a combination thereof.

[0149] Examples of low Tg monomers include ethyl acrylate, n-propyl acrylate, n-butyl acrylate, isobutyl acrylate, t-butyl acrylate, n-pentyl acrylate, isoamyl acrylate, n-hexyl acrylate, 2-methylbutyl acrylate, 2-ethylhexyl acrylate, 4-methyl-2-pentyl acrylate, n-octyl acrylate, 2-octyl acrylate, isooctyl acrylate, isononyl acrylate, decyl acrylate, isodecyl acrylate, lauryl acrylate, isotridecyl acrylate, octadecyl acrylate, and dodecyl acrylate.

[0150] Examples of low-Tg heteroalkyl acrylate monomers include, but are not limited to, 2-methoxyethyl acrylate and 2-ethoxyethyl acrylate.

[0151] In a typical embodiment, the acrylic pressure-sensitive adhesive comprises a polymerization unit of at least one low-Tg monomer having an alkyl group containing 6 to 20 carbon atoms. In some embodiments, the low-Tg monomer has an alkyl group containing 7 or 8 carbon atoms. Exemplary monomers include, but are not limited to, esters of (meth)acrylic acid with alcohols derived from renewable resources, such as 2-ethylhexyl (meth)acrylate, isooctyl (meth)acrylate, n-octyl (meth)acrylate, isodecyl (meth)acrylate, lauryl (meth)acrylate, and 2-octyl (meth)acrylate.

[0152] Acrylic pressure-sensitive adhesives typically contain, based on the total weight of polymerization units (i.e., excluding inorganic fillers or other additives), at least 50, 55, 60, 65, 70, 75, 80, 85, or 90% by weight of polymerization units of monofunctional alkyl (meth)acrylate monomers having a Tg below 0°C.

[0153] The acrylic pressure-sensitive adhesive may further contain at least one high-Tg monomer, i.e., the (meth)acrylate monomer has a Tg higher than 0°C when reacting to form a homopolymer. High-Tg monomers more typically have a Tg higher than 5°C, 10°C, 15°C, 20°C, 25°C, 30°C, 35°C, or 40°C. Examples of high-Tg monofunctional alkyl (meth)acrylate monomers include t-butyl acrylate, methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, s-butyl methacrylate, t-butyl methacrylate, stearyl methacrylate, phenyl methacrylate, cyclohexyl methacrylate, isobornyl acrylate, isobornyl methacrylate, norbornyl (meth)acrylate, benzyl methacrylate, 3,3,5-trimethylcyclohexyl acrylate, cyclohexyl acrylate, N-octylacrylamide, and propyl methacrylate or combinations thereof.

[0154] The acrylic pressure-sensitive adhesive may further contain polymerization units of polar monomers. Typical polar monomers include, for example, acid-functional monomers (e.g., acrylic acid, methacrylic acid), hydroxyl-functional (meth)acrylate monomers, nitrogen-containing monomers (e.g., acrylamide), and combinations thereof. In some embodiments, the acrylic pressure-sensitive adhesive contains polymerization units of polar monomers such as acrylamide and / or acid-functional monomers such as (meth)acrylic acid in amounts of at least 0.5, 1, 2, or 3% by weight, and typically 10% by weight or less.

[0155] The (for example, pressure-sensitive) adhesive may further contain one or more suitable additives as needed. Examples of additives include crosslinking agents (e.g., polyfunctional (meth)acrylate crosslinking agents (e.g., HDDA, TMPTA), epoxy crosslinking agents, isocyanate crosslinking agents, melamine crosslinking agents, aziridine crosslinking agents, etc.), tackifiers (e.g., phenol-modified terpenes and rosin esters such as glycerol esters of rosin and pentaerythritol esters of rosin, as well as C5 and C9 hydrocarbon tackifiers), thickeners, plasticizers, fillers, antioxidants, UV absorbers, antistatic agents, surfactants, leveling agents, colorants, flame retardants, and silane coupling agents.

[0156] The (e.g., pressure-sensitive) adhesive layer can be applied to the film by various conventional coating methods, such as (e.g., gravure) roller coating, flow coating, dip coating, spin coating, spray coating, knife coating, (e.g., rotary or slit) die coating, (e.g., hot melt) extrusion coating, and printing. The adhesive may be applied directly to the substrate described herein, or it may be transferred using a release liner. When using a release liner, the adhesive is either coated onto the liner and laminated onto the film, or coated onto the film and then the release liner is applied to the adhesive layer. The adhesive layer can be applied as a continuous layer or as a patterned discontinuous layer. The adhesive layer typically has a thickness of about 5 to 50 μm.

[0157] Release liners typically include paper or film coated or modified with low surface energy compounds such as organosilicone compounds, fluoropolymers, polyurethanes, and polyolefins. These release liners may also be polymer sheets made from polyethylene, polypropylene, PVC, or polyester, with or without the addition of adhesive-repellent compounds. As described above, release liners may have microstructured patterns or fine embossed patterns to impart structure to the adhesive layer. Microstructured release liners can also be used to impart a microstructured surface and protect the microstructured surface from damage before or during application to a target surface or article.

[0158] Microstructured films attached to the surface of medical diagnostic articles or their components can be prepared by casting and curing polymerizable resin onto a thermoplastic or thermosetting film, as described above. Alternatively, microstructured films may be prepared by melt extrusion molding or embossing of thermoplastic films.

[0159] Other useful thermoplastic or thermosetting polymers include polyurethanes, polyolefins including metallocene polyolefins; polyesters (e.g., elastomer polyesters (e.g., Hytrel)); biodegradable polyesters (e.g., polylactic acid, polylactic acid / glycolic acid, copolymers of succinic acid and diols, and equivalents); fluoropolymers including fluoroelastomers; and acrylics (polyacrylates and polymethacrylates). Polyurethanes may be linear and may be thermoplastic or thermosetting. Polyurethanes may be formed from polyester polyols or polyether polyols or combinations thereof, and combined aromatic or aliphatic isocyanates.

[0160] Referring again to Figures 2-4 and 6, the articles described herein typically include (e.g., processed) microstructured surfaces (200, 300, 400, 600) placed on base members (210, 310, 410, 610). If the article is a film (e.g., a sheet), the base members are flat (e.g., parallel to the reference plane 126). The thickness of the base members is typically at least 10, 15, 20, or 25 microns (1 mil), and typically 500 microns (20 mil) or less. In some embodiments, the thickness of the base members is 400, 300, 200, or 100 microns or less. (e.g., a film) The width of the base members is at least 30 inches (122 cm), and preferably at least 48 inches (76 cm). The (e.g., film) base material may be continuous in length of up to approximately 50 yards (45.5 m) to 100 yards (91 m), thereby providing the microstructured film in a conveniently handled roll product form. However, alternatively, the (e.g., film) base material may be individual sheets or strips (e.g., tape) rather than a roll product.

[0161] Thermoformable microstructured base members typically have a thickness of at least 50, 100, 200, 300, 400, or 500 microns. Thermoformable microstructured base members may have a maximum thickness of 3, 4, or 5 mm or more.

[0162] Medical diagnostic materials Medical diagnostic articles or their components may be formed from materials such as metals, alloys, organic polymer materials, or combinations including at least one of the aforementioned. Specifically, glass, ceramics, metals, or polymer materials, as well as other suitable substitutes and combinations thereof, such as ceramic-coated polymers, ceramic-coated metals, polymer-coated metals, and metal-coated polymers, may be appropriate.

[0163] The polymer used to form the substrate can be biodegradable, non-biodegradable, or a combination thereof.

[0164] Furthermore, fiber-reinforced polymers and / or particle-reinforced polymers can also be used.

[0165] Furthermore, fiber-reinforced polymers and / or particle-reinforced polymers can also be used. Non-limiting examples of suitable non-biodegradable polymers include polyolefins (e.g., polyisobutylene copolymers), styrene block copolymers (e.g., styrene-isobutylene-styrene block copolymers such as styrene-isobutylene-styrene-tert-block copolymers (SIBS)); polyvinylpyrrolidones (including crosslinked polyvinylpyrrolidones); polyvinyl alcohols; copolymers of vinyl monomers (such as EVA and polyvinyl chloride (PVC)); polyvinyl ethers; polyvinyl aromatics; polyethylene oxides; polyesters (such as polyethylene terephthalate); polyamides; polyacrylamides; polyethers (such as polyethersulfones); polyolefins (such as polypropylene, polyethylene, highly crosslinked polyethylene, and high or ultra-high molecular weight polyethylene); polyurethanes; polycarbonates; silicones; siloxane polymers; natural-based polymers (optionally modified polysaccharides and proteins, but not limited to these, including cellulose polymers and cellulose esters (such as cellulose acetate)); and combinations comprising at least one of the aforementioned polymers. The combinations may include miscible and miscible blends, as well as laminates.

[0166] Suitable non-limiting examples of biodegradable polymers include polycarboxylic acids; polyanhydrides (such as maleic anhydride polymers); polyorthoesters; polyamino acids; polyethylene oxides; polyphosphazenes; polylactic acid, polyglycolic acid, and copolymers and mixtures thereof (poly(L-lactic acid)(PLLA), poly(D,L,lactide), poly(lactic acid-coglycolic acid), and (D,L,lactide-coglycolic acid) in a 50 / 50 weight ratio); polydioxanone; polypropylene fumarate; polydepsipeptides; polycaprolactone and copolymers, and mixtures thereof (poly(D,L,lactide-caprolactone) and Examples include polycaprolactone co-butyl acrylate, etc.; polyhydroxybutyrate valerate and mixtures thereof; polycarbonates (tyrosine-derived polycarbonates and arylates, polyiminocarbonates, and polydimethyltrimethylcarbonate); cyanoacrylates; calcium phosphate; polyglycosum glycosides; macromolecules (polysaccharides (including hyaluronic acid), cellulose, and hydroxypropyl methylcellulose, etc.); gelatin; starch; dextran; and alginic acid and its derivatives, proteins and polypeptides; as well as mixtures and copolymers of any of the above. Biodegradable polymers may also be surface-eroding polymers such as polyhydroxybutyrate and its copolymers, polycaprolactone, polyanhydrides (both crystalline and amorphous), and maleic anhydride.

[0167] In some embodiments, the microstructured surface may be integrated with a medical diagnostic device or at least a portion of its components. In other embodiments, the microstructured surface may be provided as a film or tape that can be attached to a medical diagnostic device or at least a portion of its components. In such embodiments, the microstructure may be made of the same material as the base member or a different material. Fixation may be provided using mechanical bonding, adhesives, thermal welding, ultrasonic welding, RF welding or other heat treatments, or a combination thereof.

[0168] In some embodiments, the base member (e.g., planar) is flexible, similar to a microstructured film. In some embodiments, the film (e.g., graphic) is sufficiently flexible and conformable to shape so that it can be applied to complex curved (e.g., three-dimensional) surfaces (e.g., bonded with adhesive). In some embodiments, the base member (e.g., planar) is flexible, similar to a microstructured film, and has an elongation of at least 50, 75, 100, 125, 150, or 200%. In some embodiments, the base member (e.g., planar) is flexible, similar to a microstructured film, and has an elongation of 500, 450, 400, 350, 300, or 250% or less. In some embodiments, the base member (e.g., planar) is flexible, similar to a microstructured film, and has a tensile modulus of 1000, 750, or 500 MPa or less. The tensile modulus is typically at least 100, 150, or 200 MPa. In some embodiments, the base member (e.g., planar) as well as the microstructured film has a tensile strength of 50, 40, or 30 MPa or less. The tensile strength is typically at least 10, 15, 20, or 25 MPa. The tensile test is determined according to ASTM D882-10, with an initial grip distance of 1 inch, a speed of 1 inch / min, or 100% strain / min.

[0169] Optional additives and coatings The microstructured surface organic polymer material may contain other additives, including antimicrobial agents (including bactericides and antibiotics), dyes, mold release agents, antioxidants, plasticizers, heat and light stabilizers (including ultraviolet (UV) absorbers), and fillers.

[0170] A suitable antimicrobial agent can be incorporated into the polymer or deposited on the polymer. Suitable antimicrobial agents include those described in Scholz et al.'s U.S. Patent Application Publications 2005 / 0089539 and 2006 / 0051384, and Scholz's U.S. Patent Application Publications 2006 / 0052452 and 2006 / 0051385. The microstructures of the present invention may also be coated with an antimicrobial coating, such as that disclosed in Ali et al.'s International Application PCT / US2011 / 37966.

[0171] In a typical embodiment, the microstructured surface is not prepared from a low surface energy material (e.g., fluorinated (e.g., fluoropolymer) or PDMS), does not include a low surface energy coating, and the material or coating on the flat surface has a receding contact angle with water greater than 90, 95, 100, 105, or 110 degrees. In this embodiment, the low surface energy of the material does not contribute to cleanability. Rather, the improved cleanability is due to the characteristics of the microstructured surface. In this embodiment, the microstructured surface is prepared from a material such that the flat surface of the material typically has a receding contact angle with water less than 90, 85, or 80 degrees.

[0172] In other embodiments, low surface energy coatings may be applied to microstructures. Examples of exemplary low surface energy coating materials that may be used include hexafluoropropylene oxide (HFPO) or organosilanes (e.g., alkylsilanes, alkoxysilanes, acrylicsilanes, polyhedral oligomeric silsesquioxanes (POSS), and fluorine-containing organosilanes). Examples of specific coatings known in the art can be found, for example, in U.S. Patent Application Publication 2008 / 0090010 and U.S. Patent Publication 2007 / 0298216, published by the same owner. In embodiments where the coating is applied to a microstructure, it may be applied by any suitable coating method, such as sputtering, vapor deposition, spin coating, dip coating, roll-to-roll coating, or any number of other suitable methods.

[0173] To maintain the fidelity of the microstructure, the composition used to form the microstructure may, and often preferentially, include a surface energy modifying compound. In some embodiments, the bloom additive can delay or prevent the crystallization of the base composition. Suitable bloom additives can be found, for example, in Scholz et al., International Publication No. 2009 / 152345, and Klun et al., U.S. Patent No. 7,879,746.

[0174] Cleaning of microstructured surfaces One embodiment describes a method for providing a medical diagnostic article having a surface with improved removal of microorganisms (e.g., bacteria) during cleaning. The microstructured surface can be mechanically cleaned, for example, by wiping the microstructured surface with a woven or nonwoven material, or by scrubbing the microstructured surface with a brush. In some embodiments, the fibers of the woven or nonwoven material have a fiber diameter smaller than the maximum width of the grooves. In some embodiments, the bristles of the brush have a diameter smaller than the maximum width of the grooves. Alternatively, the microstructured surface may be cleaned by applying an antimicrobial solution to the microstructured surface. Furthermore, the microstructured surface can also be cleaned by radiation disinfection (e.g., ultraviolet light). A combination of such cleaning techniques can be used.

[0175] The antimicrobial solution may contain a bactericidal component. Various bactericidal components are known, including, but are not limited to, chlorhexidine and its various salts (digluconate, diacetate, dimethosulfate, and dilactate salts, and combinations thereof), biguanides and bisbiguanides such as high molecular weight quaternary ammonium compounds such as polyhexamethylene biguanide; silver and various silver complexes; small molecule quaternary ammonium compounds (such as benzalkonium chloride and alkyl-substituted derivatives); di-long chain alkyl (C8-C18) quaternary ammonium compounds; cetylpyridinium halides and their derivatives; benzethonium chloride and its alkyl-substituted derivatives; octenidine, and compatible combinations thereof. In other embodiments, the antimicrobial component may be a cationic antimicrobial agent or oxidizing agent such as hydrogen peroxide, peracetic acid, or a bleaching agent.

[0176] In some embodiments, the antimicrobial component is a small molecule quaternary ammonium compound. Examples of preferred quaternary ammonium bactericides include benzalkonium halides having alkyl chain lengths of C8-C18, more preferably C12-C16, and most preferably a mixture of chain lengths. For example, a typical benzalkonium chloride sample may consist of 40% C12 alkyl chains, 50% C14 alkyl chains, and 10% C16 alkyl chains. These are commercially available from numerous sources, including Lonza (Barquat MB-50), where the benzalkonium halides are substituted with alkyl groups on the phenyl ring. A commercially available example is Barquat 4250 from Lonza, which is a dimethyldialkylammonium halide with alkyl groups having chain lengths of C8-C18. Mixes of chain lengths (such as a mixture of dioctyl, dilauryl, and dioctadecyl) may be particularly useful. Exemplary compounds include Bardac 2050, 205M, and 2250 from Lonza; cetylpyridinium halides such as cetylpyridinium chloride, available from Merrell Labs as Cepacol Chloride; benzethonium halides and alkyl-substituted benzethonium halides such as Hyamine 1622 and Hyamine 10X, available from Rohm and Haas; and commercially available octenidine.

[0177] In one embodiment, the antimicrobial solution (for example, disinfection) kills enveloped viruses (e.g., herpesvirus, influenza, hepatitis B), non-enveloped viruses (e.g., papillomavirus, norovirus, rhinovirus, rotovirus), DNA viruses (e.g., poxvirus), RNA viruses (e.g., coronavirus, norovirus), retroviruses (e.g., HIV-1), MRSA, VRE, KPC, Acinetobacter, and other pathogens in 3 minutes. The aqueous disinfectant solution may contain a 1:256 dilution of a disinfectant concentrate containing benzyl-C12-16-alkyldimethylammonium chloride (8.9 wt%), octyldecyldimethylammonium chloride (6.67 wt%), dioctyldimethylammonium chloride (2.67 wt%), surfactant (5-10%), ethyl alcohol (1-3 wt%), and a chelating agent (7-10 wt%) adjusted to pH 1-3.

[0178] The term “microorganism” is generally used to refer to any microscopic prokaryotes or eukaryotes, including but not limited to one or more bacteria (e.g., motile or non-motile, growing or dormant, Gram-positive or Gram-negative, planktonic or biofilm-habitat), bacterial spores or endospores, algae, fungi (e.g., yeasts, filamentous fungi, mycospores), mycoplasmas, and protozoa, and combinations thereof. In some cases, the microorganisms in particular may be pathogenic, and the term “pathogen” is used to refer to any pathogenic microorganism. Examples of pathogens include, but are not limited to, both Gram-positive and Gram-negative bacteria, fungi, and viruses, and include members of the Enterobacteriaceae family, or members of the Micrococcaceae family, or species of Staphylococcus, Streptococcus, Pseudomonas, Acinetobacter, Enterococcus, Salmonella, Legionella, Shigella, Yersinia, Enterobacter, Escherichia, Bacillus, Listeria, Campylobacter, Acinetobacter, Vibrio, Clostridium, Klebsiella, Proteus, Aspergillus, Candida, and Corynebacterium genera. Specific examples of pathogens include, but are not limited to, Escherichia coli, including enterohemorrhagic Escherichia coli, e.g., serotypes O157:H7, O129:H11; Pseudomonas aeruginosa; Bacillus cereus; Bacillus anthracis; Salmonella enteritis; Salmonella typhimurium; Listeria monocytogenes; Clostridium botulinum; Clostridium perfringens; Staphylococcus aureus; methicillin-resistant Staphylococcus aureus; carbapenem-resistant Enterobacteriaceae Campylobacter jejuni; Yersinia parahaemolyticus; Vibrio vulnificus; Clostridium difficile; vancomycin-resistant enterococci; Klebsiella pneumoniae; Proteus mirabilis; and Enterobacter [Kronobacter] sakazakii.

[0179] The advantages of the present invention are further illustrated by the following embodiments, but the specific materials and their quantities, as well as other conditions and details described in these embodiments, should not be construed as unduly limiting the invention. Unless otherwise specified, all parts and percentages are by weight. [Examples]

[0180] [Table 3]

[0181] method Scanning electron microscopy - Sample preparation and imaging The sample discs were fixed for scanning electron microscopy (SEM) by carefully immersing each disc in a 5% glutaraldehyde solution for 30 minutes. This was followed by six consecutive disc immersion washing steps (30 minutes of immersion time for each step) in the following order: 1) PBS solution, 2) 25% isopropyl alcohol aqueous solution, 3) 50% isopropyl alcohol aqueous solution, 4) 75% isopropyl alcohol aqueous solution, and 5-6) two final immersion washes in 100% isopropyl alcohol solution. Each disc was transferred to a 96-well plate using tweezers. The discs were dried for approximately 48 hours. Next, the discs were individually attached to the SEM stub using double-sided tape, with the microstructured surface of the disc facing the outside of the stub. Conductive silver paint was applied to the edge of each sample, and the entire stub assembly was sputter coated for 90 seconds using Denton Vacuum Desk V Sputter Coater (Denton Vacuum (Moorestown, NJ)) and a gold target. After sputter coating, the stub was moved to a JEOL JCM-500 NeoScope SEM system (JEOL USA Incorporated (Peabody, MA)) for imaging.

[0182] Preparation of culture medium Trypsin soy broth (TSB, obtained from Becton, Dickinson and Company (Franklin Lakes, NJ)) was dissolved in deionized water and filtered and sterilized according to the manufacturer's instructions.

[0183] Brain Heart Infusion (BHIS, obtained from Becton, Dickinson and Company) was dissolved in deionized water and filtered and sterilized according to the manufacturer's instructions.

[0184] bacterial culture Streak plates of Pseudomonas aeruginosa (ATCC 15442) or Staphylococcus aureus (ATCC 6538) were prepared from frozen stocks of Tryptic Soy Agar. The plates were incubated overnight at 37°C. One colony was transferred from the plate to 10 mL of sterile TSB. The culture was shaken overnight at 250 rpm and 37°C. The inoculum was placed in the culture (approximately 10 9 The solution was prepared by diluting the colony-forming units (cfu) / mL in TSB at a ratio of 1:100.

[0185] An overnight culture of Streptococcus mutans (ATCC 25175) was grown by scraping a small amount of 25% glycerol frozen stock of the microorganism using a sterile serum pipette and transferring it to a 15 mL conical tube. This tube contained 5 mL of BHI broth. The tube was maintained at 37°C for 12–16 hours under static (no shaking) conditions. The inoculum was then transferred to this culture (approximately 10 9 The solution was prepared by diluting the colony-forming units (cfu) / mL in TSB at a ratio of 1:100.

[0186] Procedure for preparing microstructured films A UV-curable resin was prepared from PHOTOMER 6210 aliphatic urethane diacrylate oligomer (75 parts), SR238 1,6-hexanediol diacrylate (25 parts), and LUCIRIN TPO photoinitiator (0.5%). The components were blended in a high-speed mixer and heated in an oven at approximately 70°C for 24 hours, then cooled to room temperature. A copper button (2 inches (5.08 cm) in diameter) was used as a template for preparing a linear prism film. Both the button and the resin mixture were heated in an oven at approximately 70°C for 15 minutes. Approximately 6 drops of the heated resin were applied to the center of the heated button using a transfer pipette. A piece of MELINEX 618 PET support film [3 inches × 4 inches (7.62 cm × 10.16 cm), 5 mil thickness] was placed over the applied resin, followed by a glass plate. The primer-treated surface of the PET film was oriented to contact the resin. I pressed the glass plate in place by hand until the resin completely covered the surface of the button. I carefully removed the glass plate. If there were any air bubbles, I used a rubber hand roller to remove them.

[0187] The sample was cured with UV light by passing it twice through a UV processor (model QC 120233AN with two Hg vapor lamps, obtained from RPC Industries (Plainfield, IL)) at a speed of 15.2 m / min (50 ft / min) under a nitrogen atmosphere. The cured microstructured film, having the arrangement pattern shown in Figure 3, was removed from the copper template by gently pulling it off at a 90° angle. An adhesive layer (8 mil thick, obtained as 3M 8188 Optically Clear Adhesive from 3M Corporation) backed with a release liner was applied to the back surface (i.e., the non-microstructured surface) of the microstructured film using a hand roller. The characteristics of the prepared linear prism microstructured film are reported in Table 1. [Table 4]

[0188] Comparative Example A film was prepared using the same procedure as above, except that a copper button with a smooth surface for contact with the resin was used instead of a patterned microstructured surface. This resulted in the formation of a film with a smooth surface (i.e., a film without a patterned microstructured surface).

[0189] Preparation of sample disk Individual discs were cut from the microstructured film using a 34 mm diameter hollow punch. One disc was placed in each well of a sterile 6-well microplate, oriented so that the microstructured surface of the disc faced the well opening and the release liner faced the bottom of the well. The plate was then disinfected and dried by spraying it with a mist of isopropyl alcohol. Discs were also prepared from the film of Comparative Example A.

[0190] Sample disc inoculation, incubation, and washing method Inoculum (4 mL) of the bacterial culture (described above) was added to each well of a 6-well microplate containing a disc. The lid was placed on the 6-well microplate, and the plate was wrapped in PARAFILM M laboratory film (obtained from Bemis Company (Oshkosh, WI)). The wrapped plate was placed in a plastic bag containing a damp paper towel, and the sealed bag was placed in a 37°C incubator. After 7 hours, the plate was removed from the incubator, and the liquid medium was removed from each well using a pipette. Fresh sterile TSB (4 mL) was added to each well, and the plate lid was attached. The plate was wrapped again in PARAFILM M laboratory film, sealed in a bag with a damp paper towel, and returned to the incubator. After 17 hours, the plate was removed from the incubator. The liquid medium was removed from each well (using a pipette) and replaced with 4 mL of sterile deionized water. This water was removed, and the medium was replaced two more times with 4 mL each of sterile deionized water. The last of the water was removed from each well, and then the discs were removed. The liner layer was peeled off each disc to expose the adhesive backing. A hollow punch was used to cut out small 12.7 mm diameter discs from each disc. Some of the discs (n=3) were analyzed for the colony count (cfu) on the disc, and some of the discs (n=3) were advanced to the washing procedure.

[0191] Sample disk cleaning procedure A A 12.7 mm diameter disc was mounted in the washing lane of an Elcometer Model 1720 Abrasion and Washability Tester (Elcometer Incorporated (Warren, MI)) via the disc's adhesive backing. Unless otherwise specified, each disc was positioned in the tester so that the microstructured channels on the disc surface were oriented in the same direction as the movement of the washing carriage. A 2-inch x 5-inch (5.08 cm x 12.7 cm) piece of nonwoven fabric [selected from either SONTARA 8000 or polypropylene nonwoven fabric (fiber diameter 5.9 microns, 40 gsm)] was immersed in a solution containing TWEEN 20 (0.05%) in deionized water, and excess liquid was squeezed out. This nonwoven fabric was secured around a Universal Material Clamp Tool (450 g), which was then mounted on the instrument's carriage. The instrument was set to operate at a speed of 60 cycles / min for 15 carriage cycles (total washing time = 15 seconds).

[0192] Sample disk cleaning procedure B A 12.7 mm diameter disc was mounted in the washing lane of an Elcometer Model 1720 Abrasion and Washability Tester via the disc's adhesive backing. Unless otherwise specified, each disc was positioned within the tester so that the microstructured channels on the disc surface were oriented in the same direction as the movement of the washing carriage. A tool was prepared by additive manufacturing to hold the head of an Acclean manual toothbrush (average bristle diameter approximately 180 microns, obtained from Henry Schein Incorporated (Melville, NY)) within the device's carriage. The toothbrush head and disc were positioned so that the entire exposed surface of the disc was in contact with the brush bristles. The brush bristles were immersed in water before operation. The device was set to operate at a speed of 60 cycles / min for 15 carriage cycles (total washing time = 15 seconds). The tool weighed 190 g.

[0193] Sample disk colony counting method B Following the brushing procedure, each disc was washed five times with 1 mL of a solution containing TWEEN 20 (0.05%) in PBS buffer. Each washed disc was individually transferred to a separate 50 mL conical vial containing a solution of TWEEN 20 (0.05%) in PBS buffer (10 mL). Each tube was vortexed continuously for 1 minute, sonicated for 30 seconds using a Misonix Sonicator Ultrasonic Processor XL (Misonix Incorporated (Farmingdale, NY)) (2-second pulses with 0.5-second intervals between pulses, set to level 3), and vortexed for 1 minute. The solutions from each tube were serially diluted with Butterfield buffer (approximately 8 dilutions) to obtain bacterial concentration levels that yielded colony-forming unit (cfu) counts within the counting range of a 3M PETRIFILM Aerobic Count Plate. Aliquots (1 mL) of each diluted sample were plated onto separate 3M PETRIFILM Aerobic Count Plates according to the manufacturer's instructions. The count plates were sealed in an airtight anaerobic box with two BD GasPak EZ pouches (obtained from Becton, Dickinson and Company) and incubated at 37°C for 24 hours. After the incubation period, the number of cfus on each plate was counted using a 3M PETRIFILM Plate Reader. The count values ​​were used to calculate the total number of cfus recovered from the disks. The results are reported as the average cfu count determined for three disks.

[0194] Disks that did not undergo the brushing procedure were analyzed for colony count (cfu) using the same procedure described.

[0195] Example 9 Discs (12.7 mm) from Example 1, Example 2, and Comparative Example A, inoculated with Pseudomonas aeruginosa, were prepared as described in "Sample Disc Inoculation, Incubation, and Washing Method" (above). The discs were washed using SONTARA 8000 as the nonwoven fabric sheet, according to "Sample Disc Washing Procedure A" (above). The washed discs were analyzed according to "Sample Disc Colony Counting Method A" (above). Average log 10 The CFU count was calculated by cleaning the disk. 10 The CFU reduction values ​​are reported in Table 2.

[0196] SEM images of the disks before washing showed that Comparative Example A's disk surface had a large, continuous biofilm, while the disks of Examples 1 and 2 showed isolated aggregates and small groups of cells on the microstructured disk surface. After the washing procedure, small, patchy biofilm aggregates covered the surface of the disk of Comparative Example A, while the disks of Examples 1 and 2 had only small groups of cells and individual cells on the microstructured disk surface. [Table 5]

[0197] Example 10 Discs (12.7 mm) from Examples 3-8 and Comparative Example A, inoculated with Pseudomonas aeruginosa, were prepared as described in "Sample Disc Inoculation, Incubation, and Washing Method". The discs were washed using SONTARA 8000 as the nonwoven fabric sheet, according to "Sample Disc Washing Procedure A". The washed discs were analyzed according to "Sample Disc Colony Counting Method A". Average log 10 The CFU count was calculated by cleaning the disk. 10 The CFU reduction values ​​are reported in Table 3. [Table 6]

[0198] Example 11 Discs (12.7 mm) from Examples 1, 2, and Comparative Example A, inoculated with Staphylococcus aureus, were prepared as described in "Sample Disc Inoculation, Incubation, and Washing Method". The discs were washed using SONTARA 8000 as the nonwoven fabric sheet according to "Sample Disc Washing Procedure A". The washed discs were analyzed according to "Sample Disc Colony Counting Method A". Average log 10 The CFU count was calculated by cleaning the disk. 10 The CFU reduction values ​​are reported in Table 4.

[0199] SEM images of the disks before washing showed a large, continuous biofilm on the surface of the disk in Comparative Example A, while the disks in Examples 1 and 2 showed isolated aggregates and small groups of cells on their surface. In the case of the disks in Examples 1 and 2, Staphylococcus aureus cells were mainly located in the valleys of the structured surface. After the washing procedure, small, patchy biofilm aggregates covered the surface of the disk in Comparative Example A, while the disks in Examples 1 and 2 had only small groups of cells and individual cells on their surface. [Table 7]

[0200] Example 12 The discs (12.7 mm) of Example 1, Example 2, and Comparative Example A, inoculated with Pseudomonas aeruginosa, were prepared as described in "Sample Disc Inoculation, Incubation, and Washing Method" (above). The discs were washed using a SONTARA 8000 nonwoven fabric sheet according to "Sample Disc Washing Procedure A". The only exception was that half of the discs were oriented in the apparatus so that the microstructured channels on the disc surface were aligned in the same direction as the movement of the washing carriage, and the other half were oriented so that the microstructured channels on the disc surface were aligned perpendicular to the movement of the washing carriage. The washed discs were analyzed according to "Sample Disc Colony Counting Method A". Average log 10 The CFU count was calculated by cleaning the disk. 10 The CFU reduction values ​​are reported in Table 5. [Table 8]

[0201] Example 13 Discs (12.7 mm) from Example 1 and Comparative Example A, inoculated with Pseudomonas aeruginosa, were prepared as described in "Sample Disc Inoculation, Incubation, and Washing Method". The discs were washed using a polypropylene nonwoven fabric sheet (fiber diameter 5.9 microns, 40 gsm) according to "Sample Disc Washing Procedure A". The washed discs were analyzed according to "Sample Disc Colony Counting Method A". Average log 10 The CFU count was calculated by cleaning the disk. 10 The CFU reduction values ​​are reported in Table 6. [Table 9]

[0202] Example 14 Discs (12.7 mm) from Examples 1, 2, and Comparative Example A, inoculated with Streptococcus mutans, were prepared as described in "Sample Disc Inoculation, Incubation, and Washing Method". The discs were washed according to "Sample Disc Washing Procedure B". The washed discs were analyzed according to "Sample Disc Colony Counting Method B". Average log 10 The CFU count was calculated by cleaning the disk. 10 The CFU reduction values ​​are reported in Table 7.

[0203] SEM images of the disks before washing showed a large, continuous biofilm on the surface of the disk in Comparative Example A, while the disks in Examples 1 and 2 showed isolated aggregates of cells that had grown primarily on the upper parts of the microstructured surface. After the washing procedure, the biofilm aggregates still covered most of the surface of the disk in Comparative Example A, while the disks in Examples 1 and 2 had only small groups of cells and individual cells that had grown on the upper parts of the microstructured surface. [Table 10]

[0204] Example 15: Cleaning of sample disc with disinfectant solution The disinfectant cleaning solution was prepared by diluting 3M Disinfectant Cleaner RCT Concentrate 40A (obtained from 3M Corporation) with sterile water (1:256). The discs (12.7 mm) of Example 1, Example 2, and Comparative Example A, inoculated with Pseudomonas aeruginosa, were prepared as described in "Sample Disc Inoculation, Incubation, and Cleaning Method". The peel-off liner layer was removed, and each disc was mounted on the wall of a separate 50 mL conical vial (i.e., one disc per tube). To ensure complete immersion of the discs in the disinfectant cleaning solution, the discs were mounted as close as possible to the bottom of the tubes. An aliquot (4 mL) of the disinfectant cleaning solution was added to each tube, and the tubes were kept at room temperature for 30 seconds or 3 minutes. Dey / Engley neutralizing broth (36 mL) was immediately added, and the samples were mixed by inverting the capped tubes three times by hand. Each tube was vortexed continuously for 30 seconds, sonicated for 30 seconds using a Branson 2510 Ultrasonic Cleaning Bath, and vortexed for 30 seconds. The solution from each tube was serially diluted with Butterfield buffer (approximately 8 dilutions) to obtain bacterial concentration levels that yielded colony-forming unit (cfu) counts within the count range of a 3M PETRIFILM Aerobic Count Plate. Aliquots (1 mL) of each diluted sample were plated onto separate 3M PETRIFILM Aerobic Count Plates according to the manufacturer's instructions. The count plates were incubated at 37°C for 48 hours. After 24 hours of incubation, the number of cfus on each plate was counted using a 3M PETRIFILM Plate Reader. The count values ​​were used to calculate the total number of cfus recovered from disk.

[0205] Control discs were prepared and analyzed using the same procedure, except that the discs were not treated with a disinfectant cleaning solution. The results were compared with the mean log count observed in the control discs (n=3), compared to the mean log count when disinfectant was used. 10 The CFU reduction values ​​are reported in Table 8. [Table 11]

[0206] Example 16 Acrylic pressure-sensitive adhesive (PSA) films were prepared by mixing isooctyl acrylate (450 g, Sigma-Aldrich Company), acrylic acid (50 g, Alfa Aesar (Haverhill, MA)), and DAROCUR 1173 photoinitiator (0.15 g) in a clear glass bottle. The samples were purged with nitrogen for 5 minutes and exposed to low-intensity (0.3 mW / cm²) UV light from 360 nm until a viscosity of approximately 2000 centimeters was achieved. 2 The samples were exposed to UV irradiation. Viscosity measurements were taken at 23°C and 50s. -1 The shear rate was determined using a Brookfield LVDV-II+ Pro Viscometer equipped with an LV Spindle #63 (AMETEK Brookfield (Middleboro, MA)). IRGACURE-651 photoinitiator (1.125 g) and hexanediol diacrylate (2.7 g, Sigma-Aldrich Company) were added to a vial and the mixture was mixed for 24 hours. The resulting viscous polymer solution was coated between silicone-treated polyester release liners (RF02N and RF22N, obtained from SKC Haas (Seoul, Korea)) using a knife coater with a set gap to obtain an adhesive coating thickness of 100 microns. This structure was subjected to a total dose of 1200 mJ / cm². 2 The final PSA film was prepared by irradiating with 350nm UV radiation using UVA radiation.

[0207] The PSA film was applied to the back surface (i.e., the non-microstructured surface) of a linear prism film sheet having the microstructured features of Example 1 (Table 1). The resulting laminated film was cut into test strips [1 inch × 3 inch (2.54 cm × 7.62 cm)]. The test strips were applied to flat glass and polypropylene panels using a hand roller. The panels were conditioned at 120°C for 4 hours and then equilibrated to room temperature. The test strips were peeled off the panel surfaces by hand. Following the removal of the test strips, the panel surfaces were visually inspected, and no residue of the test strips was observed on any of the panel surfaces. This PSA-coated microstructured film can be adhered to the surface of medical diagnostic devices such as stethoscope diaphragms.

[0208] Example 17 A linear prism film, as shown in Figure 3, with the dimensions of Example 3, was prepared using a metal tool with a laminator. A layer of 3M Tape Primer 94 (available from 3M Corporation) was applied to the center (12cm x 13cm) of one side of a VIVAK PET-G sheet (30cm x 30cm, sheet thickness = 2.1mm) using a brush. The primer layer was then allowed to dry at room temperature for 5 minutes. A second primer layer was applied in the same manner and subsequently dried. UV-curable resin (above) was applied to the tool with a pipette, and the PET-G disc was placed over the tool, with the primer-treated surface of the disc facing the tool and the tool positioned in the center of the sheet. The disc was laminated using a laminator with a nip pressure setting of 50 psig and a speed setting of 0.52 feet / min (0.16 meters / min). The sample was cured with UV light by passing it three times through a UV processor (model QC 120233AN with two Hg vapor lamps, obtained from RPC Industries) at a speed of 15.2 meters / min (50 feet / min) under a nitrogen atmosphere.

[0209] The resulting laminated microstructured film sheet was thermoformed using a Model C22-S MAAC Thermoformar (MAAC Machines (Carol Stream, IL)). The template model consisted of two hand wrenches placed side by side. One wrench was an adjustable crescent wrench (110 mm in length), and the other was a 7 / 16-inch combination wrench (open end and box end) with a total length of 125 mm. The sheet was placed in the holder, and the thermoforming cycle was started with an immersion time of 100-110 seconds, top and bottom heater power of 55%, and vacuum of 30 mmHg. The sheet was oriented so that the microstructured portion of the sheet was aligned with the wrench template, with the microstructured surface facing away from the wrench template. The sheet was conformally formed with high fidelity to cover the wrench. The thermoformed thermoplastic article was separated from the template, and the microstructure of the article was inspected and measured using a Keyence VK-X 200 series laser microscope (Keyence Corporation). The microstructures retained nominal 60% of their shape and peak height. This example demonstrates that thermoforming microstructured sheets or films can be used as a method for manufacturing components of medical diagnostic devices, such as ultrasound probe caps.

[0210] Example 18 A UV-curable resin was prepared from PHOTOMER 6210 aliphatic urethane diacrylate oligomer (75 parts), SR238 1,6-hexanediol diacrylate (25 parts), and LUCIRIN TPO photoinitiator (0.5%). The components were blended in a high-speed mixer and heated in an oven at approximately 70°C for 24 hours, then cooled to room temperature. A copper button was used as a template for preparing a cube corner microstructured film. Both the button and the resin mixture were heated in an oven at approximately 70°C for 15 minutes. The heated resin was applied to the center of the heated button using a transfer pipette. A piece of MELINEX 618 PET support film (5 mil thickness), larger than the button, was placed to cover the applied resin, followed by a glass plate. The primer-treated surface of the PET film was oriented to contact the resin. The glass plate was held in place by hand until the resin completely covered the surface of the button. The glass plate was carefully removed. If air bubbles were present, they were removed using a rubber hand roller.

[0211] The sample was cured with UV light by passing it twice through a UV processor (model QC 120233AN with two Hg vapor lamps, obtained from RPC Industries (Plainfield, IL)) at a speed of 15.2 m / min (50 ft / min) under a nitrogen atmosphere. The cured microstructured film was removed from the copper template by gently pulling it away at a 90° angle. The microstructured surface had an arrangement of inclined cube corner structures as shown in Figure 4A. Referring to Figure 4C, the dimensions of the individual cube corner microstructures were as follows: triangular base, 70 / 55 / 55 degrees (beta 1, 2, 3); side wall angles alpha 2, alpha 3, and alpha 1, 60, 60, and 89 degrees, respectively; peak height, 63.3 micrometers; valley width, 127 micrometers and 145 micrometers. The copper button used as the template had a negative copy of this microstructured surface.

[0212] Example 19 Using compression molding, sheets of G-10 epoxy laminate were prepared, having a linear prism microstructured surface with the same microstructured feature dimensions as reported for Example 1. A mold with a negative copy of the microstructured surface was fabricated from a master using 3M ESPE PARADIGM Heavy Body VPS impression material (3M Corporation). The mold (15.2 cm × 15.2 cm) was placed on a flat piece of cardboard. Two sheets of G10 Epoxy Fiberboard (12.7 cm × 12.7 cm) were stacked and placed in the center of the mold. A flat, smooth sheet of silicone (approximately 1.27 cm) was placed on top of the epoxy sheets, and a flat stainless steel plate (approximately 2.54 cm thick) was placed on top of the silicone sheet. The completed laminate was placed on the lower platen of a hydraulic press. The upper and lower platens of the press were heated to 300°F (148.9°C), and the laminate was subjected to a pressure of 2500 pounds (100 pounds per square inch) for 1 hour. The platens were then cooled to 70°F (21.1°C) while maintaining the pressure on the laminate. After cooling, the applied pressure was removed. The resulting microstructured G-10 epoxy sheet was removed from the mold and silicone spacer.

[0213] Example 20 Using compression molding, sheets of G-10 epoxy laminate with a cube corner microstructured surface were prepared according to the procedure reported in Example 19. A mold having a negative mold replica of the microstructured surface described in Example 18 was fabricated from a master using 3M ESPE PARADIGM Heavy Body VPS impression material.

[0214] Example 21 Sheets of G-10 epoxy laminate with a cube-corner microstructured surface were prepared using compression molding with metal tools.

[0215] The silicon-containing layer was applied to the microstructured surface of the tool using a parallel-plate capacitive-coupled plasma reactor, as described in International Publication No. 2009 / 032815 (David). The reactor chamber was 3.61 ft.2 (0.10m 3 It had a central cylindrical power supply electrode with a surface area of ​​). The microstructuring tool was placed on the chamber floor directly below the power supply electrode (nominal distance between the tool and electrode approximately 4 inches (10.16 cm)), and the reactor chamber was pumped down to a base pressure of less than 1.3 Pa (1 mTorr). Oxygen was introduced into the chamber at a flow rate of 600 SCCM (standard cubic centimeters per minute). The process was carried out by coupling RF power to the reactor at a frequency of 13.56 MHz and an applied power of 600 watts for 60 seconds. The second step of depositing a thin film on the microstructure was achieved by stopping the oxygen flow and evaporating HMDSO (hexamethyldisiloxane) and transporting it into the system at a flow rate of 120 SCCM. The process was carried out using plasma-enhanced chemical vapor deposition (CVD) by coupling RF power to the reactor at a frequency of 13.56 MHz and an applied power of 600 watts for 120 seconds. After the completion of the second step, in addition to the 120 SCCM flow of HMDSO, a second line of HMDSO was opened to the chamber. The combined flow rate resulted in a chamber pressure of 4.1 mTorr. The treatment was carried out by coupling RF power to the reactor at a frequency of 13.56 MHz and an applied power of 200 watts for 45 seconds. The process conditions resulted in a peeled coating with an estimated thickness of less than 200 nm. After each step, after the described gas flow had stabilized, RF power was applied to the electrodes to generate plasma. Following the completion of the plasma treatment, the RF power and gas supply were stopped, and the chamber was returned to atmospheric pressure.

[0216] A metal tool (15.2 cm x 15.2 cm) was placed on a flat piece of cardboard. Two sheets of G10 Epoxy Fiberboard (12.7 cm x 12.7 cm) were stacked and placed in the center of the mold. A flat, smooth sheet of silicone (approximately 1.27 cm thick) was placed on top of the epoxy sheets, and a flat stainless steel plate (2.54 cm thick) was placed on top of the silicone sheet. The completed laminate was placed on the lower platen of a hydraulic press. The upper and lower platens of the press were heated to 300°F (148.9°C), and the laminate was subjected to a pressure of 2500 lbs (100 lbs per square inch) for 1 hour, after which the platen was cooled to 70°F (21.1°C) while maintaining the pressure on the laminate. After cooling, the applied pressure was removed. The resulting microstructured G-10 epoxy sheet was removed from the mold and silicone spacer. The microstructured surface had an arrangement of inclined cube corner structures as shown in Figure 4A. Referring to Figure 4C, the dimensions of the individual cube corner microstructures were as follows: triangular base angles of 58 / 58 / 64 degrees (beta 1, 2, 3); side wall angles of 67, 67, and 77 degrees, respectively; peak height of 49.5 micrometers; and valley widths of 101.6 micrometers and 107.7 micrometers.

[0217] Comparative example B A flat, smooth sheet of the G-10 epoxy laminate was fed into the same compression molding process as described in Example 19, except that the micro-element mold was replaced with a second flat, smooth silicone sheet in the laminate. This resulted in the formation of an epoxy sheet with a smooth surface (i.e., a film without a patterned microstructured surface).

[0218] Example 22 The discs (12.7 mm) from Example 19 and Comparative Example B were prepared, washed, and analyzed according to the procedure described in Example 9. Average log 10 The CFU count was calculated by cleaning the disk. 10 The CFU reduction values ​​are reported in Table 9. [Table 12]

[0219] Example 23: Reduction of microbial contact transfer Tryptic Soy Agar was prepared according to the manufacturer's instructions. Streak plates of Pseudomonas aeruginosa (ATCC 15442) or Staphylococcus aureus (ATCC 6538) were prepared from frozen stocks of Tryptic Soy Agar and incubated overnight at 37°C. Two colonies from the plates were inoculated into 9 mL of sterile Butterfield Buffer (3M Corporation). Optical density (absorbance) was read at 600 nm, and the reading was confirmed to be 0.040 ± 0.010. The culture was adjusted to this range as needed. A portion of the culture (1.5 mL) was added to 45 mL of Butterfield Buffer in a sterile 50 mL conical tube to prepare an inoculum for contact transfer experiments. Serial dilutions of the inoculum were prepared using Butterfield Buffer. The diluted samples were plated onto 3M PETRIFILM Aerobic Count plates (3M Corporation) and evaluated according to the manufacturer's instructions to confirm the cell concentration used in each experiment.

[0220] Microstructured samples (50 mm × 50 mm) for Examples 1, 2, 18, 19, and 20 were prepared and individually attached to the inner bottom surface of sterile 100 mm Petri dishes using double-sided tape. Each Petri dish contained one sample, and the samples were mounted so that the microstructured surface was exposed. The corresponding comparative examples A and B were also tested and served as control samples. The sample from comparative example A served as a control sample for the microstructured samples of Examples 1, 2, and 18. The sample from comparative example B served as a control sample for the microstructured samples of Examples 19 and 20. The exposed surface of each microstructured sample and control sample was wiped three times using a KIMWIPE wiping cloth (Kimberly-Clark Corporation (Irving, TX)) moistened with a 95% isopropyl alcohol solution. The samples were air-dried in a BioSafety Cabinet for 15 minutes with the fan turned on. Next, the samples were sterilized in a cabinet for 30 minutes using UV light irradiation.

[0221] The inoculum (25 mL of either Staphylococcus aureus or Pseudomonas aeruginosa as described above) was poured into a sterile petri dish (100 mm). For each sample, a circular disc of autoclaved Whatman Filter Paper (grade 2, 42.5 mm in diameter; GE Healthcare (Marborough, MA)) was grasped using flame-sterilized tweezers and immersed in the petri dish containing the inoculum for 5 seconds. The paper was removed and held above the dish for 25 seconds to allow excess inoculum to drain from the paper. The inoculated paper disc was placed on top of the microstructured sample, and a new autoclaved Whatman Filter paper piece (grade 2, 60 × 60 mm) was placed over the inoculated paper disc. A sterile Conlarger rod was pressed against the top paper surface of the stack and moved twice vertically across the surface. The stack was held for 2 minutes. Then, using sterile tweezers, both filter paper pieces were removed from the microstructured sample. The sample was air-dried at room temperature for 5 minutes. The contact migration of bacteria from the microstructured surface of each sample was evaluated by evenly pressing an RODAC plate (Trypticase Soy Agar with Lecithin and Polysorbate 80; Thermo Fisher Scientific) onto the film sample under uniform pressure (approximately 300g) for 5 seconds. The RODAC plates were incubated overnight at 37°C. Following the incubation period, colony-forming units (cfus) were counted for each plate. Samples were tested three times, and the average count value was reported.

[0222] Log the average cfu count per RODAC plate. 10 Converted to scale. Log of CFU count due to contact movement. 10 The decrease value is obtained from the log of the corresponding control sample (sample with a smooth surface). 10 Log obtained from the microstructured sample from the count value 10 The determination was made by subtracting the count value. The average decrease in contact movement % (n=3) was calculated using formula A. The results are reported in Table 10. Equation A: Decrease in contact movement % = (1 - 10 (-log 10減少値) )×100

Table 13

[0223] Example 24 Stethoscope with a Microstructured Diaphragm A circular disk (diameter 174 mm, thickness 0.023 mm) was laser cut (CO2 laser) from the microstructured G-10 epoxy laminate sheet prepared in Example 21. Next, the disk was insert molded using a flexible polyurethane rim to form an adult diaphragm component for the 3M LITTMANN Cardiology IV Diagnostic Stethoscope (obtained from 3M Corporation). In the molding process, the microstructured disk was oriented such that the microstructured features were on the surface facing the outside of the diaphragm (i.e., the surface of the diaphragm that contacts the subject's skin during use). The original adult diaphragm was removed from the 3M LITTMANN Cardiology IV Diagnostic Stethoscope and replaced with the microstructured adult diaphragm.

[0224] Comparative Example C. Stethoscope without a Microstructured Diaphragm A circular disk (diameter 174 mm, thickness 0.023 mm) was laser cut (CO2 laser) from the G-10 epoxy laminate sheet prepared in Comparative Example B. Next, the disk was insert molded using a flexible polyurethane rim to form the adult diaphragm of the 3M LITTMANN Cardiology IV Diagnostic Stethoscope. The original adult diaphragm was removed from the 3M LITTMANN Cardiology IV Diagnostic Stethoscope and replaced with the G-10 epoxy laminate diaphragm.

[0225] Example 25 Stethoscope Acoustic Test Apparatus and Procedure The acoustic performance of a stethoscope can be described by its frequency response to a broadband noise source or pink noise source coupled to the chestpiece in a manner that mimics the human torso. The test apparatus used to characterize the acoustic performance of the stethoscope is described in Figure 10 of U.S. Patent No. 10,398,406. This apparatus includes: Bruel & Kjaer Head and Torso Simulator (HATS) types 4128C and 4159C Left Ear Simulator, 4158C Right Ear Simulator, and Calibrated Left and Right pinnae (Bruel & Kjaer North America (Duluth, GA)). The sound source was a loudspeaker housed in a cylindrical acoustic chamber with an 87mm top opening filled with a silicone gel pad measuring 130mm in diameter and 30mm in thickness. The silicone gel pad was used to mimic human skin / flesh and was made from ECOFLEX 00-10 Super Soft Shore 00-10 Platinum Silicone Rubber Compound (Reynolds Advanced Materials (Countryside, IL)). A stethoscope prepared according to Example 24, and a commercially available 3M LITTMANN Cardiology IV Diagnostic stethoscope without modification to the diaphragm were also used. A stethoscope (comparative example) was tested. An adult-sized diaphragm was used, and the stethoscope chestpiece was placed on a gel pad. A 100g weight was applied to the top of the chestpiece to simulate light force. The stethoscope eartips were inserted into the earpieces of a head simulator. A microphone in the ear coupler detected the stethoscope sound in a manner equivalent to that of a human ear, and a reference microphone positioned above the loudspeaker provided a normalized signal of the transfer function frequency response. The transfer function is defined as follows: H1(f) = (Sxy(f)) / (Sxx(f)) In the formula, S xy (f) is the crossspectrum between the HATS ear and the reference microphone, and S xx(f) is the auto-spectrum of the reference microphone.

[0226] The sound was generated, recorded, and characterized using a Bruel&Kjaer (B&K) LAN-XI acoustic test system operated by a PC using B&K PULSE software. An audio amplifier was used to drive a loudspeaker with the sound generated by the LAN-XI system. An acoustic cylinder with a built-in speaker was placed on a 60 cm x 90 cm ISOSTATION Vibration Isolation Workstation (Newport Corporation (Irvine, CA)). Transfer function frequency response (Y-axis in decibels / 1 Pascal / Pascal) curves were generated for each stethoscope over a frequency range of 20 to 2,000 Hz.

[0227] FIG. 13 shows the individual transfer function frequency response curves generated using the stethoscope of Example 24 and the commercially available LITTMANN Cardiology IV Diagnostic Stethoscope (comparative example). Since their response curves were generally the same over the entire frequency range, there was no perceivable difference between these stethoscopes when used for auscultation.

[0228] Example 26 A layer of 3M Tape Primer 94 (obtained from 3M Corporation) was applied to the entire surface of one side of a DURAN PET-G disk (disk diameter = 125 mm, disk thickness = 0.75 mm) using a brush. Then, the primer layer was dried at room temperature for 5 minutes.

[0229] A metal tool was used with a laminator to create a microstructured surface with cube corner features. A UV-curable resin (described above) was applied to the tool using a pipette. The coated tool was placed in a vacuum oven, and the pressure inside the oven was slowly reduced to 635 mmHg. Once this vacuum was achieved, the pressure was increased back to atmospheric pressure. A PET-G disc was placed over the tool, with the primer-treated surface of the disc facing the tool. The disc was laminated using a laminator with a nip pressure setting of 50 psig and a speed setting of 0.52 feet / min (0.16 meters / min). The sample was cured with UV light by passing it three times through a UV processor (model QC 120233AN with two Hg vapor lamps, obtained from RPC Industries) at a speed of 15.2 meters / min (50 feet / min) in a nitrogen atmosphere. The disc was carefully removed from the tool. The microstructured surface had an arrangement of inclined cube corner structures as shown in Figure 4A. Referring to Figure 4C, the dimensions of the individual cube corner microstructures were as follows: triangular base, 70 / 55 / 55 degrees (beta 1, 2, 3); side wall angles alpha 2, alpha 3, and alpha 1, 60, 60, and 89 degrees, respectively; peak height, 63.5 micrometers; valley width, 127 micrometers and 178 micrometers. The metal tool had a negative copy of the microstructured surface.

[0230] The stacked microstructured discs were formed onto dental aligner articles using a BIOSTAR VI pressure molding machine (Scheu-Dental GmbH). The microstructured discs were heated for 30 seconds and then stretched to cover a rigid polymer model. The film was oriented so that the microstructured surface was in contact with the model. The molding machine chamber behind the film was pressurized to 90 psi for 30 seconds while cooling, and then the chamber was vented back to ambient pressure. The model was removed from the molding machine along with the thermoformed film, and the excess film was trimmed using an ultrasonic cutter (model NE80, Nakanishi Incorporated (Kanuma City, Japan)). The completed thermoformed three-dimensional shell was separated from the model. The microstructure of the formed three-dimensional shell was inspected and measured using a Keyence VK-X200 series laser microscope (Keyence Corporation (Itasca, IL)). The cube corner microstructures retained 80% of their shape and nominal peak height. This example demonstrates that thermoforming of cube corner microstructured sheets or films can be used as a method for manufacturing components of medical diagnostic devices, such as ultrasound probe caps.

[0231] Comparative Example D: Rectangular corrugated microstructured film A tool with multiple parallel, straight grooves was cut using a diamond (tip width 29.0 micrometers, angle 3°, depth 87 micrometers). The grooves were spaced 59.1 micrometers apart. Resin A was prepared by mixing the materials listed in Table 11 below. [Table 14]

[0232] A high-definition casting and curing process was carried out using the resin A and tools described above. Line conditions were: resin temperature 150°F (65.5°C), die temperature 150°F (65.5°C), coater IR 120°F (48.9°C) edge / 130°F (54.4°C) center, tool temperature 100°F (37.8°C), and line speed 70 fpm. A Fusion D lamp with a peak wavelength of 385 nm (obtained from Fusion UV Systems (Gaithersburg, MD)) was used for curing and operated at 100% power. The resulting microstructured film had multiple walls separated by channels, as shown in Figure 2. The base layer was a PET film (3M Corporation) with a thickness of 3 mil (76.2 micrometers). The side of the PET film in contact with the resin was primed with a thermosetting acrylic polymer (Rhoplex 3208, obtained from Dow Chemical (Midland, MI)). The land layer of the cured resin had a thickness of 8 micrometers. Referring to Figure 2, the dimensions of the surface of the resulting microstructured film were as follows: wall height (H) 84.1 micrometers, side wall angle 0.4 degrees, pitch 59.1 micrometers, width of the top surface of the wall 28.5 micrometers, and maximum valley width 30.6 micrometers.

[0233] The discs (12.7 mm) of Comparative Example D and Comparative Example A were prepared, washed, and analyzed according to the procedure described in Example 9. Average log 10 The CFU count was calculated by cleaning the disk. 10 The CFU reduction values ​​are reported in Table 12. [Table 15]

[0234] Comparative Examples E and F: Rectangular corrugated microstructured film Two rectangular corrugated microstructured films with different dimensions were produced according to the procedure described in Comparative Example D. The microstructured film of Comparative Example E had the following surface dimensions: wall height (H) 89.5 micrometers, side wall angle 1.4 degrees, pitch 62.3 micrometers, wall top width 28.8 micrometers, and maximum valley width 33.3 micrometers. The microstructured film of Comparative Example F had the following surface dimensions: wall height (H) 45 micrometers, side wall angle 0.48 degrees, pitch 30 micrometers, wall top width 15 micrometers, and maximum valley width 15 micrometers.

[0235] Samples of the microstructured film were evaluated for reduction in microbial contact transfer according to the procedure described in Example 23 (using Staphylococcus aureus). The average reduction in microbial contact transfer for the microstructured film of Comparative Example E was 25-37%. The microstructured film of Comparative Example F showed an average increase of 10% in microbial contact transfer compared to the corresponding control sample.

[0236] Example 27 Surface coverage of liquid disinfectant Samples of the microstructured films from Example 1, Example 20, and Comparative Example A (7.6 cm × 20.3 cm strips) were attached to the washing lane of the Elcometer Model 1720 Abrasion and Washability Tester (ELCOMETER Incorporated). Furthermore, a cube corner microstructured film (Example 27a) was prepared according to Example 20 so that each cube corner microstructure had the following dimensions: triangular base of 60 / 60 / 60 degrees (beta 1, 2, 3); side wall angles alpha 2, alpha 3, alpha 1 of 45, 45, 45 degrees; peak height of 9 micrometers; valley width of 27.7 micrometers and 27.7 micrometers. The corresponding sample strips from Example 27a were also attached to the washing lane of the apparatus. Each lane contained one test sample. For the microstructured samples, the microstructured surface was exposed with the opposite non-microstructured surface attached to the washing lane. For the microstructured film of Example 1, some samples were placed in the apparatus so that the microstructured channels on the film surface were oriented in the same direction as the carriage movement (parallel direction), while the other samples were placed in the apparatus so that the microstructured channels on the film surface were oriented perpendicular to the carriage movement.

[0237] Two different dampened cloths were used in the experiment. The first dampened cloth was a 5.1cm x 12.7cm piece of SONTARA 8000 nonwoven fabric immersed in an aqueous solution of 70% isopropyl alcohol containing 0.025% crystal violet dye (obtained from Sigma-Aldrich Company). The second dampened cloth was a paper towel (a 5.1cm x 12.7cm piece of WypALL L30 General Purpose Wiper obtained from Kimberly-Clark Corporation (Irving, TX)) immersed in a 70% isopropyl alcohol solution containing 0.025% crystal violet dye. Excess liquid was removed from all cloths by squeezing them by hand. Each dampened cloth was secured around a Universal Material Clamp Tool (450g), which was then mounted on the apparatus carriage. The device was set to operate at a speed of 60 cycles / minute with 15 carriage cycles (total time = 15 seconds).

[0238] After the test was completed, images of the surface of each sample were taken at 1 minute and 3 minutes, and the coverage rate of the dye on the sample surface was determined. The color images were converted to 8-bit, and three randomly selected 200x200 pixel regions of each image were analyzed. A threshold was set, and the percentage of surface area covered by the dye was measured using the open-source image processing software ImageJ (NIH, Bethesda, MD, https: / / imagej.nih.gov / ij / ). The results are reported in Tables 13 and 14 as the percentage of the test sample surface covered by the dye. Here, 100% represents complete coverage of the test sample surface by the dye. The reported values ​​are the average values ​​calculated from the three analysis regions. [Table 16] [Table 17]

[0239] Example 28 Surface Coverage Rate of Liquid Disinfectant The same procedure as reported in Example 27 was followed, except that another disinfectant solution was used to prepare the moistened wiping cloth. The disinfectant solution was a diluted aqueous solution (1:256) of 3M Disinfectant Cleaner RCT Concentrate 40A (a quaternary ammonium-based cleaning agent) containing 0.025% crystal violet dye. The first moistened wiping cloth was a SONTARA 8000 non-woven fabric (5.1 cm × 12.7 cm) immersed in the disinfectant solution. The second moistened wiping cloth was a paper towel (a 5.1 cm × 12.7 cm piece of WypALL L30 General Purpose Wiper) immersed in the disinfectant solution. Excess liquid was removed from all the wiping cloths by wringing the liquid out by hand. The results are reported in Tables 15 and 16.

Table 18

Table 19

[0240] Example 29 Three different linear prism microstructured films with various dimensions were prepared according to the procedure described for Example 1. The dimensions of the three films are reported in Table 17. Samples of those three films, together with the samples of Example 1 and Comparative Example A, were evaluated according to the procedure described in Example 9. All the microstructured films showed a log cfu count reduction that was approximately 1.5 log greater than that observed for Comparative Example A. 10 cfu count reduction was shown.

Table 20

[0241] Example 30 Discs (12.7 mm) from Examples 1, 2, and Comparative Example A, inoculated with Pseudomonas aeruginosa, were prepared as described in the method "Sample Disc Inoculation, Incubation, and Washing Method with Final Drying Step" (above). The discs were washed using SONTARA 8000 as the nonwoven fabric sheet according to "Sample Disc Washing Procedure A" (above). The washed discs were analyzed according to "Sample Disc Colony Counting Method A" (above). Average log 10 The CFU count was calculated by cleaning the disk. 10 The CFU reduction values ​​are reported in Table 18. [Table 21]

Claims

1. A medical diagnostic device or component thereof, comprising a microstructured surface including peak structures and adjacent valleys, said valleys having a maximum width in the range of 1 to 1000 microns.

2. 10. The device of claim 1, wherein a sensor of the medical diagnostic device includes the microstructured surface, the sensor having acoustic diagnostic properties substantially equivalent to a similar medical diagnostic device or component thereof lacking the microstructured surface.

3. 3. The device of claim 1 or 2, wherein the sensor is a stethoscope diaphragm, the stethoscope diaphragm having a transfer function frequency response curve over a frequency range of 20 to 2000 hertz that is substantially equivalent to a similar diaphragm lacking the microstructured surface.

4. The device of claim 3 , wherein a stethoscope tube and / or an ear tip further comprises the microstructured surface.

5. 5. The device of any one of claims 1 to 4, wherein the microstructured surface is integral with the medical diagnostic device or a component thereof, or the microstructured surface is disposed on a film, and the film is bonded to the medical diagnostic device or a component thereof.

6. 6. The device of any one of claims 1 to 5, wherein the microstructured surface provides at least a 25, 30, 35, 40, 45, 50, 60, 70, 80, 90, 95, or 99% reduction in contact transfer of microorganisms.

7. A device according to any one of claims 1 to 6, wherein the facets form a continuous or semi-continuous surface in the same direction and the valleys have no intersecting walls.

8. 8. The device of claim 1, wherein the microstructured surface does not include any flat surface area that is parallel to the planar base layer, or has less than 50, 40, 30, 20, or 10% flat surface area that is parallel to the planar base layer.

9. The device of any one of claims 1 to 8, wherein the microstructured surface provides a log 10 reduction in microorganisms (e.g., bacteria) of at least 2, 3, 4, 5, 6, 7, or 8 after cleaning.

10. The device of claim 1 , wherein the microstructured surface comprises a linear array of prisms or an array of cube corner elements.

11. The device of any one of claims 1 to 10, wherein the peak structures have sharp, rounded or truncated peaks and have apex angles in the range of 20 to 120 degrees.

12. 12. The device of any one of claims 1 to 11, wherein at least 50, 60, 70, 80, 90% of the microstructured surface contains the cleaning solution 1 to 3 minutes after the cleaning solution is applied to the microstructured surface.

13. The device of any one of claims 1 to 12, wherein the microstructured surface has an Sbi / Svi that is greater than 3 and less than 90.

14. The device of any one of claims 1 to 13, wherein the microstructured surface does not comprise a fluorinated material or a polydimethylsiloxane material.

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