WO2023079511A1

WO2023079511A1 - Method of aligning and sealing articles and fluidic devices with sealed parts

Info

Publication number: WO2023079511A1
Application number: PCT/IB2022/060647
Authority: WO
Inventors: Gal Ingber
Original assignee: Pocared Diagnostics Ltd
Priority date: 2021-11-05
Filing date: 2022-11-04
Publication date: 2023-05-11

Abstract

A method of welding a side of a first element to a side of a second element is provided. The side of the first element includes a recessed surface and a protruding surface. The side of the second element includes a recessed surface and a protruding surface. A rib extends from the first element, optionally from the recessed surface of the first element, or from the second element, optionally from the protruding surface of the second element. The method includes a step of moving the first element towards the second element, thereby causing a surface of the rib to contact the first element or the second element. The method also includes, with the rib in contact with the first element or the second element, as step of melting the rib, thereby causing the protruding surface of the first element to contact the recessed surface of the second element.

Description

METHOD OF ALIGNING AND SEALING ARTICLES AND FLUIDIC DEVICES WITH SEALED PARTS

CROSS REFERENCE TO RELATED APPLICATION

[0001] The present application claims the benefit of U.S. Provisional Patent Appl. No. 63/276,232, filed November 5, 2021, the disclosure of which is hereby incorporated by reference in its entirety.

BACKGROUND OF THE INVENTION

Field of the Invention

[0002] The present disclosure is directed to methods for accurately and precisely aligning articles or parts in plastic manufacturing processes and, in particular, to alignment methods used for thermoplastic, laser, and/or ultrasonic welding processes for connecting parts with discontinuous surfaces and/or surfaces of different heights and for forming sealed fluidic channels and reservoirs within fluidic articles and devices.

Description of Related Art

[0003] Fluidic and microfluidic articles and devices include reservoirs and fluid channels for containing and transporting fluids through an interior of the articles and devices. Such fluidic and microfluidic devices can be made using precision molding and manufacturing techniques to create parts having complexly shaped reservoirs and fluid channels. However, production of precision articles with defined surfaces and tolerances by common heat- welding techniques can result in gaps and spaces. In fact, in some examples, gaps and spaces can be engineered into the article to account, for example, for expansion, deformation, or other changes to the plastic material that can occur during processing and manufacturing.

[0004] Gaps and spaces can also be designed into molded parts so that parts with discontinuous surfaces or surfaces of different heights can be joined together by welding. For example, as described in further detail herein, a first molded part and a second molded part, with uneven or discontinuous surfaces, can be designed to be welded together. It can be conventional to design the molded parts so that gaps or spaces are present between some of the surfaces of the first part and the second part so that the parts can be manufactured to a less tight tolerance. By contrast, if welding joints were needed or intended to be formed between all areas of contact between the first part and the second part, the molded parts would need to be manufactured to a tighter tolerance to ensure that the different surfaces were correctly positioned for welding. [0005] Traditionally, liquid egress or ingress through these designed spaces or gaps is controlled, restricted, or prevented by attaching elastomeric seals or gaskets, such as seals and gaskets formed from rubber (e.g., synthetic or natural isoprene) or silicone, over or around connection points or joints between parts of the article or device to ensure that the parts are joined together in a leak-free connection. However, placement of the gaskets or seals in the article or device adds cost and complexity to manufacturing processes. Also, elastomeric materials can leach contaminates into liquids in contact with the elastomeric materials. Leached elastomeric materials can interfere with and affect accuracy of results obtained using various analytic methods and devices. For example, contaminates may interfere with analysis of a biological sample, such as urine, blood, plasma, serum, saliva, cell culture, cell suspension or dilution, or other liquid samples, meaning that elastomeric seals and gaskets may not be suitable for use in devices that obtain and analyze biological samples.

[0006] Precision articles can be manufactured with different plastic parts joined together without separate seals or gaskets. However, without sufficient internal seals, dead volumes can be formed in complexly shaped articles. Portions of a liquid sample can enter or can be drawn into (e.g. by capillary action) the dead volumes leading to sample loss. In order to address sample loss due to internal dead volumes, extra sample can be collected to ensure that a sufficient volume of sample is available for any analytic techniques to be performed for the collected samples. However, needing to acquire additional liquid may interfere with some analysis techniques, such as spectrophotometric or electro-conductive sample analysis. Also, concentrations of samples being tested may be skewed if only certain constituents of the liquid sample favorably egress into the dead volume, gaps, or spaces, while other constituents of a sample do not enter the gaps or spaces. Accordingly, unsealed dead volumes in fluidic devices can be a source of error for biological sample assays in some cases.

[0007] For these reasons, there is a need in the art for manufacturing techniques for precisely aligning and sealing parts or components of fluidic articles and devices together without using elastomeric seals or gaskets, which can contaminate biological samples. Also, the manufacturing techniques should reduce or eliminate gaps, spaces, and dead volumes so that sample loss is avoided. The methods, articles, and devices disclosed herein are provided to address these issues.

SUMMARY OF THE INVENTION

[0008] According to an aspect of the disclosure, a method of welding a side of a first element to a side of a second element is provided. The side of the first element includes a recessed surface and a protruding surface. The side of the second element includes a recessed surface and a protruding surface. At least one rib extends from the first element, optionally from the recessed surface of the first element, or from the second element, optionally from the protruding surface of the second element. The method includes a step of moving the first element towards the second element, thereby causing a surface of the at least one rib to contact the first element or the second element. The method also includes, with the at least one rib in contact with the first element or the second element, as step of melting the rib, thereby causing the protruding surface of the first element to contact the recessed surface of the second element.

[0009] According to another aspect of the disclosure, a cassette for containing a fluid biological sample includes at least one upper cover element having an outwardly facing side and an inwardly facing side. The inwardly facing side includes a protruding surface and a recessed surface. The cassette also includes a body having a first side mounted to the at least one upper cover element including a recessed surface and a protruding surface. The cassette further includes at least one partially melted rib extending from the at least one upper cover element, optionally from the recessed surface of the at least one upper cover element, or from the first side of the body, optionally from the protruding surface of the first side of the body. The partially melted rib joins the first side of the body to the at least one upper cover element. At least a portion of the protruding surface of the at least one upper cover element is joined to at least a portion of the recessed surface of the first side of the body by a welded joint.

BRIEF DESCRIPTION OF THE DRAWINGS

[0010] FIG. 1 is a schematic drawing showing a conventional technique for attaching a first plate to a second plate, as known in the prior art;

[0011] FIG. 2A is a schematic drawing showing a method for attaching a first plate to a second plate by a positioning and alignment method, according to an aspect of the present disclosure;

[0012] FIG. 2B is a schematic drawing showing the first plate connected to the second plate by the positioning and alignment method of the present disclosure;

[0013] FIG. 3A is a perspective view of a fluidic cassette including reservoirs formed by the positioning and alignment method of the present disclosure;

[0014] FIG. 3B is a front view of the fluidic cassette of FIG. 3A;

[0015] FIG. 3C is a rear view of the fluidic cassette of FIG. 3A;

[0016] FIG. 4A is a cross-sectional view of the fluidic cassette of FIG. 3A taken along line

4A-4A in FIG. 3B; [0017] FIG. 4B is a perspective view of a cross-section of the fluidic cassette of FIG. 3A taken along line 4B-4B;

[0018] FIG. 4C is an enlarged view of a portion of the cross-section of FIG. 4A showing an interface between plates of the cassette that form a fluid reservoir of the cassette; and

[0019] FIG. 5 is an enlarged view of a portion of a cross-section of another fluidic cassette showing an interface between plates forming a reservoir, as is known in the prior art.

DESCRIPTION OF THE INVENTION

[0020] As used herein, the singular form of “a”, “an”, and “the” include plural referents unless the context clearly states otherwise.

[0021] As used herein, the terms “right”, “left”, “top”, “bottom”, and derivatives thereof shall relate to the invention as it is oriented in the drawing figures. However, it is to be understood that the invention can assume various alternative orientations and, accordingly, such terms are not to be considered as limiting. Also, it is to be understood that the invention can assume various alternative variations and stage sequences, except where expressly specified to the contrary. It is also to be understood that the specific devices and processes illustrated in the attached drawings, and described in the following specification, are examples. Further, depicted elements are not necessarily to scale, but are depicted in a manner to facilitate the showing of any described element and its relation to other elements of a described device. Hence, specific dimensions and other physical characteristics related to the embodiments disclosed herein are not to be considered as limiting.

[0022] For the purposes of this specification, unless otherwise indicated, all numbers expressing, for example, dimensions, physical characteristics, and so forth used in the specification and claims are to be understood as being modified in all instances by the term “about.” Unless indicated to the contrary, the numerical parameters set forth in the following specification and attached claims are approximations that can vary depending upon the desired properties sought to be obtained by the present invention.

[0023] Notwithstanding that the numerical ranges and parameters setting forth the broad scope of the invention are approximations, the numerical values set forth in the specific examples are reported as precisely as possible. Any measured numerical value, however, may inherently contain certain errors resulting from the standard deviation found in their respective testing measurements.

[0024] Also, it should be understood that any numerical range recited herein is intended to include all sub-ranges subsumed therein. For example, a range of “1 to 10” is intended to include any and all sub-ranges between and including the recited minimum value of 1 and the recited maximum value of 10, that is, all subranges beginning with a minimum value equal to or greater than 1 and ending with a maximum value equal to or less than 10, and all subranges in between, e.g., 1 to 6.3, or 5.5 to 10, or 2.7 to 6.1.

[0025] As used herein, the terms “comprising”, “comprise”, or “comprised”, and variations thereof, are meant to be open ended.

[0001] With reference to the figures, the present disclosure is directed to methods for accurately and precisely aligning articles in plastic manufacturing (e.g., thermoplastic, laser, and/or ultrasonic welding) processes. In particular, the methods disclosed herein can be used for connecting a first molded part having discontinuous surfaces, such as surfaces of different heights, to a second molded part having corresponding surfaces of different heights at multiple areas of contact or welding joints. Beneficially, the methods disclosed herein allow for connecting the molded parts together with multiple welded joints and without needing to create gaps or spaces between some portions of the molded parts. Also, the methods disclosed herein allow for molded parts to be made with less precision (e.g., having a less tight tolerance) than if surfaces of molded parts were connected directly together by conventional welding methods. [0002] The methods disclosed herein could be used in the manufacture of any plastic article, but may find particular use in fluidics. For example, the methods disclosed herein can be used to create sealed channels and reservoirs in molded fluidic articles, such as manifolds, cartridges, cuvettes, or cassettes. The articles and devices including the sealed channels and reservoirs can be used for analytical techniques, fluid distribution, containment, and/or storage. In particular, the methods of the present disclosure can be used to prevent egress or ingress of liquid into or from the article or into or from an area of the article to another area of the article. [0003] More specifically, in some examples, the methods of the present disclosure can be adapted so that gaps, spaces, cavities, and other spacing features are not needed between molded parts of an assembly or device. For example, as previously described, typical welding methods for aligning thermoplastic elements to be welded into a single, e.g. monolithic, structure may be accurate. However, conventional welding methods, as known in the prior art, may not result in sufficient precision needed for articles requiring accurate and repeatable alignment of two or more elements welded to form the monolithic structure. Also, as previously described, conventional methods for forming articles with welded parts can include designing or providing gaps, spaces, and dead volumes between molded parts, which can cause fluid leaks and sample loss. Accordingly, the positioning and alignment methods of the present disclosure are configured to provide sealed articles without gaps or dead volumes, but which do not use elastomeric seals at connection points or joints between parts of the article.

[0004] The present disclosure is also directed to fluid containing articles and devices, such as a manifold, cuvette, cartridge, or cassette, including fluid channels and reservoirs that are sealed by a secure and substantially leak-free seal without using internal seals or gaskets, such as seals or gaskets formed from natural or synthetic rubber or silicone. Instead, the sealed joints in the articles and devices of the present disclosure are formed by the precision alignment methods disclosed herein for forming precisely aligned joints between plastic parts, such as parts having surfaces of different heights, by processes, such as ultrasonic welding, and without gaps, spaces, or dead volumes, where fluids may collect.

Conventional Alignment Methods

[0026] For sake of comparison, FIG. 1 schematically depicts a conventional thermoplastic welding method, as known in the prior art, where two elements, such as plates 10, 12, having surfaces of different heights are welded together leaving a gap or space between portions of the plates 10, 12. In this method, a protruding surface or ridge 14 has a height (shown by distance Al in FIG. 1) that is larger than the depth (shown by distance A2 in FIG. 1) of a recessed surface or notch 16 into which the protruding surface or ridge 14 is placed. To join the plates 10, 12, the plates 10, 12 are pressed together, which forms a gap 18 between the plates 10, 12. The protruding surface or ridge 14 is thermally-welded to the recessed surface or notch 16, using any technique suitable for welding thermoplastics, such as laser-welding or ultrasonic welding. For illustrative purposes, a fluid reservoir or liquid containment area 20, formed between the plates 10, 12, is shown. In use, as described above, liquids in the fluid reservoir or liquid containment area 20, between the plates 10, 12 can move into the gap 18 and into the recessed surface or notch 16.

Positioning and Alignment Methods using Spacing Ribs

[0027] As described herein, the methods of the present disclosure provide manufactured plastic devices and articles formed from parts, such as parts having surfaces of different heights, that are connected together by a plastic processing method, such as thermoplastic, laser, and/or ultrasonic welding, without forming gaps, such as the gap 18 in FIG. 1, or openings found in objects made by traditional plastic processes.

[0028] FIG. 2A schematically depicts a thermoplastic welding method of the present disclosure in which the two elements, such as a fist plate 10 and a second plate 12, are welded together without a gap. As used herein, a plate 10, 12 refers to a substantially flat part including an inwardly facing surface, an outwardly facing surface, and a peripheral edge extending between the inwardly facing surface and the outwardly facing surface. The plates 10, 12 can be formed from a rigid thermoplastic material which can be melted by a welding process (e.g., ultrasonic or laser welding). For example, the thermoplastic material can be polyester, polycarbonate, polypropylene, polyethylene, polyethylene terephthalate, acrylonitrile butadiene styrene, or combinations thereof.

[0029] As previously described, the plates 10, 12 can include complex arrangements of reservoirs and channels designed for moving the fluid through the article or device. For example, the first plate 10 and the second plate 12 can be fluidic structures including grooves, recesses, protrusions, ridges, or other structures positioned such that when the plates 10, 12 are joined together, one or more reservoirs are formed for retaining, for example, biological fluids within reservoirs of the article or device.

[0030] As shown in FIG. 2A, by way of example, the first plate 10 can comprise a recessed surface or notch 16a and a protruding surface or ridge 14a. The second plate 12 comprises corresponding structures, such as a recessed surface or notch 16b positioned proximate to the ridge 14a of the first plate 10, a protruding surface or ridge 14b proximate to the notch 16a of the first plate 10, and at least one rib 22 extending from the protruding surface or ridge 14b of the second plate 12. In other examples, the rib 22 can extend from the recessed surface 16a of the first plate 10. The rib 22 can be positioned such that a surface of the rib 22 comes into contact with the protruding surface or ridge 14b of the second plate 12 as the plates 10, 12 are joined together.

[0031] In some examples, the welding method comprises moving the first plate 10 towards the second plate 12, thereby causing the recessed surface or notch 16a of the first plate 10 to contact a surface of the rib 22 of the second plate 12. Alternatively, for a rib 22 extending from the recessed surface or notch 16a of the first plate 10, a surface of the rib 22 can come into contact with the protruding surface or ridge 14b of the second plate 12. The method further comprises, with the rib 22 in contact with the recessed surface or notch 16a of the first plate 10 or with the protruding surface or ridge 14b of the second plate 12, melting the rib 22 (e.g., by a laser welding, ultrasonic welding, or other suitable welding processes), thereby causing the protruding surface or ridge 14a of the first plate 10 to come into contact with the recessed surface or notch 16b of the second plate 12. The method can further comprise welding (e.g., by a laser welding, ultrasonic welding, or other suitable welding processes) the first plate 10 to the second plate 12 at areas of contact 24 between the protruding surface or ridge 14a of the first plate 10 and the recessed surface or notch 16b of the second plate 12. The melting and welding steps can be performed sequentially (e.g., with melting or welding of the rib 22 occurring before welding the areas of contact 24 between the recessed surface or notch 16b and the protruding surface or ridge 14a) or simultaneously (e.g., with melting or welding of the rib 22 occurring at the same time as welding the areas of contact 24 between the recessed surface or notch 16b and the protruding surfaces or ridge 14a).

[0032] The welding methods of the present disclosure can be performed using a variety of welding processes for plastics, as are known in the art, including laser welding, ultrasonic welding, contact welding, non-contact infrared welding, induction welding, and/or any other welding techniques commonly used for joining plastic structures. It is believed that laser welding may be a preferred welding method for the plastic processes disclosed herein because a laser beam used for laser welding can be precisely aimed at specific structures of the first or second plate 10, 12. For example, a laser beam of a laser welding tool can be aimed to melt the rib 22 without softening, deforming, or melting any other portions of the first plate 10. Further, the laser beam can be sufficiently powerful to quickly and efficiently melt the rib 22 to bring the first plate 10 into contact with the second plate 12 in appropriate alignment.

[0033] By contrast, less accurate welding processes, welding processes that are difficult to control, and/or welding processes used to heat large areas of a plate or substrate may be less suitable for the welding method of the present disclosure because such less accurate methods may inadvertently soften or melt portions of the first plate 10 or the second plate 12 that are not intended to be deformed. For example, ultrasonic welding may not be able to precisely and fully melt the rib 22 of the first plate 10 to correctly align the first plate 10 and the second plate 12 in the manner described hereinabove. Ultrasonic welding can be suitable for joining areas of surfaces together, such as for forming a weld at the area of contact 24 between the first plate 10 and the second plate 12, as shown in FIG. 2A.

[0034] In some examples, the sizes or elevations of the various surfaces of the plates 10, 12 are selected to allow for precise alignment of the first plate 10 relative to the second plate 12. For example, as shown in FIG. 2A, an elevation of the protruding surface or ridge 14a of the first plate 10 (defined as a vertical distance Al between the recessed surface or notch 16a and the protruding surface or ridge 14a) is greater than a sum of the elevation of the protruding surface or ridge 14b (defined as a vertical distance A2 between the recessed surface or notch 16b and the protruding surface or ridge 14b) of the second plate 12 and an elevation of the rib 22 (defined as a vertical distance A3 between the protruding surface or ridge 14b of the second plate 12 and a surface of the rib 22). [0035] As previously described, the thermoplastic welding method of the present disclosure can be used for forming sealed fluidic structures, such as a fluid channel, fluid chamber, and/or a fluid reservoir. For example, an area of contact between the melted rib 22 and the recessed surface or notchl6a of the first plate 10 can form a sealed surface that can be positioned in proximity to, immediately adjacent to, and/or can define a portion of the fluid channel, reservoir, or chamber of a fluidic device or article.

[0036] For example, as shown in FIG. 2B, there can be a fluid channel, fluid chamber, and/or a fluid reservoir F immediately adjacent to the melted rib 22 such that the rib 22 defines a portion of the fluid channel, reservoir, or chamber F. The melted rib 22 can be configured to seal and/or retain fluid within the fluid channel, fluid chamber, and/or a fluid reservoir F. The weld joint formed at the area of contact 24 between the first plate 10 and the second plate 12 can also form a seal. The seal at the area of contact 24 can prevent any fluid that moves past or over the melted rib 22 from leaking through the joint and/or from a device or fluidic structure that includes the welded joint.

Fluidic Cassette including Sealed Reservoirs

[0037] The methods for joining the first plate 10 to the second plate 12 to form a sealed reservoir or channel without using an elastomeric seal or gasket of the present disclosure can be used for forming plastic microfluidic articles and devices. For example, the methods disclosed herein can be used for manufacture of a cartridge, cuvette, or cassette including internal reservoirs, filters, flow channels, and similar structures for containing biological samples. Examples of fluid devices including parts that can be connected together using the aligning and positioning methods of the present disclosure are described, for example, in U.S. Patent No. 10,188,967, entitled “Filter arrangement with slider valve and method for using the same”, U.S. Patent No. 11,073,450, entitled “Filter arrangement using elution fluid and method for using the same,” and U.S. Patent No. 11,002,752, entitled “System for conducting the identification of bacteria in biological samples,” the disclosure of each of which is incorporated by reference herein in its entirety.

[0038] In some examples, the methods disclosed herein can be used for forming a cassette 110 for containing a fluid biological sample. As used herein, a “cassette” refers to a fluidic article or device comprising one or more enclosed reservoirs configured to contain a sufficient volume of a biological sample for use in biological testing. The cassette 110 can also include fluid channels extending between the reservoir and inflow and/or outflow ports, cavities, inlets, or outlets of the cassette 110 configured for introducing the fluid sample into the cassette 110 and/or for permitting the expulsion of portions of the sample from the cassette 110.

[0039] FIGS. 3A-4C show an example of a cassette 110 including sealed joints or connections between parts formed by the alignment and positioning methods of the present disclosure. Specifically, FIG. 3 A shows a perspective view of the fluidic cassette 110 including the reservoirs and fluid channels enclosed between outwardly facing plates and an intermediate tray or body of the cassette. FIG. 3B is a front view of the cassette 110. FIG. 3C is a rear view of the cassette 110. FIGS. 4A-4C show cross-sectional views of the cassette 110 showing interfaces or joints between parts of the cassette 110 that form or seal the fluid channel or reservoir.

[0040] As shown in FIGS. 3A-4B, the cassette 110 comprises a body 112. The body 112 can be a substantially flat structure, such as a tray, comprising a substantially flat first or upper side 114, an opposing substantially flat second or lower side 116, and a peripheral edge 118 extending between the upper side 114 and the lower side 116. The body 112 further includes recesses 120 or openings for forming fluid containing reservoirs 122 of the cassette 110. For example, the body 112 can include recesses 120 extending inwardly from the upper side 114 or the lower side 116 of the body 112. In some examples, the recesses 120 can be through- holes extending between the upper side 114 and the lower side 116 of the body 112 and, as described in further detail herein, enclosed by a top plate attached to the upper side 114 and a bottom plate attached to the lower side 116, thereby forming the reservoir 122. Alternatively or in addition, the body 112 can include shallow recesses 120 or depressions extending inwardly from the upper side 114 or the lower side 116 and covered by a plate to form the reservoir 122. In some examples, the body 112 can also include narrow grooves or channels 124 carved, machined, or molded into the surfaces of the body 112 for conducting fluid to or from the reservoirs 122 and through the body 112.

[0041] As shown in FIGS. 3A-4B, the cassette 110 also includes a first element, such as an upper cover plate 126, joined to a body 112 of the cassette 110, for at least partially enclosing the fluid reservoirs 122 of the cassette 110. The upper cover plate 126 can comprise an outwardly facing side 128 and an inwardly facing side 130 in contact with and/or connected to the body 112. The inwardly facing side 130 can include a protruding surface 132 and a recessed surface 134 for joining the upper cover plate 126 to the body 112 by the aligning and positioning method of the present disclosure.

[0042] In some examples, as shown in FIGS. 3A-4B, the cassette 110 includes multiple upper cover plates 126, each of which covers a different reservoir 122 of the cassette 110. In other examples, the cassette 110 can include one larger upper cover plate 126 that covers or encloses multiple reservoirs 122 of the cassette 110.

[0043] In some examples, the cassette 110 can also include a lower cover plate 136 mounted to the lower side 116 of the body 112. The lower cover plate 136 can comprise an outwardly facing side 138 and an inwardly facing side 140, which includes a protruding surface 142 and a recessed surface 144. The lower plate 136 can be positioned, for example, over a through hole of the body 112, in order to enclose a reservoir 122 between the upper plate 126, the body 112, and the lower plate 136.

[0044] The plates 126, 136 and body 112 of the cassette are generally formed from plastic materials that can be processed by the welding techniques (e.g., laser welding, ultrasonic welding, contact welding, non-contact / infrared welding, or induction welding, preferably by laser welding) described hereinabove. For example, the body 112 and plates 126, 136 can be formed from one or more substantially rigid thermoplastic elastomeric materials, such as polyester, polycarbonate, polypropylene, polyethylene, polyethylene terephthalate, acrylonitrile butadiene styrene, or combinations thereof.

[0045] With specific reference to FIG. 4C, the cassette 110 also includes at least one partially melted rib 146 extending from the inwardly facing side 130, 140 of either the upper cover plate 126 or the lower cover plate 136 towards the body 112. For example, the rib 146 can extend between a recessed surface 134, 144 of either the upper cover plate 126 or the lower cover plate 136 and a protruding surface 132, 142 of the other of the upper cover plate 126 or the lower cover plate 136. In other examples, the partially melted rib 146 can extend from one of the sides of the body 112, such as from a protruding surface of the body 112, towards the inwardly facing surface 130, 140 of either the upper cover plate 126 or the lower cover plate 136.

[0046] As used herein, a “partially melted rib” refers to a rib which has been deformed by a welding process, such as ultrasonic welding or laser welding, meaning that the partially melted rib has a different shape form its shape as originally formed. Also, the partially melted rib can be adhered to another surface, thereby securing, for example, the upper cover plate 126 to the body 112.

[0047] More specifically, as shown in FIG. 4C, the partially melted rib 146 can join the upper side 114 of the body 112 to the inwardly facing side 130 of the upper cover plate 126 at a position adjacent to the reservoir 122, which forms a fluid-tight seal for the reservoir 122. Also, a portion of the protruding surface 132 of the upper cover plate 126 can be joined to a portion of a recessed surface of the upper side 114 of the body 112 forming a welded joint 148. Specifically, the welded joint 148 can be formed at the contact point between the protruding surface 132 and the upper side 114 of the body 112, thereby enhancing the fluid-tight seal enclosing the reservoir 122.

[0048] In some examples, the cassette 110 can also include a fluid-tight connection or seal between the inwardly facing side 140 of the lower cover plate 136 and the lower side 116 of the body. The fluid-tight connection or seal can be formed using the previously described positioning and alignment method, in which a rib 146 extending from the inwardly facing surface 140 of the lower cover plate 136 is melted in order to bring a portion of the lower side 116 of the body 112 into contact with the inwardly facing surface 140 of the lower plate 136. A welded joint can be formed between the lower cover plate 136 and the body 112 for creating the fluid-tight seal between the lower cover plate 136 and the body 112. Accordingly, as shown in the figures, the lower cover plate 136 can be mounted to the lower side 116 of the body 112 forming a fluid reservoir 122 defined by inwardly facing surfaces 130, 140 of the upper cover plate 126 and the lower cover plate 136 and the recess 120 extending through the body 112.

[0049] FIG. 5 shows another example of a cassette 110 including an upper plate 126 and a lower plate 136 connected to a body 112. The connection between the plates 126, 136 and the body 112 forms or encloses a fluid reservoir 122, similar to fluid reservoirs of previous examples. However, the example in FIG. 5 differs from the interface between the plates 126, 136 and the body 112 shown in FIG. 4C because the interface in FIG. 5 does not include a melted rib for providing positioning and alignment of the plates 126, 136. Instead, the interface or connection between plates 126, 126 in FIG. 5 is made by a traditional welding method known in the prior art, as shown in FIG. 1 and as previously described. Accordingly, the upper plate 126 and the lower plate 136 are connected to a narrow section or tab of the body 112. However, as described previously in connection with FIG. 1, intentional gaps are provided between the plates 126, 136 and the body 112 because it is difficult to precisely align the plates 126, 136 in an appropriate manner. As previously described, the intentional gaps may cause leaking or fluid loss from the reservoir 122 for the cassette of FIG. 5 resulting in less accurate sample collection and analysis.

[0050] By contrast, as described herein, cartridges or cassettes 110, such as the cassettes 110 shown in FIGS. 3A-4C, made by connecting parts, such as the plates 126, 136 and body 112 together, using the positioning and alignment methods disclosed herein do not include intentional gaps. Instead, in the cassette 110 of FIGS. 3A-4C, the plates 126, 136 are appropriately aligned with the body 112 as the ribs are melted or deformed and without using gaskets or seals. Also, the connections between the plate 126, 136 and body 112 in FIGS. 3A-4C are made without intentional gaps or spaces. Accordingly, fluid-tight seals around the reservoirs 122 in FIGS. 3A-4C are created and maintained.

[0051] While examples of the welding methods and fluidic articles and devices of the present disclosure are shown in the accompanying figures and described hereinabove in detail, other examples will be apparent to, and readily made by, those skilled in the art without departing from the scope and spirit of the invention. Accordingly, the foregoing description is intended to be illustrative rather than restrictive. The invention described hereinabove is defined by the appended claims and all changes to the invention that fall within the meaning and the range of equivalency of the claims are to be embraced within their scope.

[0052] Non-limiting aspects or embodiments of the present invention will now be described in the following numbered clauses:

[0053] Clause 1: A method of welding a side of a first element to a side of a second element, wherein (i) the side of the first element comprises a recessed surface and a protruding surface,

(ii) the side of the second element comprises a recessed surface and a protruding surface, and

(iii) at least one rib extending from the first element, optionally from the recessed surface of the first element, or from the second element, optionally from the protruding surface of the second element, the method comprising: moving the first element towards the second element, thereby causing a surface of the at least one rib to contact the first element or the second element; and with the at least one rib in contact with the first element or the second element, melting the rib, thereby causing the protruding surface of the first element to contact the recessed surface of the second element.

[0054] Clause 2: The method of clause 1, wherein the first element and/or the second element comprises a plate having an inwardly facing surface comprising the protruding surface and/or the recessed surface, an outwardly facing surface, and a peripheral edge extending between the inwardly facing surface and the outwardly facing surface, and wherein the plate comprises a rigid thermoplastic polymer, such as polyester, polycarbonate, polypropylene, polyethylene, polyethylene terephthalate, or acrylonitrile butadiene styrene.

[0055] Clause 3: The method of clause 1 or clause 2, wherein melting the at least one rib comprises melting the at least one rib by laser welding, ultrasonic welding, contact welding, non-contact infrared welding, or induction welding, preferably by laser welding.

[0056] Clause 4: The method of clause 3, further comprising welding the first element to the second element at areas of contact between the protruding surface of the first element and the recessed surface of the second element, such that the first element is connected to the second element by a first welded joint proximate to the melted at least one rib, and a second welded joint between the protruding surface of the first element and the recessed surface of the second element.

[0057] Clause 5: The method of clause 4, wherein welding the at least one rib and welding the area of contact between the protruding surface of the first element and the recessed surface of the second element occurs simultaneously.

[0058] Clause 6: The method of any of clauses 1-5, wherein an elevation of the protruding surface of the first element is greater than the elevation of the protruding surface of the second element.

[0059] Clause 7: The method of clause 6, wherein the elevation of the protruding surface is a vertical distance between the recessed surface and the protruding surface.

[0060] Clause 8: The method of any of clauses 1-7, wherein an elevation of the protruding surface of the first element is greater than a sum of the elevation of the protruding surface of the second element and an elevation of the rib of the second element.

[0061] Clause 9: The method of clause 8, wherein the elevation of the rib is a vertical distance between the protruding surface of the second element and a surface of the rib.

[0062] Clause 10: The method of any of clauses 1-9, wherein the protruding surface is on a periphery of the side of the first element and the recessed surface is over a central portion of the side of the first element, at least partially enclosed by the protruding surface.

[0063] Clause 11: The method of clause 10, wherein the recessed surface of the second element is on a periphery of the second element and the protruding surface is over a central portion of the side of the first element.

[0064] Clause 12: The method of any of clauses 1-11, wherein the at least one rib comprises an annular rib.

[0065] Clause 13: The method of any of clauses 1-12, wherein, following welding, there is a gap between the recessed surface of the first element and the protruding surface of the second element.

[0066] Clause 14: The method of clause 13, wherein a vertical distance of the gap is less than an elevation of the at least one rib.

[0067] Clause 15: The method of clause 14, wherein the elevation of the at least one rib is a vertical distance between the protruding surface of the second portion and the surface of the at least one rib. [0068] Clause 16: The method of any of clauses 1-15, wherein the first element and the second element form an upper portion and a lower portion, respectively, of a cuvette, cartridge, or cassette for containing a fluid sample.

[0069] Clause 17: The method of clause 16, wherein the welded area of contact between the protruding surface of the first element and the recessed surface of the second element forms a fluid tight seal sufficient for retention of fluid within a fluid reservoir formed between the side of the first element and the side of the second element.

[0070] Clause 18: The method of any of clauses 1-17, wherein the contact between the protruding surface of the first element and the recessed surface of the second element is a fluid- tight connection provided without an elastomeric seal or gasket.

[0071] Clause 19: The method of any of clauses 1-18, wherein the first element is connected to the second element by at least a first welded joint and a second welded joint, and wherein the first welded joint and the second welded joint are separate from one another and at different heights relative to the first element and/or the second element.

[0072] Clause 20: A cassette for containing a fluid biological sample, comprising: at least one upper cover element comprising an outwardly facing side and an inwardly facing side, the inwardly facing side comprising a protruding surface and a recessed surface; and a body comprising a first side mounted to the at least one upper cover element, the first side of the body comprising a recessed surface and a protruding surface, wherein the cassette further comprises at least one partially melted rib extending from the at least one upper cover element, optionally from the recessed surface of the at least one upper cover element, or from the first side of the body, optionally from the protruding surface of the first side of the body, wherein the partially melted rib joins the first side of the body to the at least one upper cover element, and wherein at least a portion of the protruding surface of the at least one upper cover element is joined to at least a portion of the recessed surface of the first side of the body by a welded joint.

[0073] Clause 21: The cassette of clause 20, wherein the at least one upper cover element and/or the body comprises a plate having an inwardly facing surface comprising the protruding surface and/or the recessed surface, an outwardly facing surface, and a peripheral edge extending between the inwardly facing surface and the outwardly facing surface, and wherein the plate comprises a rigid thermoplastic polymer, such as polyester, polycarbonate, polypropylene, polyethylene, polyethylene terephthalate, or acrylonitrile butadiene styrene. [0074] Clause 22: The cassette of clause 20 or clause 21, further comprising at least one lower cover element mounted to a second side of the body forming at least one fluid reservoir defined by surfaces of the at least one upper cover element, the at least one lower cover element, and the body.

[0075] Clause 23: The cassette of clause 22, wherein the at least one lower cover element comprises an inwardly facing side mounted to the body, the inwardly facing side comprising a protruding surface and a recessed surface, and wherein the second side of the body comprises a recessed surface and a protruding surface.

[0076] Clause 24: The cassette of clause 23, wherein the cassette further comprises at least one partially melted rib extending from the second side of the body, optionally from the protruding surface of the second side of the body, or from the at least one lower cover element, optionally from the recessed surface of the at least one lower cover element, wherein the partially melted rib joins the at least one lower cover element and the second side of the body at a first welded joint, and wherein at least a portion of the protruding surface of the at least one lower cover element is joined to at least a portion of the recessed surface of the second side of the body at a second welded joint.

[0077] Clause 25: The cassette of any of clauses 20-24, wherein the portion of the protruding surface of the at least one upper cover element that is joined to the portion of the recessed surface of the body by at least one of laser welding, ultrasonic welding, contact welding, noncontact infrared welding, or induction welding, preferably by laser welding.

[0078] Clause 26: The cassette of any of clauses 20-25, wherein the portions of the protruding surface of the at least one upper cover element and the recessed surface of the body are joined in a fluid-tight connection to prevent fluid loss from a reservoir of the cassette.

[0079] Clause 27: The cassette of any of clauses 20-26, wherein the portions of the protruding surface of the at least one upper cover element and the recessed surface of the body are joined in a fluid-tight connection provided without an elastomeric seal or gasket.

[0080] Clause 28: The cassette of any of clauses 20-27, wherein the at least one upper cover element is connected to the body by at least a first welded joint and a second welded joint, and wherein the first welded joint and the second welded joint are separate from one another and at different heights relative to the at least one upper cover element and/or the body.

Claims

THE INVENTION CLAIMED IS:

1. A method of welding a side of a first element to a side of a second element, wherein (i) the side of the first element comprises a recessed surface and a protruding surface, (ii) the side of the second element comprises a recessed surface and a protruding surface, and (iii) at least one rib extending from the first element, optionally from the recessed surface of the first element, or from the second element, optionally from the protruding surface of the second element, the method comprising: moving the first element towards the second element, thereby causing a surface of the at least one rib to contact the first element or the second element; and with the at least one rib in contact with the first element or the second element, melting the rib, thereby causing the protruding surface of the first element to contact the recessed surface of the second element.

2. The method of claim 1, wherein the first element and/or the second element comprises a plate having an inwardly facing surface comprising the protruding surface and/or the recessed surface, an outwardly facing surface, and a peripheral edge extending between the inwardly facing surface and the outwardly facing surface, and wherein the plate comprises a rigid thermoplastic polymer, such as polyester, polycarbonate, polypropylene, polyethylene, polyethylene terephthalate, or acrylonitrile butadiene styrene.

3. The method of claim 1, wherein melting the at least one rib comprises melting the at least one rib by laser welding, ultrasonic welding, contact welding, non-contact infrared welding, or induction welding, preferably by laser welding.

4. The method of claim 3, further comprising welding the first element to the second element at areas of contact between the protruding surface of the first element and the recessed surface of the second element, such that the first element is connected to the second element by a first welded joint proximate to the melted at least one rib, and a second welded joint between the protruding surface of the first element and the recessed surface of the second element.

5. The method of claim 4, wherein welding the at least one rib and welding the area of contact between the protruding surface of the first element and the recessed surface of the second element occurs simultaneously.

6. The method of claim 1, wherein an elevation of the protruding surface of the first element is greater than the elevation of the protruding surface of the second element.

7. The method of claim 6, wherein the elevation of the protruding surface is a vertical distance between the recessed surface and the protruding surface.

8. The method of claim 1, wherein an elevation of the protruding surface of the first element is greater than a sum of the elevation of the protruding surface of the second element and an elevation of the rib of the second element.

9. The method of claim 8, wherein the elevation of the rib is a vertical distance between the protruding surface of the second element and a surface of the rib.

10. The method of claim 1, wherein the protruding surface is on a periphery of the side of the first element and the recessed surface is over a central portion of the side of the first element, at least partially enclosed by the protruding surface.

11. The method of claim 10, wherein the recessed surface of the second element is on a periphery of the second element and the protruding surface is over a central portion of the side of the first element.

12. The method of claim 1, wherein the at least one rib comprises an annular rib.

13. The method of claim 1, wherein, following welding, there is a gap between the recessed surface of the first element and the protruding surface of the second element.

14. The method of claim 13, wherein a vertical distance of the gap is less than an elevation of the at least one rib.

15. The method of claim 14, wherein the elevation of the at least one rib is a vertical distance between the protruding surface of the second portion and the surface of the at least one rib.

16. The method of claim 1, wherein the first element and the second element form an upper portion and a lower portion, respectively, of a cuvette, cartridge, or cassette for containing a fluid sample.

17. The method of claim 16, wherein the welded area of contact between the protruding surface of the first element and the recessed surface of the second element forms a fluid tight seal sufficient for retention of fluid within a fluid reservoir formed between the side of the first element and the side of the second element.

18. The method of claim 1, wherein the contact between the protruding surface of the first element and the recessed surface of the second element is a fluid-tight connection provided without an elastomeric seal or gasket.

19. The method of claim 1, wherein the first element is connected to the second element by at least a first welded joint and a second welded joint, and wherein the first welded joint and the second welded joint are separate from one another and at different heights relative to the first element and/or the second element.

20. A cassette for containing a fluid biological sample, comprising: at least one upper cover element comprising an outwardly facing side and an inwardly facing side, the inwardly facing side comprising a protruding surface and a recessed surface; and a body comprising a first side mounted to the at least one upper cover element, the first side of the body comprising a recessed surface and a protruding surface, wherein the cassette further comprises at least one partially melted rib extending from the at least one upper cover element, optionally from the recessed surface of the at least one upper cover element, or from the first side of the body, optionally from the protruding surface of the first side of the body,

19 wherein the partially melted rib joins the first side of the body to the at least one upper cover element, and wherein at least a portion of the protruding surface of the at least one upper cover element is joined to at least a portion of the recessed surface of the first side of the body by a welded joint.

21. The cassette of claim 20, wherein the at least one upper cover element and/or the body comprises a plate having an inwardly facing surface comprising the protruding surface and/or the recessed surface, an outwardly facing surface, and a peripheral edge extending between the inwardly facing surface and the outwardly facing surface, and wherein the plate comprises a rigid thermoplastic polymer, such as polyester, polycarbonate, polypropylene, polyethylene, polyethylene terephthalate, or acrylonitrile butadiene styrene.

22. The cassette of claim 20, further comprising at least one lower cover element mounted to a second side of the body forming at least one fluid reservoir defined by surfaces of the at least one upper cover element, the at least one lower cover element, and the body.

23. The cassette of claim 22, wherein the at least one lower cover element comprises an inwardly facing side mounted to the body, the inwardly facing side comprising a protruding surface and a recessed surface, and wherein the second side of the body comprises a recessed surface and a protruding surface.

24. The cassette of claim 23, wherein the cassette further comprises at least one partially melted rib extending from the second side of the body, optionally from the protruding surface of the second side of the body, or from the at least one lower cover element, optionally from the recessed surface of the at least one lower cover element, wherein the partially melted rib joins the at least one lower cover element and the second side of the body at a first welded joint, and wherein at least a portion of the protruding surface of the at least one lower cover element is joined to at least a portion of the recessed surface of the second side of the body at a second welded joint.

20

25. The cassette of claim 20, wherein the portion of the protruding surface of the at least one upper cover element that is joined to the portion of the recessed surface of the body by at least one of laser welding, ultrasonic welding, contact welding, non-contact infrared welding, or induction welding, preferably by laser welding.

26. The cassette of claim 20, wherein the portions of the protruding surface of the at least one upper cover element and the recessed surface of the body are joined in a fluid-tight connection to prevent fluid loss from a reservoir of the cassette.

27. The cassette of claim 20, wherein the portions of the protruding surface of the at least one upper cover element and the recessed surface of the body are joined in a fluid-tight connection provided without an elastomeric seal or gasket.

28. The cassette of claim 20, wherein the at least one upper cover element is connected to the body by at least a first welded joint and a second welded joint, and wherein the first welded joint and the second welded joint are separate from one another and at different heights relative to the at least one upper cover element and/or the body.

21