KR-102960748-B1 - Plastic Microfluidic Chip Capable of Decomposition and Assembly

Abstract

According to one aspect of the present invention, a detachable plastic microfluidic chip may be provided, comprising a lower body having a microfluidic channel that moves a sample liquid by capillary force, and an upper body that is coupled to the lower body to form a capillary barrier that acts as a watertight barrier along the fluid path of the microfluidic channel, and providing a friction assembly having a mechanical coupling structure that is detachable between the lower body and the upper body. According to the detachable plastic microfluidic chip of the present invention, since a method of manufacturing the plastic microfluidic chip using 3D printing technology is utilized, the design of the microfluidic chip can be easily changed and the initial manufacturing cost is low.

Inventors

• 김호진
• 안혜진
• 김다빈
• 김주영

Assignees

• 동서대학교 산학협력단

Dates

Publication Date

20260512

Application Date

20230302

Claims (5)

1. A lower body having a microfluidic channel through which a sample liquid moves by capillary force; An upper body coupled to the lower body and arranged to form a capillary barrier that acts as a watertight barrier along the fluid flow path of the microfluidic channel; and It includes a friction assembly formed with a mechanical coupling structure on the lower body and the upper body to detachably connect the lower body and the upper body; The above friction assembly is, A first boss portion formed to be distributed on the upper edge portion of the lower body; and A second boss part formed to be frictionally joined to the first boss part by being press-fitted thereto, and distributed on the bottom edge of the upper body; A detachable plastic microfluidic chip including
2. In paragraph 1, The first boss portion comprises a plurality of cylindrical first friction bosses clustered at a certain distance apart, and the second boss portion comprises a plurality of cylindrical second friction bosses clustered at a certain distance apart to interlock with the first friction bosses. A detachable plastic microfluidic chip characterized in that the first boss part and the second boss part maintain a bonding force through the frictional force between the first friction bosses and the second friction bosses, and the alignment of the lower body and the upper body is automatically aligned during the assembly process of the first friction bosses and the second friction bosses.
3. In paragraph 2, A boss receiving groove is formed on the upper edge of the lower body in a recessed, engraved shape over a certain section, and The first friction bosses of the first boss portion are formed inside the boss receiving groove, and A detachable plastic microfluidic chip characterized by having second friction bosses of the second boss part protruding from the lower edge of the upper body at a height that is inserted into the boss receiving groove.
4. In paragraph 3, The above lower body is formed of a plate-shaped plastic base having a certain thickness, and A microfluidic channel is formed in the center of the upper surface of the lower body to transport the sample liquid by capillary force in the longitudinal direction of the lower body, and The microfluidic channel comprises: a supply section connected to the sample liquid inlet to supply the sample liquid; a movement section formed to allow the sample liquid to move by capillary force along a narrow passage that is narrowed in width along the longitudinal direction of the rear end of the supply section; and a capillary pump formed to increase the liquid suction amount in an expansion region that is widened in width along the longitudinal direction of the rear end of the movement section. A detachable plastic microfluidic chip characterized by the formation of adhesion protrusions within the above-mentioned capillary pump to increase capillary force.
5. In paragraph 4, The above upper body is formed of a plate-shaped plastic base having a certain thickness, and A facing portion with a shape corresponding to the microfluidic channel is formed in the center of the bottom surface of the upper body along the longitudinal direction of the upper body, and A guide groove having a certain width and depth is formed on the outer perimeter of the above-mentioned face portion, and a capillary barrier is formed between the guide groove and the microfluidic channel to prevent the sample liquid from escaping the interface using a gas-liquid interface. A detachable plastic microfluidic chip characterized by having an exhaust guide for opening a portion of the end of the capillary pump of the microfluidic channel provided in a structure in which a portion of the rim of the upper body is cut.

Description

Plastic Microfluidic Chip Capable of Decomposition and Assembly The present invention relates to a microfluidic chip, and more specifically, to a detachable plastic microfluidic chip that is manufactured by dividing it into a lower body and an upper body using 3D printing and provides a friction assembly having a mechanical coupling structure that is detachable between the lower body and the upper body. Conventional methods for detecting pathogens involve cell culture, PCR, and enzyme immunoassay, and are criticized for being labor-intensive and requiring hours to days to obtain results (Foudeh et al., Microfluidic designs and techniques using lab-on-a-chip devices for pathogen detection for point-of-care diagnostics. Lab Chip, 2012, 12, 3249-3266). Accordingly, research on lab-on-a-chip (LOC) technology is underway to manufacture point-of-care (POC) devices, a next-generation bio-industry, which enable rapid, accurate detection using small sample volumes. This lab-on-a-chip technology plays a crucial role in analyzing biological and chemical samples within a single, miniaturized device. POC testing is widely applied in various hospitals and research institutions, and ideally, the use of minimal equipment is required. To conduct POC tests, products are being commercialized based on various types of devices. In particular, microfluidic devices are a field that has recently been gaining attention because, for example, they can achieve complex biochemical reactions using sample liquids with very small volumes. Currently, as technologies applied to biosensing and POC systems, (i) plastic (polymer)-based microfluidic devices and (ii) membrane-based devices are commonly used. The aforementioned devices are known to perform analysis on a small scale and within a short time compared to conventional technologies, consume less samples and reagents, and possess high analytical reproducibility (Ikeda et al., Rapid and simple detection of food poisoning bacteria by bead assay with a microfluidic chip-based system, Journal of Microbiological Methods 67 (2006), 241-247). In this case, substances that can be analyzed or detected include glucose, cholesterol, proteins, enzymes, bacteria, viruses, nucleic acid sequences, etc. Among these, for plastic-based microfluidic devices used for POCs or lab-on-a-chip applications, polymethylsiloxane (PDMS) is typically used. Additionally, disposable devices are manufactured using polyethylene derivatives such as polycarbonate (PC), polystyrene (PS), and polypropylene (PP), or by using polymethyl methacrylate (PMMA) or cyclic olefin copolymer (COC) (e.g., U.S. Patent No. 6,790,599). In this regard, most plastic-based microfluidic devices utilize injection molding, a method typically employed in which a polymer is injected into a mold at high temperatures using a die and/or casting, cooled, and then separated from the mold. During this process, an inverse phase of the mold is formed on the plastic surface, and the resulting device and base plate are combined and sealed to manufacture the product. However, when fabricating the aforementioned microfluidic device, the upper and lower substrates are generally joined using thermal bonding, ultrasonic bonding, or optical methods. During this process, the materials used for bonding based on the molecular structure of the plastic surface may be limited, there are technical difficulties in bonding microstructures to precise locations, and there are disadvantages such as the formation of air bubbles or incomplete bonding during the device sealing process. Meanwhile, membrane-based devices utilize the capillary action of microporous membranes; for example, analytes contained in a mobile phase sample solution are separated from other compounds based on their binding affinity with capture molecules immobilized on a fixed solid phase. Membrane-based devices are utilized in various research and industrial fields because they allow for the easy immobilization of biomaterials and convenient detection of biomaterials at a low cost. Nitrocellulose is widely known as a commonly used membrane-type material. Nitrocellulose is fundamentally required to have a hydrophilic porous structure, as conventional POCT or rapid test kits utilize the hygroscopic properties of the sample. In addition, nitrocellulose has advantages such as a relatively low unit cost, capillary flow characteristics, high protein binding capacity, and relatively easy handling methods (direct casting or supported membranes). Furthermore, attempts have been made to use other types of materials, including nylon and PVDF membranes, but there are limitations to their widespread use due to costs and limited applications. However, in the case of membrane-based devices, the wettability of the liquid varies, and the speed at which the fluid moves after absorbing moisture is not constant. For this reason, surfactants are often used to control surface wettability, but surfactants can affect the patter