CN114798022A - Portable device and method for vacuumizing PDMS bubbles - Google Patents
Portable device and method for vacuumizing PDMS bubbles Download PDFInfo
- Publication number
- CN114798022A CN114798022A CN202210427544.0A CN202210427544A CN114798022A CN 114798022 A CN114798022 A CN 114798022A CN 202210427544 A CN202210427544 A CN 202210427544A CN 114798022 A CN114798022 A CN 114798022A
- Authority
- CN
- China
- Prior art keywords
- pdms
- piston
- cup body
- cover
- hole
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 239000004205 dimethyl polysiloxane Substances 0.000 title claims abstract description 105
- 229920000435 poly(dimethylsiloxane) Polymers 0.000 title claims abstract description 105
- 238000000034 method Methods 0.000 title claims abstract description 27
- 235000013870 dimethyl polysiloxane Nutrition 0.000 title claims abstract 17
- CXQXSVUQTKDNFP-UHFFFAOYSA-N octamethyltrisiloxane Chemical compound C[Si](C)(C)O[Si](C)(C)O[Si](C)(C)C CXQXSVUQTKDNFP-UHFFFAOYSA-N 0.000 title claims abstract 17
- 238000004987 plasma desorption mass spectroscopy Methods 0.000 title claims abstract 17
- 238000003756 stirring Methods 0.000 claims abstract description 7
- 239000003292 glue Substances 0.000 claims description 18
- 230000008093 supporting effect Effects 0.000 claims description 6
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 claims description 5
- 239000003431 cross linking reagent Substances 0.000 claims description 5
- 239000002243 precursor Substances 0.000 claims description 5
- 229910052710 silicon Inorganic materials 0.000 claims description 5
- 239000010703 silicon Substances 0.000 claims description 5
- 238000009434 installation Methods 0.000 claims description 4
- 238000001259 photo etching Methods 0.000 claims description 4
- 239000004033 plastic Substances 0.000 claims description 4
- 230000000149 penetrating effect Effects 0.000 claims description 2
- 238000009423 ventilation Methods 0.000 claims description 2
- 238000010438 heat treatment Methods 0.000 abstract description 11
- 239000007788 liquid Substances 0.000 abstract description 9
- 238000002360 preparation method Methods 0.000 abstract description 8
- 238000005086 pumping Methods 0.000 abstract description 7
- 238000005406 washing Methods 0.000 abstract description 4
- 238000007664 blowing Methods 0.000 abstract description 2
- 238000007711 solidification Methods 0.000 abstract description 2
- 230000008023 solidification Effects 0.000 abstract description 2
- 239000012528 membrane Substances 0.000 abstract 1
- 239000002184 metal Substances 0.000 abstract 1
- 239000000243 solution Substances 0.000 description 36
- 239000011259 mixed solution Substances 0.000 description 12
- 230000000694 effects Effects 0.000 description 10
- 238000004519 manufacturing process Methods 0.000 description 7
- 238000007789 sealing Methods 0.000 description 6
- 238000010586 diagram Methods 0.000 description 5
- 238000002474 experimental method Methods 0.000 description 5
- 238000000605 extraction Methods 0.000 description 5
- 238000002174 soft lithography Methods 0.000 description 5
- 239000000463 material Substances 0.000 description 4
- 239000002245 particle Substances 0.000 description 4
- 238000001291 vacuum drying Methods 0.000 description 4
- 230000005540 biological transmission Effects 0.000 description 3
- 230000000740 bleeding effect Effects 0.000 description 3
- 238000001723 curing Methods 0.000 description 3
- 238000007872 degassing Methods 0.000 description 3
- 238000004090 dissolution Methods 0.000 description 3
- 238000005516 engineering process Methods 0.000 description 3
- 230000033001 locomotion Effects 0.000 description 3
- 238000007514 turning Methods 0.000 description 3
- 238000010146 3D printing Methods 0.000 description 2
- -1 Polydimethylsiloxane Polymers 0.000 description 2
- 238000010923 batch production Methods 0.000 description 2
- 230000008901 benefit Effects 0.000 description 2
- 238000005266 casting Methods 0.000 description 2
- 238000011049 filling Methods 0.000 description 2
- 239000011521 glass Substances 0.000 description 2
- 239000012535 impurity Substances 0.000 description 2
- 238000003754 machining Methods 0.000 description 2
- 238000000520 microinjection Methods 0.000 description 2
- 238000003801 milling Methods 0.000 description 2
- 229920001343 polytetrafluoroethylene Polymers 0.000 description 2
- 239000004810 polytetrafluoroethylene Substances 0.000 description 2
- 238000000926 separation method Methods 0.000 description 2
- 239000010963 304 stainless steel Substances 0.000 description 1
- 239000004793 Polystyrene Substances 0.000 description 1
- 229910000589 SAE 304 stainless steel Inorganic materials 0.000 description 1
- NIXOWILDQLNWCW-UHFFFAOYSA-N acrylic acid group Chemical group C(C=C)(=O)O NIXOWILDQLNWCW-UHFFFAOYSA-N 0.000 description 1
- 229960000074 biopharmaceutical Drugs 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 238000002425 crystallisation Methods 0.000 description 1
- 230000008025 crystallization Effects 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 239000003814 drug Substances 0.000 description 1
- 229940079593 drug Drugs 0.000 description 1
- 239000000428 dust Substances 0.000 description 1
- 238000005538 encapsulation Methods 0.000 description 1
- 238000001704 evaporation Methods 0.000 description 1
- 230000008020 evaporation Effects 0.000 description 1
- 239000012530 fluid Substances 0.000 description 1
- 238000002347 injection Methods 0.000 description 1
- 239000007924 injection Substances 0.000 description 1
- 238000011900 installation process Methods 0.000 description 1
- 230000010354 integration Effects 0.000 description 1
- 229910001338 liquidmetal Inorganic materials 0.000 description 1
- 239000004005 microsphere Substances 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 231100000956 nontoxicity Toxicity 0.000 description 1
- 238000005192 partition Methods 0.000 description 1
- 229920002223 polystyrene Polymers 0.000 description 1
- 238000007781 pre-processing Methods 0.000 description 1
- 238000003860 storage Methods 0.000 description 1
- 238000003786 synthesis reaction Methods 0.000 description 1
- 238000001029 thermal curing Methods 0.000 description 1
- 230000000007 visual effect Effects 0.000 description 1
Images
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01L—CHEMICAL OR PHYSICAL LABORATORY APPARATUS FOR GENERAL USE
- B01L3/00—Containers or dishes for laboratory use, e.g. laboratory glassware; Droppers
- B01L3/50—Containers for the purpose of retaining a material to be analysed, e.g. test tubes
- B01L3/502—Containers for the purpose of retaining a material to be analysed, e.g. test tubes with fluid transport, e.g. in multi-compartment structures
- B01L3/5027—Containers for the purpose of retaining a material to be analysed, e.g. test tubes with fluid transport, e.g. in multi-compartment structures by integrated microfluidic structures, i.e. dimensions of channels and chambers are such that surface tension forces are important, e.g. lab-on-a-chip
- B01L3/502707—Containers for the purpose of retaining a material to be analysed, e.g. test tubes with fluid transport, e.g. in multi-compartment structures by integrated microfluidic structures, i.e. dimensions of channels and chambers are such that surface tension forces are important, e.g. lab-on-a-chip characterised by the manufacture of the container or its components
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D19/00—Degasification of liquids
- B01D19/0073—Degasification of liquids by a method not covered by groups B01D19/0005 - B01D19/0042
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D19/00—Degasification of liquids
- B01D19/02—Foam dispersion or prevention
Abstract
The invention discloses a portable vacuum-pumping PDMS bubble device and method, adopting a portable vacuum cup, pouring PDMS after stirring uniformly into a pouring container equipped with a micro-channel template, placing the PDMS into the vacuum cup, covering a double-layer vent cover, pumping outwards through a piston at the lower part of the vacuum cup to generate a larger negative pressure environment inside the vacuum cup, wherein air bubbles in PDMS gradually float to the top of the PDMS liquid surface due to the influence of density, when the phenomenon is observed through the cup body, rotating the top cover of the vacuum cup to align small holes of the vacuum cup with the small holes of the vent cover and then releasing the internal negative pressure environment, taking out the pumped pouring container containing PDMS solution, blowing off the small bubbles which previously float to the top of the PDMS liquid surface by using an ear washing ball, heating by using a heating table to complete the solidification of the PDMS solution, and finally performing the membrane removal treatment on the prepared micro-fluidic channel by using metal tweezers, finally, performing key summation to complete the preparation process of the portable PDMS microfluidic channel without any air bubbles.
Description
Technical Field
The invention belongs to the field of preparation of a Polydimethylsiloxane (PDMS) micro-fluidic chip based on soft lithography, and particularly relates to a method for removing bubbles of a PDMS mixed solution by manual piston air suction, wherein a large amount of bubbles can be generated in the PDMS mixed solution prepared in a micro-channel pouring process due to air dissolution.
Background
In recent decades, microfluidic technology (Microfluidics) has attracted much attention for its potential applications in various fields such as drug encapsulation, material synthesis, crystallization and chemical reactions, and it is a manipulation of nanoliters to picoliters (10) in micron-scale structures -9 -10 -12 L) technology and science of volumetric fluids. With the increasing demand for miniaturization and integration of novel detection devices in the fields of biomedicine and high-end manufacturing, the efficient and convenient preparation technology of the microfluidic chip is expected to solve the industrial pain. The current microfluidic fabrication process generally includes two methods, one is the fabrication of glass capillary based microchannels, and the other is the fabrication of soft lithography based Polymethylsilane (PDMS) microchannels. Although the preparation method of the microchannel of the glass capillary has higher flexibility, the alignment is difficult, the stability of the device is poorer, and the batch production is difficult to realize; the soft lithography-based PDMS microchannel preparation method adopts mature template pouring, can quickly obtain a microchannel with accurate stability and size according to different templates, and has wide prospect in large-scale mass production. The PDMS prepolymer has outstanding light transmission, safety, non-toxicity, low thermal curing temperature, high strength and elastic modulus close to human skin, has important value in the field of microfluidics, and has more and more prominent application advantages in the fields of flexible electronics and biopharmaceuticals.
When the micro-channel is prepared by adopting the soft lithography-based Polymethylsilane (PDMS), firstly, a precured PDMS precursor (glue A) and a crosslinking agent (glue B) need to be weighed, mixed and stirred according to the mass ratio of 10:1, and usually, only 25 g of PDMS mixed liquid is needed when the channel is poured. But the process of stirring was accompanied by the process of dissolution of air in the PDMS stirring liquid. After dissolution, a large number of microbubbles are generated, usually with diameters less than 1mm, and the human eye cannot directly observe the specific bubble morphology, but can see that the clear solution turns milky white. If the PDMS prepolymer is not subjected to air exhaust treatment, the channel poured out can seriously reduce the channel strength because bubbles obstruct microscopic observation and generation and control of micro-droplets. When the liquid that contains the bubble was located in the very low region of an absolute pressure, the bubble can rapid evaporation or free, through the effect come-up to the liquid surface of buoyancy, because the effect of liquid level tension this moment, final bubble can gather in PDMS solution surface, thereby adopts the aurilave to blow through the bubble of liquid level department this moment and realize the effect of getting rid of the bubble.
At present, in order to eliminate bubbles in PDMS solution, a vacuum drying oven is mainly adopted to carry out air extraction treatment on the prepolymer, but the experimental equipment is often large in size and expensive; to above problem, provide a device of portable evacuation PDMS bubble, can realize the function that this instrument possessed through manual pumping, the overall device is removable completely moreover, does benefit to and washs and assemble, and the small in size simple structure satisfies the laboratory to the demand of bleeding of easily producing a large amount of bubble solutions.
Disclosure of Invention
The invention aims to design a portable device for vacuumizing PDMS bubbles, and solves the problem of removing solution bubbles during pouring of the traditional microfluidic PDMS microchannel.
The technical scheme adopted by the invention is a portable device for vacuumizing PDMS bubbles, which comprises three modules, wherein each part is obtained by 3D printing or machining (turning and milling); the first module is used for assembling the cup body to create a vacuum cavity; the second module is used for assembling the manual air extraction piston and realizing the adjustable positioning function, and the top of the piston is provided with a rubber sleeve, so that the PDMS solution in the cup body is not exposed, and the sealing effect is good; the third module is used for pouring the microfluidic channel, a pressure gauge ensures that a negative pressure environment meets the requirement of rapid separation of bubbles, and a pouring container and a template are used for containing PDMS solution;
a portable device for vacuumizing PDMS bubbles comprises a cup body (3), wherein internal threads are arranged on the inner wall of the top of the cup body (3), and threads are arranged at the upper position and the lower position of a through hole cover (2); the lower position of the through hole cover (2) is in threaded connection with the inner wall of the top of the cup body (3); the upper position of the through hole cover (2) is in threaded connection with the top cover (1); through holes are formed in the through hole cover (2) and the top cover (1), and air closing or ventilation is achieved through rotation alignment.
The bottom of the manual piston (8) is provided with a mounting hole of the support plate (6), and the support plate (6) and the manual piston (8) can be connected into a whole through the mounting hole; a piston rod is arranged in the middle of the manual piston (8), and a piston rubber sleeve (5) is arranged at the top of the piston rod; a pouring container (10) is arranged at the upper part of the piston rubber sleeve (5), and a PDMS solution (11) and a micro-channel template (12) are arranged in the pouring container (10);
and a piston rod of the manual piston (8) and the supporting plate (6) are provided with a plurality of fixing holes which are arranged in parallel, and a positioning square pin (7) is arranged in each fixing hole and used for fixing the position of the manual piston (8).
A vacuum chamber (4) is arranged between the upper part of the cup body (3), namely the through hole cover (2) and the pouring container (10). The side wall of the upper part of the cup body (3) is provided with a vacuum barometer (9).
Further, the micro-fluidic channel template (12) is obtained by processing a circular silicon chip through a photoetching method and is placed in the pouring container (10).
Further, the support plate (6) is connected with the manual piston (8) through the mounting hole.
Further, uniformly stirring a precured PDMS precursor, namely glue A, and a cross-linking agent, namely glue B, by using a disposable plastic spoon, taking out a manual piston (8), sleeving a piston rubber sleeve (5) on the top end of the piston, inserting two support plates (6) into two square slots at a bottom disc, fixing the two support plates by using the glue A and the glue B, inserting the manual piston (8) into the cup body (3) from the lower part, placing a pouring container (10) containing a PDMS solution (11) and a micro-channel template (12) into the cup body (3) from the upper part by using tweezers, and using the top of the manual piston (8) as a support; a vacuum barometer (9) is connected in a threaded manner in an internal threaded hole in the side wall of the cup body (3); the top of the cup body (3) is connected with the through hole cover (2) through threads, one side of the through hole cover (2) is connected with the cup body (3) through external threads, the other side of the through hole cover (2) is connected with the top cover (1) through internal threads, and through rotating the top cover (1), the through hole cover (2) and the vent hole of the top cover (1) are sealed in an unaligned mode; and finally, pulling down the manual piston (8), after the negative pressure of the barometer (9) reaches a preset value, penetrating through the two supporting plates (6) and the manual piston (8) through the positioning square pin (7) to finish fixed installation, and generating a vacuum chamber (4) on the upper part of the cup body (3).
This device has a container of pouring in that cup is inside, the microchannel template that need pour is put to its bottom, the template top covers one deck PDMS prepolymer, make the inside vacuum chamber that produces of cup through manual pull-down piston, promote the inside bubble come-up of PDMS solution to the surface, pull-down piston blocks through two backup pads and a location square pin, the manometer has been inserted to vacuum chamber position wall in addition, whether satisfy the requirement with the pressure when guaranteeing inside pressurize, pressurize 40min can realize degassing process usually.
The portable vacuum PDMS bubble device is divided into seven parts: 1) pouring the PDMS mixed solution into a pouring container with a microchannel template at the bottom and filling the pouring container into the cup body; 2) creating a vacuum cavity by pumping air through the piston and checking whether the pressure gauge meets the vacuum requirement; 3) the positioning square pin is blocked to ensure that the solution bubbles float to the surface in a continuous negative pressure environment; 4) rotating the vent hole to release negative pressure in the cup body and pouring out PDMS solution; 5) taking out the pouring container from the interior of the cup body; 6) micro bubbles on the surface of the PDMS mixed solution in the pouring container are blown through an ear washing ball and heated for 60min at a heating table at 80 ℃ to finish curing; 7) separating the poured PDMS micro-channel, the pouring container and the template by using tweezers.
It should be noted that the negative pressure environment and the open environment can be created inside the cup body by rotating the vent cover to align the small hole with the vent hole of the top cover.
Compared with the prior art, the PDMS solution before and after being treated by the device and the method provided by the invention has a large amount of bubbles and is milky, the light transmission effect of the cured micro-channel of the PDMS in the pouring container can be seen to be excellent in the treatment, the micro-bubbles contained in the untreated PDMS micro-channel can be found to block the channel and obstruct the preparation of micro-droplets and the movement of particles by observing under an inverted fluorescence microscope, and the treated PDMS micro-channel has no micro-bubbles and has excellent performance.
Drawings
Fig. 1 is a module for assembling cups to create a vacuum chamber. (a) Top cover: the air vent is arranged and is in threaded fit with the through hole cover, so that two modes of closing and opening can be realized; (b) through hole cover (including front and back): the front side of the through hole cover is matched with the threads of the cup body, and the back side of the through hole cover is matched with the top cover; (c) transparent acrylic cup: the cup design has the drainage closed angle, can pour out the PDMS solution after bleeding to be furnished with one and hold the handle, follow-up productization can be at the cup lateral wall add volume scale.
Figure 2 is a block diagram for assembling a manual extraction piston and performing an adjustable positioning function. (a) A piston rubber sleeve: the rubber sleeve is matched with a disc at the top of the manual piston to realize the bottom sealing of the cup body; (b) a manual piston: the air can be pumped out from the cup body; (c) a support plate: the square holes of the device are matched with the positioning square pins to ensure that the device can continuously keep a negative pressure state; (d) positioning a square pin: the square section can ensure the stability of the support of the cup body.
Fig. 3 is a module for casting microfluidic channels: (a) micro-fluidic channel template: preparing a micro-fluidic channel template on a silicon wafer by adopting soft lithography, and customizing the micro-fluidic channel template for a laboratory or a mechanism; (b) a barometer: a pressure vacuum meter is taken as a main part and is inserted into an internal thread hole on the side wall of the vacuum cup body, 0.2 atmosphere is ensured, and the pressure is maintained for 40min optimally; (c) pouring a container: the cylindrical container is made of 304 stainless steel and is used for containing PDMS mixed solution.
Fig. 4 is an assembly schematic diagram of a portable evacuated PDMS bubble device: there is a container of pouring in the inside of the cup of device, the microchannel template that need pour is put to its bottom, the template top covers one deck PDMS prepolymer (has a large amount of bubbles), make the inside vacuum chamber (negative pressure environment) that produces of cup through manual pull-down piston, promote the inside bubble come-up of PDMS solution to the surface, pull-down piston blocks through two backup pads and a location square pin, the manometer has been inserted to vacuum chamber position wall in addition, whether the pressure satisfies the requirement when guaranteeing inside pressurize, the degassing process can be realized to pressurize usually, the integrated device is small and exquisite simple, each position all can be dismantled and wash, therefore, the carrier wave prepaid electric energy meter is low in cost.
FIG. 5 is a schematic diagram of the principle of the portable vacuum PDMS bubble device: the integral structure comprises that 1, PDMS mixed solution is poured into a pouring container with a micro-channel template at the bottom and is filled in a cup body; 2. creating a vacuum cavity by pumping air through the piston and checking whether the pressure gauge meets the vacuum requirement; 3. the positioning square pin is blocked to ensure that the solution bubbles float to the surface in a continuous negative pressure environment; 4. rotating the vent hole to release negative pressure in the cup body and pouring out PDMS solution; 5. taking out the pouring container from the interior of the cup body; 6. micro bubbles on the surface of the PDMS mixed solution in the pouring container are blown through an ear washing ball and heated for 60min at a heating table at 80 ℃ to finish curing; 7. separating the poured PDMS micro-channel, the pouring container and the template by using tweezers.
FIG. 6 is a schematic view of the through hole cover closing and opening: the closed and open environment within the cup cavity is created by rotating the vent cap.
FIG. 7 is a comparison of the internal bubbles of the PDMS mixed solution before and after evacuation: a large amount of bubbles are in the solution before vacuumizing and are milky, the bubbles float to the surface of the solution after vacuumizing, and the bubbles are blown by an aurilave so as to be completely removed.
FIG. 8 is a PDMS microchannel observed under an inverted fluorescence microscope: the left and right figures show the microchannel (including the channel blocked by bubbles) which is not processed by the method of the device and the microchannel obtained by the method of the device respectively, and the good visual field of the channel can be seen without bubbles or impurities which obstruct the flow of the microfluid.
Fig. 9 is a sectional view (front view and side view) of a portable vacuum-pumping PDMS bubble device, which is small and novel, easy to realize mass production, detachable, simple in structure and low in cost.
Detailed Description
The invention designs a portable vacuumizing PDMS bubble device, which solves the problem of removing solution bubbles during pouring of the traditional microfluidic PDMS micro-channel. The device comprises three modules, and each part can be obtained by 3D printing or machining (turning, milling): one is a module for assembling the cup body to create a vacuum chamber, as shown in fig. 1; the second is a module used for assembling the manual air extraction piston and realizing the adjustable positioning function, as shown in fig. 2, the top of the piston is provided with a rubber sleeve, so that the PDMS solution in the cup body is ensured not to be exposed, and the sealing effect is good; thirdly, a module for pouring the microfluidic channel, a pressure gauge ensures that the negative pressure environment meets the requirement of rapid bubble separation, and a pouring container and a template are used for containing PDMS solution, as shown in figure 3; this device has a container of pouring in that cup is inside, the microchannel template that needs to pour is put to its bottom, the template top covers one deck PDMS prepolymer, make the inside vacuum chamber that produces of cup through manual pull-down piston, promote the inside bubble of PDMS solution to come up to the surface, pull-down piston blocks through two backup pads and a location square pin, the manometer has been inserted to vacuum chamber position wall in addition, whether meet the requirement with the pressure when guaranteeing inside pressurize, the degasification process can be realized to pressurize 40min usually, its assembly diagram is as shown in fig. 4.
The portable vacuum PDMS bubble device is divided into seven parts: pouring the PDMS mixed solution into a pouring container with a microchannel template filled at the bottom, filling the pouring container into a cup body, creating a vacuum cavity by pumping air through a piston, checking whether a pressure gauge meets vacuum requirements, positioning a square pin to be locked to ensure that a continuous negative pressure environment enables solution bubbles to float to the surface, rotating a vent hole to release negative pressure inside the cup body and pouring out the PDMS solution, taking out the pouring container from the inside of the cup body, blowing micro bubbles on the surface of the PDMS mixed solution inside the pouring container through a aurilave, heating the micro bubbles on a heating table at 80 ℃ for 60min to complete solidification, and separating the poured PDMS microchannel, the pouring container and the template by using tweezers, wherein the schematic diagram is shown in figure 5. It should be noted that the negative pressure environment and the open environment can be created inside the cup by rotating the vent cover to align its small holes with the vent holes in the top cover, as shown in fig. 6. The PDMS solution before and after being treated by the apparatus and method is shown in fig. 7, wherein the PDMS solution before and after being treated contains a large amount of bubbles and is milky white, the light transmission effect of the cured micro-channel of PDMS in the casting container can be seen to be excellent after treatment, and the micro-bubbles contained in the untreated PDMS micro-channel can be found to block the channel and obstruct the preparation of micro-droplets and the movement of particles when observed under an inverted fluorescence microscope, while the treated PDMS micro-channel does not contain any micro-bubbles and has excellent performance, as shown in fig. 8. Finally, a front sectional view and a side sectional view of the entire device are shown in fig. 9.
Examples
At present, a vacuum drying oven is mainly adopted to perform air extraction treatment on the prepolymer for removing bubbles in the PDMS solution, but the experimental equipment is often large in size, expensive and difficult to carry; aiming at the problems, a portable vacuumizing PDMS bubble device and an improved preparation scheme of a microfluidic chip are provided, the actual requirement of a laboratory for removing a large amount of bubbles from a PDMS solution is met, the prepared microfluidic PDMS microchannel is highly smooth and transparent and free of any bubble impurity, and microfluidic experiments such as liquid drops, cells, particles, liquid metal and the like can be carried out.
Wherein, the connection relation of all parts of the portable vacuum PDMS bubble device is as follows, a micro-fluidic channel template (12) required by the experiment is obtained on a round silicon chip by photoetching processing, the micro-fluidic channel template is put into a pouring container (10), a precured PDMS precursor (A glue) and a cross-linking agent (B glue) are uniformly stirred and poured on the surface of the micro-channel template by a disposable plastic spoon until the pouring container is completely poured, at the moment, a manual piston (8) is taken out, a piston rubber sleeve (5) is sleeved on a disc at the top end of the piston, two support plates (6) are inserted into two square slotted holes at a disc at the bottom and fixed by AB glue, the manual piston is inserted into a cup body (3) from the lower part, the pouring container containing PDMS solution (11) and the micro-channel template (12) is put into the cup body from the upper part by tweezers, the top of the manual piston is used as a support, a vacuum barometer (9) is in threaded connection in an inner threaded hole with the side wall of the cup body with the diameter of 3mm, at this moment, the top of the cup body is connected with the through hole cover (2) through a thread, the through hole cover is connected with the cup body through an external thread on one side of the through hole cover, the top cover (1) is connected with an internal thread on the other side, the through hole cover and the top cover vent hole do not achieve a sealing effect on the through rotating the top cover, the hand-operated piston is pulled down at last, after the negative pressure of the barometer reaches a proper value, the two supporting plates and the hand-operated piston are penetrated through a square pin to complete clamping and fixing, and at this moment, a vacuum cavity (4) is generated inside the cup body. The final assembly is shown schematically in fig. 4.
On the basis of the device assembly scheme, the specific scheme for manufacturing the PDMS microfluidic chip by the invention is as follows:
the first step is as follows: microfluidic channel template pretreatment
The microchannel template required by the experiment is obtained by processing on a smooth silicon wafer through a photoetching method, and as with the traditional process, if microchannels with different shapes need to be processed on one template, a dividing line is reserved when the design needs to be paid attention to.
The second step is that: pouring PDMS mixed solution
Putting the processed micro-channel template into a pouring container, and pouring a pre-cured PDMS precursor (glue A) and a cross-linking agent (glue B) by a disposable plastic spoon according to a weight ratio of 10:1, uniformly stirring and pouring the mixture on the surface of the micro-channel template until a pouring container is completely poured, wherein the PDMS solution obtained by stirring is milky white due to a large amount of bubbles. A plurality of partition plates can be arranged in the pouring container (cylindrical container) so as to meet the requirement of simultaneously pouring different template micro-channels.
The third step: assembling hand piston
Take out manual piston, sheathe piston rubber sleeve in with piston top disc department, the realization process that follow-up bleeding produced the vacuum chamber has been guaranteed to the good adherence leakproofness of rubber products, in addition, obtain two square slotted holes through the turning in piston bottom disc department, can insert two backup pads that the pre-processing is good, the backup pad is opened has three square hole to the size of adjustment cup inner chamber negative pressure, insert the back, glue through AB and glue in cooperation hole department and seal, prevent that follow-up installation process backup pad from dropping.
The fourth step: assembling cup body and pressure gauge installation
The manual piston is inserted into the cup body from the lower part, the pouring container filled with the PDMS solution and the micro-channel template is placed into the cup body from the upper part through the tweezers, the top of the manual piston is used as a support, the vacuum pressure gauge is connected into an inner threaded hole with the diameter of 3mm on the side wall of the cup body in a threaded mode, the pressure gauge can directly read the negative pressure value of a vacuum cavity in the cup body, and corresponding pressure maintaining time is selected.
The fifth step: cover mounting and sealing
After the cup body is assembled, the internal thread at the top of the cup body is connected with the external thread of the through hole cover, one side of the through hole cover is provided with the external thread, the other side of the through hole cover is provided with the internal thread, the internal thread of the through hole cover is connected with the top cover, and the top cover can be rotated to ensure that the through hole cover and the top cover vent hole do not achieve the sealing effect.
And a sixth step: pull-down piston and fixed pressure maintaining
Through hand drop-down manual piston, realize that cup inside presents complete negative pressure state, the vacuum pressure gauge pointer of cup lateral wall installation this moment takes place to deflect, when it indicates 0.4 atmospheric pressure, run through two backup pads and manual piston through a square pin, accomplish the card process of dying, the square pin can play stable supporting effect to whole cup, wherein negative pressure intensity and pressurize time present the certain relation, this part can set up different draw-in groove positions in backup pad department, realize negative pressure fender position control, generally the stronger negative pressure is, the pressurize time is shorter, when 0.4 atmospheric pressure, need pressurize 40min can realize that the microbubble in the PDMS solution is whole to float on the surface, because the cup is transparent ya keli material system, can directly observe the bubble come-up effect.
The seventh step: pressure relief and surface micro-bubble treatment of PDMS solution
The cap is rotated to connect the hole with the cap hole to complete the pressure release process, the principle is shown in fig. 6. Then the top cover and the through hole cover are opened, the pouring container is taken out from the inside by using tweezers and placed on a flat desktop, the ear washing ball is pressed by a hand, micro bubbles on the surface of the PDMS solution in the whole pouring container are blown open, the process of completely eliminating the bubbles is completed, and the whole PDMS solution is observed to be completely transparent under a spotlight at the moment, as shown in the right picture of fig. 7.
The eighth step: heating curing and demolding
And (3) placing the whole pouring container on a heating table for constant-temperature heating, wherein the heating is usually carried out at 80 ℃ for 60min, after the heating is finished, the bubble-removed PDMS mixed solution is completely cured, at the moment, the PDMS microchannel, the microchannel template and the pouring container are separated by the tip of the tweezers to realize the demolding process, and traceless glue is adopted for storage to prevent dust pollution.
The ninth step: pouring and bonding bottom plate
The bottom plate pouring process is similar to the micro-channel pouring process, and the micro-channel template is directly poured without being placed in the pouring container. And bonding the PDMS micro-channel and the bottom plate by using an ultraviolet plasma bonding machine, and obtaining the smooth and transparent micro-fluidic channel without any air bubbles after bonding.
The tenth step: microscopic observation
According to the requirements of microfluidic experiments, the prepared microfluidic channel is placed under an inverted fluorescence microscope for observation, a high-precision micro-injection pump is injected into each phase channel of the PDMS microchannel through a PTEF (Polytetrafluoroethylene) tube, whether a plurality of high-precision micro-injection pumps are needed or not can be determined according to the requirements of the actual experiments, a single injection pump is adopted in the graph 8 to introduce 5-micron polystyrene microspheres in a needle tube into the PDMS microchannel for observation, and the micro-channel which is not prepared by adopting the scheme has more bubbles and influences shooting and particle motion tracks.
Compared with the prior art, the device directly improves the traditional bubble removing method of the vacuum drying oven adopted by the existing PDMS microchannel processing, the prepared PDMS microchannel does not have any micro bubble, and the stability and experimental observation of the microfluidic device are easy to guarantee. Compare in traditional vacuum drying oven, this device structure is simple and convenient quick detachable clearance, easily productization batch production and popularization. The materials and appliances adopted by the device and the scheme are common materials in daily life, and the device is low in cost and easy to prepare.
Claims (4)
1. The utility model provides a device of portable evacuation PDMS bubble which characterized in that: comprises a cup body (3), wherein the inner wall of the top of the cup body (3) is provided with internal threads, and the upper and lower positions of a through hole cover (2) are both provided with threads; the lower position of the through hole cover (2) is in threaded connection with the inner wall of the top of the cup body (3); the upper position of the through hole cover (2) is in threaded connection with the top cover (1); through holes are formed in the through hole cover (2) and the top cover (1), and air closing or ventilation is achieved through rotation alignment;
the bottom of the manual piston (8) is provided with a mounting hole of the support plate (6), and the support plate (6) and the manual piston (8) can be connected into a whole through the mounting hole; a piston rod is arranged in the middle of the manual piston (8), and a piston rubber sleeve (5) is arranged at the top of the piston rod; a pouring container (10) is arranged at the upper part of the piston rubber sleeve (5), and a PDMS solution (11) and a micro-channel template (12) are arranged in the pouring container (10);
a piston rod of the manual piston (8) and the support plate (6) are provided with a plurality of fixing holes which are arranged in parallel, and positioning square pins (7) are arranged in the fixing holes and used for fixing the position of the manual piston (8);
a vacuum chamber (4) is arranged between the upper part of the cup body (3), namely the through hole cover (2) and the pouring container (10); the side wall of the upper part of the cup body (3) is provided with a vacuum barometer (9).
2. A portable evacuated PDMS bubble apparatus according to claim 1, wherein: the micro-fluidic channel template (12) is obtained by processing a circular silicon chip through a photoetching method and is placed in the pouring container (10).
3. A portable evacuated PDMS bubble apparatus according to claim 1, wherein: the supporting plate (6) is connected with the manual piston (8) through the mounting hole.
4. A portable evacuated PDMS bubble apparatus according to claim 1, wherein: the implementation process of the device is as follows: uniformly stirring a precured PDMS precursor, namely glue A and a cross-linking agent, namely glue B, by using a disposable plastic spoon, taking out a manual piston (8), sleeving a piston rubber sleeve (5) on the top end of the piston, inserting two support plates (6) into two square slotted holes at a bottom disc, fixing the piston by using the glue A and the glue B, then inserting the manual piston (8) into a cup body (3) from the lower part, putting a pouring container (10) containing a PDMS solution (11) and a microchannel template (12) into the cup body (3) from the upper part by using tweezers, and taking the top of the manual piston (8) as a support; a vacuum barometer (9) is connected in a threaded manner in an internal threaded hole in the side wall of the cup body (3); the top of the cup body (3) is connected with the through hole cover (2) through threads, one side of the through hole cover (2) is connected with the cup body (3) through external threads, the other side of the through hole cover (2) is connected with the top cover (1) through internal threads, and through rotating the top cover (1), the through hole cover (2) and the vent hole of the top cover (1) are sealed in an unaligned mode; and finally, pulling down the manual piston (8), after the negative pressure of the barometer (9) reaches a preset value, penetrating through the two supporting plates (6) and the manual piston (8) through the positioning square pin (7) to finish fixed installation, and generating a vacuum chamber (4) on the upper part of the cup body (3).
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210427544.0A CN114798022B (en) | 2022-04-21 | Device and method for portable vacuumizing of PDMS (polydimethylsiloxane) bubbles |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210427544.0A CN114798022B (en) | 2022-04-21 | Device and method for portable vacuumizing of PDMS (polydimethylsiloxane) bubbles |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN114798022A true CN114798022A (en) | 2022-07-29 |
| CN114798022B CN114798022B (en) | 2024-04-19 |
Family
ID=
Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103068308A (en) * | 2010-07-16 | 2013-04-24 | 第七感生物系统有限公司 | Low-pressure environment for fluid transfer devices |
| CN104549583A (en) * | 2014-12-26 | 2015-04-29 | 华南师范大学 | Manufacturing method of microfluidic chips |
| CN105779699A (en) * | 2016-03-28 | 2016-07-20 | 上海大学 | Method for removing metallic inclusions through dissolved gas float process and pressurizing vacuum induction furnace refining device |
| CN206068526U (en) * | 2016-10-12 | 2017-04-05 | 胡琪 | Evacuation bowl cover |
| CN106660045A (en) * | 2014-02-05 | 2017-05-10 | 斯利普奇普公司 | Sample preparation module with stepwise pressurization mechanism |
| CN209080623U (en) * | 2018-09-04 | 2019-07-09 | 乐美益 | Vacuum cup and its vacuumize cup lid |
| CN110227566A (en) * | 2019-07-15 | 2019-09-13 | 重庆大学 | A kind of PDMS Micro-fluidic chip die clone method |
| CN110921109A (en) * | 2019-12-31 | 2020-03-27 | 佛山市梵美科技有限公司 | Portable vacuum-pumping cup and vacuum-pumping cup cover |
| CN110975954A (en) * | 2019-12-23 | 2020-04-10 | 北京工业大学 | Device is pour to PDMS micro-fluidic chip secondary |
| CN214085715U (en) * | 2020-12-28 | 2021-08-31 | 杨明祥 | Electric vacuum-pumping device |
Patent Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103068308A (en) * | 2010-07-16 | 2013-04-24 | 第七感生物系统有限公司 | Low-pressure environment for fluid transfer devices |
| CN106660045A (en) * | 2014-02-05 | 2017-05-10 | 斯利普奇普公司 | Sample preparation module with stepwise pressurization mechanism |
| CN104549583A (en) * | 2014-12-26 | 2015-04-29 | 华南师范大学 | Manufacturing method of microfluidic chips |
| CN105779699A (en) * | 2016-03-28 | 2016-07-20 | 上海大学 | Method for removing metallic inclusions through dissolved gas float process and pressurizing vacuum induction furnace refining device |
| CN206068526U (en) * | 2016-10-12 | 2017-04-05 | 胡琪 | Evacuation bowl cover |
| CN209080623U (en) * | 2018-09-04 | 2019-07-09 | 乐美益 | Vacuum cup and its vacuumize cup lid |
| CN110227566A (en) * | 2019-07-15 | 2019-09-13 | 重庆大学 | A kind of PDMS Micro-fluidic chip die clone method |
| CN110975954A (en) * | 2019-12-23 | 2020-04-10 | 北京工业大学 | Device is pour to PDMS micro-fluidic chip secondary |
| CN110921109A (en) * | 2019-12-31 | 2020-03-27 | 佛山市梵美科技有限公司 | Portable vacuum-pumping cup and vacuum-pumping cup cover |
| CN214085715U (en) * | 2020-12-28 | 2021-08-31 | 杨明祥 | Electric vacuum-pumping device |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN103231518B (en) | Polydimethylsiloxane array micropore film preparation method | |
| CN109603935B (en) | Micro-fluidic chip processing method based on plug-in capillary | |
| CN108636464A (en) | A kind of drop micro-fluidic chip, molding machine and preparation method thereof | |
| CN113388517B (en) | Biological culture micro-fluidic chip suitable for assembling microgravity gyroscope and cell culture method thereof | |
| Beyer et al. | 3D alginate constructs for tissue engineering printed using a coaxial flow focusing microfluidic device | |
| EP2408900A2 (en) | Microorganism culture device and method of operation thereof | |
| US9658240B2 (en) | Microfluidic device with holding interface, and methods of use | |
| CN104998702A (en) | Preparation method of PDMS microfluidic chip based on liquid composite molding method | |
| CN106064261A (en) | The System and method for of micro-pit array Electrolyzed Processing based on magnetic PDMS mask | |
| CN114798022A (en) | Portable device and method for vacuumizing PDMS bubbles | |
| CN105277724A (en) | Micro-fluidic chip device and preparation method thereof | |
| CN114798022B (en) | Device and method for portable vacuumizing of PDMS (polydimethylsiloxane) bubbles | |
| CN108525622A (en) | A kind of reaction of high order micro fluidic device and its prepare applications to nanostructures | |
| CN102212458A (en) | Variable pitch microcolumn array-based cell sorting structure and manufacturing method thereof | |
| CN208288041U (en) | A kind of drop micro-fluidic chip and molding machine | |
| CN106079174A (en) | PDMS microwell array method for preparing template | |
| CN209478729U (en) | Micropin mold and mold | |
| CN105352857A (en) | Structure, preparation method and observation method of wetting chip for observing wetting microscopic behavior | |
| CN209791576U (en) | Liquid drop mass production device | |
| CN105910878B (en) | A kind of device removed for gas in microfluidic channel | |
| CN103146573A (en) | Artery blood vessel simulation microfluidic device and use thereof | |
| CN108393102A (en) | A kind of micro-fluidic chip and preparation method of achievable positive side observation simultaneously | |
| CN209784162U (en) | fixing device for red blood cell super-resolution imaging | |
| CN111269572B (en) | Preparation method of polydimethylsiloxane wedge-shaped porous film | |
| CN108313977B (en) | A kind of preparation method of expansible thimble tube micro-fluidic chip |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant |