Process for preparing high polymer micro-flow control chips

[0048] Example 1:

[0049] (1) Fabrication of cover sheet: A stainless steel column with a diameter of 2mm and a height of 2mm is placed on a specific position of the smooth glass, and the mixture of PMMA monomer and benzoyl peroxide (weight ratio is 1000: 5) is pre-processed. After polymerization and degassing, it was transferred to the glass, the air was removed and sealed, and after 24 hours of low temperature polymerization (45°C) and two hours of high temperature polymerization (90°C), the release template was taken out at 40°C. (2) Metal negative plate production: the titanium gold plate is rinsed with water, placed in the lotion for one day, to remove the surface oil, rinse with distilled water, and dry. Spin glue (BP-213) on the titanium gold plate and pre-bake, the pre-bake time is 5 minutes, the temperature is 90 degrees. Place the mask with the microchannel network on the photoresist, expose to UV light for 1 minute, and then use 0.5wt% NaOH solution to develop at 15°C for 10 minutes to remove the light outside the microchannel network on the titanium gold plate. The resist is heat-baked at 120 degrees for 1 hour. The titanium gold plate was etched at room temperature with ferric trichloride acidic etching solution for 30 minutes, and the content of ferric chloride in the etching solution was 35wt%; thus a titanium gold negative plate with convex microchannel patterns was formed, and the depth of the microchannels was 20 Micrometers, the width is 90 micrometers.

[0050] (3) Fabrication of PMMA substrate containing microchannel polymer: the size of the relief produced by the titanium negative plate of step (2) corresponds to the size of the microchip separation channel, PMMA monomer and benzoyl peroxide Mix with a weight ratio of 1000:5, pre-polymerize at 80°C to a viscosity of 80Pa.s, quickly cool down to 25°C, degas under vacuum at a pressure of 0.06Mpa for about half an hour, and pour the titanium gold in step (2) The negative plate was sealed at 45°C for low-temperature polymerization for 24 hours, then slowly heated to 90°C for high-temperature treatment for 2 hours, and slowly cooled to 40°C for demolding to obtain a high polymer microfluidic chip substrate.

[0051] (4) Close the cover sheet and the base sheet, and heat at 120 degrees for 10 minutes to bond. A PMMA chip with a length of 5 cm, a width of 5 cm, and a thickness of 4 mm, a separation channel length of 3 cm, a channel width of 90 μm, and a channel depth of 20 μm was obtained.

[0052] Example 2:

[0053] (1) Metal negative plate production: the stainless steel plate is rinsed with water, placed in the lotion for one day, to remove the surface oil, rinse with distilled water, and dry. Spin glue (RZJ-390) on the stainless steel plate and pre-bake, the pre-bake time is 1.5 minutes, and the temperature is 100 degrees. Place the mask with the microchannel network pattern on the photoresist, expose to ultraviolet light for 20 seconds, then put the metal plate in 0.4wt% NaOH solution, develop at 25°C for 5 minutes, and remove the microchannels from the stainless steel plate. The photoresist outside the channel network is heat-baked at 130 degrees for half an hour. The stainless steel plate is etched with an acidic ferric chloride solution at 50°C for 10 minutes. The ferric chloride content in the etching solution is 25wt%, and the etching solution contains 0.2wt% quaternary ammonium salt corrosion inhibitor. Thus, a stainless steel negative plate with a convex microchannel pattern is formed. The depth of the microchannel is about 20 microns and the width is 100 microns.

[0054] (2) Production of PMMA substrate containing microchannel polymer: the size of the relief produced by the stainless steel negative plate in step (1) corresponds to the size of the microchip separation channel, PMMA monomer and azobisisobutyronitrile Mix with a weight ratio of 1000:0.6, pre-polymerize at 75°C to a viscosity of 70Pa.s, then quickly cool it down to 20°C, degas under vacuum at a pressure of 0.09Mpa for about half an hour, and pour into the stainless steel in step (1). The plate was sealed at 45°C for low-temperature polymerization for 15 hours, then slowly heated to 90°C for high-temperature treatment for 2 hours, and slowly cooled to 40°C for demolding to obtain a polymer microfluidic chip substrate.

[0055] (3) Fabrication of the cover sheet: Place a stainless steel column with a diameter of 2mm and a height of 2mm on a clean stainless steel plate at a specific position, and mix the PMMA monomer and azobisisobutyronitrile in a weight ratio of 1000:0.6. After pre-polymerization and degassing, the mixture is transferred to the stainless steel plate, the air is removed and sealed, and after 15 hours of low temperature polymerization (45°C) and two hours of high temperature polymerization (90°C), it is taken out and peeled off at 40°C. template.

[0056] (4) Close the cover sheet of step (3) and the base sheet of step (1), and heat at 120 degrees for 10 minutes to bond. A PMMA chip with a channel width of 100 microns and a channel depth of 20 microns is obtained. Example 3:

[0056] (4) Close the cover sheet of step (3) and the base sheet of step (1), and heat at 120 degrees for 10 minutes to bond. A PMMA chip with a channel width of 100 microns and a channel depth of 20 microns is obtained. Example 3:

[0057] (1) Metal negative plate production: the stainless steel plate is rinsed with water, placed in the lotion for one day, to remove the surface oil, rinse with distilled water, and dry. Adopt the screen printing technology to apply glue JL-SR1000 on the stainless steel plate and pre-bake, the pre-bake time is 30 minutes, and the temperature is 80 degrees. Place the mask plate with the microchannel network pattern on the photoresist, expose to ultraviolet light for 20 seconds, and then put the metal plate in 0.2wt% Na 2 CO 3 In the solution, develop at 25°C for 5 minutes, remove the photoresist outside the microchannel network on the stainless steel plate, and heat-bake at 120°C for 15 minutes. The stainless steel plate is etched with an acidic ferric chloride solution at 50°C for 10 minutes. The ferric chloride content in the etching solution is 25wt%, and the etching solution contains 0.2wt% quaternary ammonium salt corrosion inhibitor. Thus, a stainless steel negative plate with a convex microchannel pattern is formed. The depth of the microchannel is about 20 microns and the width is 100 microns.

[0058] (2) Production of polycarbonate substrate containing microchannel high polymer: using the metal negative plate produced by the method in step (1), the polycarbonate microfluidic substrate is produced by the hot stamping molding method. The specific condition is that the metal negative plate and the polycarbonate plate are clamped with a 5 mm thick flat and smooth mirror stainless steel plate, put in a press to pressurize, keep the pressure above 15Mpa, and then put the system into the heating furnace Medium heating, after staying at 150°C for 10 minutes, stop heating, and after the furnace temperature is cooled to below 60°C, the mold is opened and the molded polymer is taken out to prepare a polycarbonate microfluidic chip substrate.

[0059] (3) Fabrication of cover sheet: A polycarbonate sheet with a thickness of 2 mm was purchased, and a liquid tank was drilled at a specific position as the chip with a hole diameter of 2 mm.

[0060] (4) Thermal bonding of substrate and cover sheet: After the polycarbonate substrate and cover sheet are ultrasonically cleaned with deionized water, the substrate and cover sheet are closed and thermally bonded at 130 degrees for 10 minutes to obtain the width of the microchannel A polycarbonate chip of 100 microns with a channel depth of 20 microns.