Polymer micro-needle array chip, preparation process and use thereof

A method for preparing a polyacrylamides polymer comprising the steps of:

• S-1, adding an organic solvent, water and acrylamide monomer in prescribed amounts into a reactor equipped with a stirring device;
• the organic solvent comprising an alcoholic solvent and a ketonic solvent;
• the alcoholic solvent being one or more selected from the group consisting of methanol, ethanol, n-propanol, isopropanol, n-butanol;
• the alcoholic solvent being present in the reaction system in amount of not less than 60 vol %;
• the ketonic organic solvent being one or more selected from the group consisting of acetone, butanone, methyl isobutyl ketone, cyclohexanone;
• the ketonic solvent being present in the reaction system in amount of not more than 25 vol %;
• water being present in the reaction system in amount of not more than 25 vol %;
• the initial concentration of the acrylamide monomer in the reaction system being in range of 0.1-3 mol/L;
• S-2, introducing the high purity nitrogen into the reactor of reaction system comprising the solvent, water and acrylamide monomer to remove oxygen, stirring, and rising the temperature of the reaction system up to the target temperature in range of 30-85° C.;
• S-3, adding the initiator into the reaction system when the temperature reaches the target temperature, with stirring and introducing the nitrogen;
• the initiator being an azo initiator or peroxide;
• the azo initiator being one or more selected from a group consisting of 2,2-azobisisobutyronitrile, 2,2′-azobisisoheptonitrile, 2,2′-azobis[2-methylpropionamidine]dihydrochloride, diisopropyl 2,2′-azobisbutyrate, dimethyl 2,2′-azobis(2-methylpropionate);
• the peroxide being one or more selected from the group consisting of ammonium persulfate, sodium persulfate, potassium persulfate, tertiary butyl peroxide, dicumyl peroxide and benzoyl peroxide;
• preferably, the initiator further comprising a reducing agent;
• more preferably, the reducing agent being one or two selected from a group consisting of sodium bisulfite or sodium metabisulfite;
• the amount of the initiator being in range of 0.01-1 wt % of the acrylamide monomer;
• S-4, after the addition of the initiator, keeping the target temperature for 8-30 hours with stirring and introducing the nitrogen;
• the target temperature being in range of 30-85° C.;
• S-5, after the reaction, vacuum filtering a solid-liquid mixture in the reactor, then drying the resultant solid product at the temperature in range of 30-70° C.;
• S-6, dissolving the resultant dry product in water completely, adding the organic solvent which dissolves only the acrylamide monomer not the polymerization product to re-precipitate for removing the unreacted acrylamide monomer;
• the organic solvent being one or more selected from the group consisting of methanol, ethanol, n-propanol, isopropanol, n-butanol, acetone, butanone, methyl isobutyl ketone and cyclohexanone;
• repeating the steps of S-5 and S-6 for 2-4 times;
• S-7, drying the resultant product with the acrylamide monomer removed in a vacuum oven at the temperature in range of 30-70° C. for 20-50 hours to obtain the polyacrylamides polymer.

A method for preparing a polymer micro-needle array chip, comprising steps of:

• 1) preparing a prototype of micro-needle array chip, which has the same spatial features as that of the target polymer micro-needle array chip, from one or more metal material selected from the group consisting of titanium, copper, aluminum, nickel, tungsten, stainless steel, titanium alloy, nickel alloy, aluminum alloy and copper alloy;
• 2) preparing a cavity die by using the resultant prototype of metal micro-needle array chip and one or more polymer material selected from the group consisting of polyethylene, polypropylene, polylactic acid, poly(butylene succinate) and polydimethylsiloxane;
• 3) removing the prototype of micro-needle array chip from the cavity die;
• 4) mixing the polyacrylamides polymer with water to obtain an aqueous solution at the temperature in range of 10-90° C.;
• the polyacrylamides polymer being present in the aqueous solution in amount of 1-80 mass %, preferably, 10-50 mass %;
• 5) ultrasonic processing the aqueous solution prepared in step 4) to remove bubbles;
• 6) pouring the aqueous solution prepared in step 5) into the cleaned cavity die, and placing the cavity die with the aqueous solution onto a horizontal operation platform;
• preferably, placing the cavity die and the horizontal operation platform in a closed system;
• preferably, sealing the horizontal operation platform and the cavity die with a viscous liquid;
• 7) drying the aqueous solution poured into the cavity die in step 6) at the temperature in range of 20-90° C. to cure the polyacrylamides polymer of the aqueous solution in the cavity die and obtain the polymer micro-needle array chip.