Method and system for preparing tips in different shapes by micro/nano capillary uniform-internal-diameter etching

Abstract

The invention relates to a method and system for preparing tips in different shapes by micro / nano capillary uniform-internal-diameter etching, belonging to the field of microprocessing. The system is composed of a hydrofluoric acid etching cabin, a water-bath heating casing, a circulating water bath pump, a guide tube and an in-tube a pneumatic control device. The etching method comprises the following steps: double-casing etching, single-casing etching, bare-tube etching and liquid level etching. The method and system can be used for preparing uniform-internal-diameter capillary tips, of which the cone length is 1-10mm, the cone tip external diameter is 1-500 mu m and the internal diameter is 0.1-450 mu m; and the lower limit volume of the accurate liquid intake is femtoliter. Under the condition of uniform internal diameter, the sampling volume is linearly dependent on the liquid segment length, thereby greatly simplifying the volume calculation and sampling pressure control process, implementing visualization on the sampling volume, and enhancing the liquid intake precision. The capillary tips obtained by the method can be used for sampling animal / plant cell living bodies, and can be used as a mass spectroscopy sampling needle.

Description

technical field [0001] The invention relates to a method and a system for preparing tips with different shapes by etching micro-nano capillary tubes with equal inner diameters, belonging to the field of micro-machining. Background technique [0002] The miniaturization of analytical systems and the miniaturization of analytical samples are the development trends of analytical chemistry. Among them, how to realize the precise pipetting of nanoscale, picoliter or even femtoliter samples has become an urgent problem to be solved in modern analytical chemistry, especially in the field of micro-nanofluidic analysis and biological analysis. [0003] In view of the above problems, most of the existing solutions are: use a capillary with a tapered tip at one end as a pipette, and connect a micro-syringe or an electroosmotic pump at the other end as a pressure propulsion device, so as to realize the controllable transfer of a small volume of liquid. The existing mainstream method fo...

AI Technical Summary

Problems solved by technology

This method has realized mechanical automation. Although the preparation is fast and the shape of the tip is controllable, the fatal disadvantage of this method is that the inner and outer diameters of the obtained capillary tip are all tapered, and due to the limitation of the machine, the shape of the inner diameter of the cone is inevitable. Individual Differences

This makes it very difficult to accurately calculate the volume of liquid taken and to control the pressure when taking liquid.

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