CN216284808U

CN216284808U - Upward-warping blunt needle capable of preventing streaming, achieving low adhesion and dispensing liquid drops without residues

Info

Publication number: CN216284808U
Application number: CN202121669817.XU
Authority: CN
Inventors: 董智超; 周珊; 江雷
Original assignee: Beijing Bionic Interface Science And Technology Research Institute; Beijing Chaorun Bionic Interface Technology Co ltd
Current assignee: Beijing Yunchao Bionic Intelligence Technology Development Co ltd
Priority date: 2021-07-22
Filing date: 2021-07-22
Publication date: 2022-04-12
Anticipated expiration: 2031-07-22

Abstract

The utility model provides an upward-warping blunt needle head with the advantages of flow bypassing prevention, low adhesion and no residue for liquid drop distribution, which comprises a needle stem and a needle point, wherein the front end of the needle stem is an inclined plane, and the needle point sequentially comprises: the upturned needle head, the blunt tip and the concave-convex curvature reversing structure; upwarp syringe needle incurve perk and lower part opening, and the unsmooth camber reversal structure front end is outside bellied enclosed construction, and the upwarp syringe needle is used for making the liquid that flows out from the needle stalk along crooked side landing, and blunt point is used for avoiding the liquid adhesion on the needle point, and unsmooth camber reversal structure is used for making the liquid column fracture one-tenth liquid drop. The utility model aims to solve the problem of adhesion residue in liquid drop distribution, and the extruded liquid drops move downwards along the curved side of the needle head, so that the liquid drops can be prevented from overflowing the outer wall of the needle head and then climbing upwards along the outer wall of the needle head, and the extrusion distribution of low surface tension and viscous liquid without circumfluence is realized.

Description

Upward-warping blunt needle capable of preventing streaming, achieving low adhesion and dispensing liquid drops without residues

Technical Field

The utility model relates to the technical field of measurement and testing, in particular to an upwarping blunt needle head capable of preventing circumfluence, realizing low adhesion and dispensing liquid drops without residues.

Background

In the conventional contact angle measurement process, a needle is required to dispense liquid drops to a substrate for imaging, a common flat needle is greatly adhered to the liquid drops, and a large amount of liquid drops are left after leaving the needle, so that the dispensed liquid amount is inaccurate. In addition, for a super-hydrophobic substrate, due to its extremely low adhesion, a droplet is difficult to drop to its surface, and in order to allow the droplet to drop, repeated squeezing and rubbing of the droplet are required, which may cause the substrate to be pierced, the droplet pinning to occur, or the droplet to be triboelectrically charged, eventually resulting in a great contact angle measurement error. Existing methods cause drops to break off naturally, for example by increasing the volume of the drop dispensed, but gravity has an effect on the contact angle value. Small droplets can also be produced by spraying, but external energy is introduced and the operation is complicated. In addition, when the solid substrate is subjected to super-full-sparse representation, a common needle is required to extrude liquids such as ethanol with low surface tension, various organic oils and high-viscosity silicone oil, the liquids can generate circumfluence at the needle and then climb along the outer wall of the needle, so that the residual distributed liquid and the inaccurate distributed liquid amount can be caused, and further, the contact angle measurement error is caused. Therefore, it is necessary to develop a droplet dispensing apparatus capable of dispensing droplets with low adhesion and without leaving residues and suppressing the bypass of various liquids.

Disclosure of Invention

The utility model aims to solve the problem of adhesion residue in liquid drop distribution, the common sharp needle is bent upwards, and the bent sharp needle is passivated to obtain an upturned bent blunt needle, and the extruded liquid drops move downwards along the bent side of the needle, so that the liquid drops can be prevented from overflowing the outer wall of the needle and then climbing upwards along the outer wall of the needle, the extrusion distribution of low surface tension and viscous liquid without circumfluence is realized, and the problem that the liquid drops are difficult to accurately distribute in the process of the ultra-full-sparse characterization of a solid substrate is solved. In addition, because the contact area between the blunt sharp structure of protruding and the liquid drop is minimum, therefore the adhesion between liquid-solid is extremely low, a small amount of liquid drop need not to contact the basement just can drop naturally under the action of gravity to can avoid the deformation of liquid drop in extrusion and the tensile process, solve the problem that the liquid drop is difficult to the desorption in super hydrophobic basement contact angle measurement process, and because the adhesion between liquid-solid is extremely low, the liquid drop does not have the residue after dropping from this syringe needle, the liquid measure of distribution is accurate, this measuring error that can greatly reduced contact angle. The blunt curved needle is simple to prepare, low in cost and capable of greatly optimizing the measurement of the contact angle.

The utility model provides an upward-warping blunt needle head with the advantages of flow bypassing prevention, low adhesion, no residue and liquid drop distribution, which comprises a hollow tubular needle stem and a needle point arranged at the front end of the needle stem, wherein the hollow tubular needle stem and the needle point are sequentially arranged;

the needle point includes in proper order: an upwarp needle head which is connected with the front end of the needle stem and is upwarp, a blunt tip and a concave-convex curvature inversion structure;

the upwarp needle head is bent upwards and upwarps, the lower part of the upwarp needle head is opened, the upwarp needle head comprises an upwarp first boundary and an upwarp second boundary, the blunt tip is connected with the front ends of the upwarp first boundary and the upwarp second boundary, the blunt tip comprises a blunt tip first boundary and a blunt tip second boundary, the included angle between the blunt tip first boundary and the upwarp first boundary is an obtuse angle, the included angle between the blunt tip second boundary and the upwarp second boundary is an obtuse angle, and the front end of the blunt tip first boundary is intersected with the front end of the blunt tip second boundary;

the front end of the concave-convex curvature reversal structure is an outward convex closed structure;

the upwarping needle head is used for enabling liquid flowing out of the needle stem to slide along the bent side, the blunt tip is used for avoiding the liquid from being adhered to the needle tip, and the concave-convex curvature reversing structure is used for enabling the liquid column to be broken into liquid drops.

The upwarping blunt needle head with the advantages of anti-streaming, low adhesion and no residue for dispensing liquid drops has an angle of pi/4 as a preferred mode.

The upwarping blunt needle capable of preventing circumfluence, realizing low adhesion and no residue and dispensing liquid drops is preferably used for measuring a contact angle.

The specific implementation scheme is as follows: the head of a common sharp needle is bent upwards to obtain an upturned bent needle head, then the needle point is rubbed to be passivated to obtain a blunt point, a concave-convex curvature inversion structure is formed at the joint position of a concave curvature structure of an originally concave circular groove of the needle head and a convex curvature structure of the blunt needle point, extruded liquid slides down along the bent side of the blunt needle head, and then the blunt needle head is broken at the concave-convex curvature inversion position.

The utility model has the following advantages:

the prior art, for example, realizes low-adhesion residue-free distribution of small droplets by hydrophobizing a treatment needle, has complex preparation process and high cost, and cannot accurately control the volume of the obtained droplets. Other techniques, such as dispensing small droplets by spraying, introduce external energy and are complex and costly to operate. The scheme bends a common sharp needle and then partially passivates the needle point position, extruded liquid drops move downwards along the bent side of the needle head, so that the liquid drops can be prevented from flowing around the outer wall of the needle head, in addition, a curvature reversal structure is formed at the joint position of a concave curvature structure of a circular groove in the needle head and a convex curvature structure of the blunt needle point, the structure promotes liquid to be broken into liquid drops, the liquid-solid contact surface area of the obtained convex blunt needle point is small, the adhesion to the liquid drops is extremely low, the liquid drops can be distributed without flowing around and residual under the synergistic action of promoting the liquid breaking by the concave-convex curvature reversal structure and the low adhesion of the convex curvature structure to the liquid drops, and the method is simple, low in cost and very suitable for actual production and life.

Drawings

FIG. 1 is a perspective view of an upturned blunt needle tip for dispensing droplets with anti-bypass and low adhesion and no residue;

FIG. 2 is a side view of a blunted, upturned needle tip for dispensing droplets with anti-bypass flow and low adhesion and no residue;

FIG. 3 is a front view of a blunted, upturned needle tip for dispensing droplets with anti-bypass and low adhesion and no residue;

FIG. 4 is a bottom view of a blunted, upwardly-bent needle tip that is impervious to bypass flow and low-stick residue-free to dispense droplets.

Reference numerals:

1. needle peduncle; 2. a needle tip; 21. raising the needle head; 211. warping the first boundary; 212. warping up the second boundary; 22. a blunt tip; 221. a blunt tip first boundary; 222. a blunt tip second boundary; 23. concave-convex curvature reversal structure.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments.

Example 1

As shown in fig. 1-4, an upwarping blunt needle head with anti-bypass flow, low adhesion and no residue for distributing liquid drops comprises a hollow tubular needle stem 1 and a needle point 2 arranged at the front end of the needle stem 1, which are arranged in sequence, wherein the front end of the needle stem 1 is an inclined plane;

the needle tip 2 comprises in sequence: an upwarp needle head 21 which is connected with the front end of the needle stem 1 and is upwarp, a blunt tip 22 and a concave-convex curvature reversal structure 23;

the upwarp needle 21 is bent and upwarped upwards and has an opening at the lower part, the upwarp needle 21 comprises an upwarp first boundary 211 and an upwarp second boundary 212, the blunt tip 22 is connected with the front ends of the upwarp first boundary 211 and the upwarp second boundary 212, the blunt tip 22 comprises a blunt tip first boundary 221 and a blunt tip second boundary 222, the included angle between the blunt tip first boundary 221 and the upwarp first boundary 211 is an obtuse angle, the included angle between the blunt tip second boundary 222 and the upwarp second boundary 212 is an obtuse angle, and the front end of the blunt tip first boundary 221 is intersected with the front end of the blunt tip second boundary 222;

the front end of the concave-convex curvature reversal structure 3 is an outward convex closed structure;

the upturned needle head 21 is used for enabling liquid flowing out of the needle stem 1 to slide along the curved side, the blunt tip 22 is used for preventing the liquid from being adhered to the needle tip 2, and the concave-convex curvature reversing structure 23 is used for enabling the liquid column to be broken into liquid drops.

Example 2

the upturned needle head 21 is used for enabling liquid flowing out of the needle stem 1 to slide along the curved side, the blunt tip 22 is used for preventing the liquid from being adhered to the needle tip 2, and the concave-convex curvature reversing structure 23 is used for enabling the liquid column to be broken into liquid drops;

the angle of the upwarping needle head 21 is pi/4;

a blunt needle tip that is upturned is used for contact angle measurement.

The specific application method of the embodiment 1 and the embodiment 2 is as follows: the extruded liquid comes to the needle point 2 through the needle stem 1, slides down along the curved side of the upturned needle head 21, then is broken at the concave-convex curvature inversion position of the concave-convex curvature inversion structure 23, due to the extremely small liquid-solid contact area at the blunt tip 22, the liquid-solid adhesion is extremely low, liquid drops can naturally fall off from the blunt tip 22 to a substrate to be measured, no residue exists, and then imaging and contact angle measurement can be carried out.

The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art should be considered to be within the technical scope of the present invention, and equivalent alternatives or modifications according to the technical solution of the present invention and the inventive concept thereof should be covered by the scope of the present invention.

Claims

1. An anti-bypass, low-stick, residue-free, upturned blunt needle for dispensing droplets, comprising: the needle comprises a hollow tubular needle stem (1) and a needle point (2) arranged at the front end of the needle stem (1), wherein the hollow tubular needle stem (1) and the needle point are arranged in sequence, and the front end of the needle stem (1) is an inclined plane;

the needle point (2) comprises in sequence: an upwarp needle head (21) which is connected with the front end of the needle stem (1) and is upwarp, a blunt tip (22) and a concave-convex curvature reversal structure (23);

the upwarping needle head (21) is bent upwards and upwarps, the lower portion of the upwarping needle head (21) is provided with an opening, the upwarping needle head (21) comprises an upwarping first boundary (211) and an upwarping second boundary (212), the blunt tip (22) is connected with the front ends of the upwarping first boundary (211) and the upwarping second boundary (212), the blunt tip (22) comprises a blunt tip first boundary (221) and a blunt tip second boundary (222), an included angle between the blunt tip first boundary (221) and the upwarping first boundary (211) is an obtuse angle, an included angle between the blunt tip second boundary (222) and the upwarping second boundary (212) is an obtuse angle, and the front end of the blunt tip first boundary (221) is intersected with the front end of the blunt tip second boundary (222);

the front end of the concave-convex curvature reversal structure (23) is an outward convex closed structure;

upwarping syringe needle (21) are used for making the follow the liquid that needle stalk (1) flowed out slides along crooked side, blunt point (22) are used for avoiding liquid adhesion is in on needle point (2), unsmooth camber reversal structure (23) are used for making the liquid column fracture become the liquid droplet.

2. The upwarp blunt needle of claim 1 for dispensing droplets with anti-bypass and low adhesion and no residue, wherein: the angle of the upwarping needle head (21) is pi/4.

3. The upwarp blunt needle of claim 1 for dispensing droplets with anti-bypass and low adhesion and no residue, wherein: the upturned blunt needle is used for contact angle measurement.