CN-122016569-A - Micro rotor and method for detecting low surface tension of liquid based on rotation speed of micro rotor

CN122016569ACN 122016569 ACN122016569 ACN 122016569ACN-122016569-A

Abstract

The invention discloses a micro rotor and a method for detecting low surface tension of liquid based on the rotation speed of the micro rotor, belonging to the technical field of liquid surface tension testing devices, wherein the micro rotor comprises a rotation center, at least two radial arms in the same direction are processed on the rotation center, arc-shaped hydrophilic tanks communicated with the rotation center are processed on the radial arms, and the tail ends of the arc-shaped hydrophilic tanks are communicated with the outside; the width of the arc-shaped hydrophilic groove gradually decreases from the rotation center to the tail end of the radial arm. The method has the advantages that the low-surface-tension liquid is dripped into the rotation center of the micro rotor, the actual motion state of the micro rotor is analyzed by utilizing Tracker software, the test rotating speed result of the micro rotor is used for representing the tension of different low-surface-tension liquids, and the quick detection of the low-surface-tension liquid which is compatible with the water substrate is realized. The miniature rotor has good reusability, and the preparation method has strong applicability and can be widely applied to the fields of biomedicine, chemical industry, environmental detection and the like.

Inventors

YANG LONG
WANG YUAN
HE YI
WANG JUNLIN
DENG TINGTING
CAO JINGWEI
LIU YOUFU

Assignees

西南科技大学

Dates

Publication Date: 20260512
Application Date: 20260414

Claims (10)

1. A miniature rotor, comprising: The rotary center is provided with at least two radial arms in the same direction, the radial arms are provided with arc-shaped hydrophilic tanks communicated with the rotary center, and the tail ends of the arc-shaped hydrophilic tanks are communicated with the outside; The width of the arc-shaped hydrophilic groove gradually decreases from the rotation center to the tail end of the radial arm; the miniature rotor comprises a base layer, wherein an intermediate layer is attached to the upper surface of the base layer, and a surface layer is attached to the upper surface of the intermediate layer; the base layer and the surface layer have superhydrophobicity except for the arc-shaped hydrophilic groove, and the middle layer has hydrophilicity.
2. The miniature rotor of claim 1, wherein said base layer is polytetrafluoroethylene, said intermediate layer is polyimide, and said surface layer is polytetrafluoroethylene.
3. The micro-rotor according to any one of claims 1-2, wherein the method of manufacturing the micro-rotor comprises the steps of: Step one, attaching a polytetrafluoroethylene hydrophobic adhesive tape to the surface of polyimide, turning over, and attaching the polytetrafluoroethylene adhesive tape to the back of polyimide to form a three-layer structure of a base layer, a middle layer and a surface layer; step two, designing the appearance of the micro rotor through Auto CAD of two-dimensional drawing software; Step three, performing modification treatment on the surface layer by using femtosecond laser to ensure that the surface of the surface layer has super-hydrophobic performance; regulating and controlling laser parameters, and ablating to obtain an arc-shaped hydrophilic groove on the surface layer through the appearance of the designed miniature rotor, wherein the width of the arc-shaped hydrophilic groove is gradually reduced from the rotation center to the tail end of the radial arm; step five, cutting off the whole micro rotor from the three-layer structure by utilizing a laser processing technology; And step six, turning and focusing the micro rotor, and performing modification treatment by using femtosecond laser to ensure that the lower surface of the base layer has super-hydrophobic performance, so that the preparation of the micro rotor is completed.
4. The micro rotor according to claim 3, wherein in the third step, the surface layer is modified by using a femtosecond laser technology, three unidirectional scanning is performed by using the femtosecond laser, the processing parameters are that the scanning distance is 50 μm-60 μm, the femtosecond laser power is 50 μm-60 mW, and the scanning speed is 0.01 m/s-0.02 m/s.
5. A micro rotor according to claim 3, wherein in the fourth step, the specific method for obtaining the arc-shaped hydrophilic groove by ablation on the surface layer comprises the steps of performing line track ablation for 30 times by using a femtosecond laser, wherein the processing parameters are that the scanning interval is 50-60 μm, the femtosecond laser power is 200-210 mW, and the scanning speed is 0.01-0.02 m/s.
6. The micro rotor according to claim 3, wherein the specific method in the fifth step comprises the steps of cutting off the whole appearance of the micro rotor by using femtosecond laser, so that the micro rotor is separated from the three-layer structure, wherein the machining parameters are that the scanning times are 80-90 times, the femtosecond laser power is 300-310 mW, and the scanning speed is 0.01-0.02 m/s.
7. The micro rotor according to claim 3, wherein the specific method in the sixth step comprises the steps of overturning and fixing the cut micro rotor, precisely focusing the relative position of the micro rotor and laser processing in a region focusing mode, enabling a femtosecond laser scanning line to cover the bottom surface of the micro rotor, and performing three scanning lines, wherein the processing parameters are that the scanning distance is 50-60 mu m, the laser power is 50-60 mW, and the scanning line speed is 0.01-0.02 m/s.
8. A method for detecting low surface tension of a liquid based on the rotational speed of a micro-rotor, the micro-rotor being as claimed in any one of claims 1-2, comprising the steps of: S1, rotating and fixing the micro rotor on the water surface, respectively taking liquid with the same concentration and volume and different tensions, dripping the liquid at the rotation center of the micro rotor, enabling the liquid to flow outwards in an arc-shaped hydrophilic groove, and enabling the liquid to flow out from the tail end of the arc-shaped hydrophilic groove, wherein the surface tension of the liquid is smaller than that of the water, and generating a rotation moment on a radial arm of the micro rotor due to the Malagony effect so as to drive the micro rotor to rotate on the water surface; S2, analyzing the motion state of the micro rotor by using speed analysis software to obtain steady-state peak angular velocity omega max of the micro rotor, and obtaining the difference gamma between the steady-state peak angular velocity omega max of the micro rotor and the surface tension difference gamma of pure water and the surface tension of the liquid to be measured by the known surface tension of water and the surface tension of the liquid to be measured; S3, drawing points on the measurement result, obtaining a fitting curve of steady-state peak angular velocity omega max of the micro-rotor and the difference gamma between pure water and the surface tension of the liquid, and for the steady-state peak angular velocity of the unknown liquid at the steady-state moment, obtaining a corresponding liquid surface tension numerical range by utilizing a fitting curve of steady-state peak angular velocity omega max of the micro-rotor and the difference gamma between the pure water and the surface tension of the liquid to be measured, and further substituting the steady-state peak angular velocity of the unknown low-surface liquid into a omega max - & gtgamma fitting formula obtained by fitting, thereby obtaining the tension of the low-surface tension liquid.
9. The method for detecting low surface tension of liquid based on rotational speed of micro-rotor as recited in claim 8, wherein in S1, the volume concentration of liquid is 99%.
10. The method for detecting low surface tension of liquid based on micro-rotor speed as recited in claim 8, wherein in S2, said speed analysis software is Tracker physical tracking software.

Description

Micro rotor and method for detecting low surface tension of liquid based on rotation speed of micro rotor Technical Field The invention belongs to the technical field of liquid surface tension testing devices, and particularly relates to a micro rotor and a method for detecting low surface tension of liquid based on the rotation speed of the micro rotor. Background With the continuous development of the medical and chemical industries, the low-surface-tension liquid is widely applied to chemical reactions, municipal sewage treatment, biological medicine and environmental detection, and has important significance for the rapid detection of the low-surface-tension liquid. The traditional liquid surface tension detection method mainly comprises a hanging drop method, a hanging piece method, a rotary drop method and the like. Although the methods have higher precision under laboratory conditions, the problems of large equipment volume, complex operation, long time consumption, large sample demand, difficulty in realizing real-time or field detection and the like generally exist. The preparation of a portable and easy-to-operate micro-rotor is an effective solution to the problem of rapidly detecting the surface tension of a liquid. The existing method is generally expensive for the detection instrument of low surface tension liquid, is not easy to integrate and popularize, and limits the application of the detection instrument in portable detection and microfluidic systems. The comparison is as follows: the method and the device for measuring the surface tension of the liquid disclosed in the patent CN101142472A realize low-cost and anti-interference dynamic surface tension measurement by measuring the service life of bubbles, but are sensitive to the stability of gas flow; The liquid surface tension coefficient measuring instrument disclosed in the patent CN101887002A adopts an ultrathin metal sheet stretching frame and a communicating vessel type liquid level lifting mechanism, so that the measuring precision and stability are effectively improved, but the structure is relatively complex, the thin metal sheet is easy to deform, and the long-term durability is possibly influenced; The device for measuring the surface tension coefficient of the liquid disclosed in the patent CN109520893A has the advantages of relatively simple structure, low cost and visual operation, is suitable for teaching demonstration, but has large manual operation error, low precision and lack of environmental control, and is not suitable for testing in different scenes; The tension measuring hanging ring and the liquid surface tension measuring device disclosed in the patent CN116380724A are designed through the rigid hanging rod and the V-shaped contact edge, so that the measuring stability and the measuring precision are obviously improved, but the structure is complex, the cost is high, and the operation is relatively complicated. In order to further expand the current detection mode of the surface tension of the liquid, development of a miniature rotor driven by the liquid tension difference is needed, and the rotation speed of the rotor is used for representing the tension of the liquid to be detected. The rotor meets the core requirements that materials are selected to meet the requirements of hydrophilic and hydrophobic properties, the materials are further modified in a physical mode to avoid chemical hazards, the structural design is in an asymmetric mode, the diameter of the central liquid drop is required to meet the size of the single liquid volume, and good durability and repeatability can be maintained. Disclosure of Invention It is an object of the present invention to address at least the above problems and/or disadvantages and to provide at least the advantages described below. To achieve these objects and other advantages and in accordance with the purpose of the invention, there is provided a micro rotor including: The rotary center is provided with at least two radial arms in the same direction, the radial arms are provided with arc-shaped hydrophilic tanks communicated with the rotary center, and the tail ends of the arc-shaped hydrophilic tanks are communicated with the outside; The width of the arc-shaped hydrophilic groove gradually decreases from the rotation center to the tail end of the radial arm; the miniature rotor comprises a base layer, wherein an intermediate layer is attached to the upper surface of the base layer, and a surface layer is attached to the upper surface of the intermediate layer; the base layer and the surface layer have superhydrophobicity except for the arc-shaped hydrophilic groove, and the middle layer has hydrophilicity. Preferably, the base layer is made of polytetrafluoroethylene, the intermediate layer is made of polyimide, and the surface layer is made of polytetrafluoroethylene. Preferably, the preparation method of the micro rotor comprises the following steps: Step one, attachi