A glass-fiber probe-based method for measuring bubble driving force

Abstract

The application provides a kind of bubble driving force measurement method based on glass fiber probe, solid glass capillary and hollow glass capillary are drawn to predetermined tip size by capillary drawing instrument respectively, called glass fiber probe and hollow negative pressure tube;Use stepper motor to control hollow negative pressure tube to move to Janus particle side, and realize the capture of Janus particle in combination with negative pressure pump;Janus particle adsorbed by hollow glass capillary is close to glass fiber probe by two stepper motors, and Janus particle is adhered to glass fiber probe tip by ultraviolet glue;Glass fiber probe with Janus particle adhered is placed in a certain concentration of hydrogen peroxide under the clamping of stepper motor, and side shooting is carried out by high-speed camera.The application can obtain the change rule of Janus particle driving force under different liquid depth, and also can obtain the growth and evolution rule of bubble with the depth from liquid surface.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of microfluidics, and particularly relates to a bubble driving force measurement method based on a glass fiber probe. BACKGROUND

[0002] A typical Janus spherical micromotor has one hemisphere made of platinum (Pt) and the other hemisphere made of SiO2. It has been found in research that, in an H2O2 solution, oxygen molecules can condense and form bubbles due to a catalytic decomposition reaction on the Pt surface, and the bubbles provide driving force. Due to the high energy of bubble collapse, the bubble-driven micromotor has strong movement ability, which makes it have strong application prospects in the fields of efficient water pollution treatment and medical health. The movement ability of the Janus particle and its application are closely related to the bubble dynamics of the Janus particle. However, due to the complex movement law of the Janus particle, and the high requirements for the camera angle, light source position and liquid surface flatness in lateral shooting due to the micron scale of the Janus particle, there are few related researches. SUMMARY

[0003] To solve the above technical problems, the application provides a bubble driving force measurement method based on a glass fiber probe, so as to obtain the change law of the driving force of the Janus particle under different liquid depths, and also obtain the growth and evolution law of the bubble with the liquid depth.

[0004] To achieve the above purpose, the technical scheme adopted by the application is as follows:

[0005] A bubble driving force measurement method based on a glass fiber probe, comprising the following steps:

[0006] Step 1, a solid glass capillary and a hollow glass capillary are drawn to a predetermined tip size by a capillary wire drawing instrument to form a glass fiber probe and a hollow negative pressure tube;

[0007] Step 2, a step motor is used to control the movement of the hollow negative pressure tube to one side of the Janus particle, and a negative pressure pump is used to realize the grabbing of the Janus particle;

[0008] Step 3, the Janus particle adsorbed by the hollow glass capillary is brought close to the glass fiber probe by two step motors, and the Janus particle is adhered to the tip of the glass fiber probe by ultraviolet glue;

[0009] Step 4, the glass fiber probe with the adhered Janus particle is placed in a certain concentration of hydrogen peroxide under the clamping of the step motor, and a high-speed camera is used to take a lateral picture, and the displacement information of the Janus particle is recorded;

[0010] Step 5, using the displacement information in step 4, the speed-time relationship of the Janus particle is obtained by first-order derivation on time, and the acceleration-time relationship of the Janus particle is obtained by derivation, and the driving force of the bubble on the Janus particle is obtained through the Langevin equation: Wherein x, The displacement, velocity and acceleration of the Janus particle are respectively, k is the elastic coefficient of the tip of the glass fiber probe, ξ is the damping coefficient of the Janus particle and hydrogen peroxide, and m is the mass of the Janus particle.

[0011] Further, the step 3 comprises: using a stepping motor to control the hollow negative pressure pipe to adhere the Janus particle to the tip of the glass fiber probe through ultraviolet glue, and heating through a heating device at a distance from the Janus particle to make it bend 90 degrees.

[0012] Further, the step 4 comprises: controlling the distance of the Janus particle from the liquid surface in hydrogen peroxide through a stepping motor.

[0013] Further, in step 4, an light source is arranged on the opposite side of the high-speed camera during shooting.

[0014] Further, the elastic coefficient of the glass fiber probe is calibrated by the method of adding liquid drops of different masses, that is, by adding liquid drops of different masses, the deformation of the glass fiber probe is recorded by a high-speed camera, and a force-deformation curve is drawn to calculate the slope as the elastic coefficient.

[0015] Beneficial effects:

[0016] The glass fiber probe is bonded with the Janus particle, the distance of the Janus particle from the liquid surface can be changed by using a stepping motor, and real-time observation can be carried out through a high-speed camera, so that the change rule of the driving force of the Janus particle under different liquid depths can be obtained, and the growth and evolution rule of the bubble with the depth from the liquid surface can also be obtained. DETAILED DESCRIPTION

[0017] Figure 1 is a schematic diagram for grabbing the Janus particle;

[0018] Figure 2 is a schematic diagram for adhering the Janus particle in the production of the glass fiber probe;

[0019] Figure 3a is a schematic diagram for heating and bending in the production of the fiber probe Figure 1 ;

[0020] Figure 3b is a schematic diagram for heating and bending in the production of the fiber probe Figure 2 ;

[0021] Figure 4 A schematic diagram for measuring the glass fiber probe technology experiment;

[0022] Figure 5 A schematic diagram for shooting angle;

[0023] Figure 6 A physical diagram of the glass fiber probe;

[0024] Figure 7 A glass fiber probe technology experiment photograph.

[0025] Wherein: Janus particle 1, ultraviolet glue 2, glass fiber probe 3, heating device 4, hydrogen peroxide 5, stepping motor 6, high-speed camera 7, ultraviolet light 8, hollow negative pressure pipe 9, negative pressure pump 10, glass sheet 11, light source 12, bubble 13. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical scheme and advantages of the present application more clear, the present application is further described in detail below in combination with the drawings and examples. It should be understood that the specific examples described herein are only used to explain the present application and not to limit the present application. In addition, the technical features involved in each embodiment of the present application described below can be combined with each other as long as they do not conflict with each other.

[0027] The glass fiber probe-based bubble driving force measurement method of the present application specifically includes the following steps:

[0028] Step 1, by means of a capillary wire drawing instrument, a solid glass capillary and a hollow glass capillary are drawn to a predetermined tip size to form a glass fiber probe and a hollow negative pressure pipe;

[0029] Step 2, Janus particles 1 are placed on a glass sheet 11, a stepping motor 6 is used to control the movement of the hollow negative pressure pipe 9 to the side of the Janus particles 1, and a negative pressure pump 10 is used to provide negative pressure to achieve adsorption and grabbing of the Janus particles 1;

[0030] Step 3, the Janus particles 1 adsorbed by the hollow negative pressure pipe 9 are moved closer to the glass fiber probe 3 by two stepping motors 6, and the Janus particles 1 are adhered by curing the ultraviolet glue 2 at the tip of the glass fiber probe by ultraviolet light 8;

[0031] Step 4, the glass fiber probe with the adhered Janus particles 1 is placed in a certain concentration of hydrogen peroxide 5 under the clamping of the stepping motor 6, the Janus particles 1 generate bubbles 13, the bubbles 13 push the Janus particles 1 and cause deformation of the tip of the glass fiber probe 3, side shooting is performed by a high-speed camera 7, and displacement information of the Janus particles 1 is recorded, and a light source 12 is arranged on the opposite side of the high-speed camera 7 during shooting.

[0032] Step 5, using the recorded displacement information above, the velocity-time relationship of Janus particle 1 is obtained by first-order derivative of time, and the acceleration-time relationship of Janus particle 1 is obtained by derivative, and the driving force of the bubble on the particle can be obtained by the equation of motion: Where x, is the displacement, velocity and acceleration of Janus particle 1 respectively, k is the elastic coefficient of the glass fiber probe 3 tip, ξ is the damping coefficient of Janus particle 1 and hydrogen peroxide 5, and m is the mass of Janus particle 1.

[0033] Specifically, first, the solid glass capillary and the hollow glass capillary are respectively drawn to the predetermined tip size by the capillary drawing instrument to make the glass fiber probe 3 with the predetermined elastic coefficient k and the hollow negative pressure pipe 9 with the predetermined tip size.

[0034] As shown in Figure 1 , the Janus particle 1 is placed on the glass sheet 11, the step motor 6 is used to control the hollow negative pressure pipe 9 to move to the side of the Janus particle 1, and the negative pressure pump 10 is used to provide negative pressure to realize the adsorption and grabbing of the Janus particle 1.

[0035] As shown in Figure 2 , the step motor 6 is used to control the hollow negative pressure pipe 9 to adhere the Janus particle 1 to the tip of the glass fiber probe 3 through the ultraviolet glue 2, as shown in Figure 6 , and heat it at a distance from the Janus particle 1 to make it bend 90 degrees, as shown in Figure 3a , Figure 3b , by the heating device 4. At this time, the glass fiber probe 3 and the Janus particle 1 are assembled.

[0036] As shown in Figure 4 , when measuring, the front end of the glass fiber probe 3 needs to be immersed in a certain concentration of hydrogen peroxide 5 to make the Janus particle 1 catalyze the generation of bubbles 13, and through the step motor 6, the distance of the Janus particle 1 from the liquid surface in the hydrogen peroxide 5 can be controlled to observe the displacement information of the Janus particle 1 at different heights from the liquid surface and the growth evolution law of the bubbles 13.

[0037] The above information is recorded by a high-speed camera 7, Figure 5 , the position shown in Figure 4 is the vertical direction of the angle of view, that is, the position shown by the dotted line is Figure 4 , the angle of view, when shooting, a light source 12 needs to be arranged on the opposite side of the high-speed camera 7, Figure 7 , as shown in Figure 4The real photo of the view angle. The position-time information of the Janus particle 1 can be recorded by the high-speed camera 7, and the velocity-time relationship of the Janus particle 1 can be obtained by taking the first-order derivative of the time with the displacement information, and the acceleration-time relationship of the Janus particle 1 can be obtained by taking the derivative of the velocity-time relationship, and it can be known from the Langevin equation that the driving force of the bubble on the particle is composed of three parts, which are elastic force, viscous force and inertial force, wherein the elastic force F 弹 =kx, the viscous force: and the inertial force The resultant force is: Wherein x, is the displacement, velocity and acceleration of the Janus particle 1 respectively, k is the elastic coefficient of the tip of the glass fiber probe 3, ξ is the damping coefficient of the Janus particle 1 and the hydrogen peroxide 5, and m is the mass of the Janus particle 1.

[0038] The method can also obtain different elastic coefficients k by making glass fiber probes 3 of different thicknesses to be suitable for measuring the driving force of different objects.

[0039] Those skilled in the art can easily understand that the above description is only a preferred embodiment of the present application, and is not used to limit the present application, and any modification, equivalent replacement and improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method for measuring bubble driving force based on a glass fiber probe, characterized in that, Includes the following steps: Step 1: Using a capillary drawing machine, solid glass capillaries and hollow glass capillaries are drawn to the predetermined tip size to form glass fiber probes and hollow negative pressure tubes. Step 2: Use a stepper motor to control the hollow negative pressure tube to move to the side of the Janus particles, and combine it with a negative pressure pump to grasp the Janus particles. Step 3: Using two stepper motors, bring the Janus particles adsorbed by the hollow glass capillary close to the glass fiber probe, and use UV adhesive to make the Janus particles adhere to the tip of the glass fiber probe. Step 4: Place the glass fiber probe with Janus particles attached into a certain concentration of hydrogen peroxide under the clamp of a stepper motor, and take a side view using a high-speed camera to record the displacement information of the Janus particles. Step 5: Using the displacement information from Step 4, determine the velocity-time relationship of the Janus particle by taking the first derivative with respect to time, then differentiate it to obtain the acceleration-time relationship of the Janus particle. Finally, use the Langevin equation to determine the driving force of the bubble on the Janus particle. Where x, ξ represents the displacement, velocity, and acceleration of the Janus particle, respectively; k is the elastic coefficient of the tip of the glass fiber probe; ξ is the damping coefficient of the Janus particle and hydrogen peroxide; and m is the mass of the Janus particle.

2. The method for measuring bubble driving force based on a glass fiber probe according to claim 1, characterized in that, Step 3 includes: using a stepper motor to control a hollow negative pressure tube to adhere Janus particles to the tip of a glass fiber probe with UV adhesive, and heating the Janus particles at a certain distance from the probe with a heating device to bend them by 90 degrees.

3. The method for measuring bubble driving force based on a glass fiber probe according to claim 2, characterized in that, Step 4 includes: controlling the distance between Janus particles and the liquid surface in hydrogen peroxide using a stepper motor.

4. The method for measuring bubble driving force based on a glass fiber probe according to claim 3, characterized in that, In step 4, a light source is placed on the opposite side of the high-speed camera during shooting.

5. The method for measuring bubble driving force based on a glass fiber probe according to claim 1, characterized in that, The elastic coefficient of a glass fiber probe is calibrated by adding droplets of different masses. Specifically, by adding droplets of different masses, the deformation of the glass fiber probe is recorded by a high-speed camera, a force-deformation curve is plotted, and the slope is calculated as the elastic coefficient.

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