FIELD OF THE INVENTION

The invention belongs to the field of microfluidics, in particular to a microchannel actuator for light-controlled microfluidic movement.

DESCRIPTION OF RELATED ART

Precise manipulation of micro-liquid movement has broad industrial applications, such as in biomedical device, micro-liquid transport, microfluidic system, and the like. At present, light-controlled microfluidic movement, especially micro-liquid movement driven by light-induced capillary force, has attracted great research interest from researchers because the non-contact, instantaneity, fixed-point and precise control can be achieved by light control. Liquid movement driven by light depends on two forces: optical force and light-induced capillary force. When the micro-liquid movement is driven by light-induced capillary force, no special optical devices and complicated micro-assembly processes are needed, which greatly simplifies the movement control of the liquid.

Nevertheless, when driving the micro-liquid movement, the light-induced capillary force is subjected to the resistance from the three-phase contact line, which limits the micro-liquid movement to a large extent and seriously restricts its practical application. The light-induced capillary force can be generated by the light-induced wetting gradient or Marangoni effect. The capillary force generated by the light-induced wetting gradient is difficult to overcome the resistance of the three-phase contact line. Therefore, such driving method is only applicable to a specific liquid, and the liquid moves slowly and the movement track is limited to linear movement. The light-induced Marangoni effect often leads to an increase in the temperature of the driven liquid or a need to add a photosensitive surfactant, which is detrimental to the application in the biomedical field or leads to the contamination of the driven liquid.

Therefore, it is necessary to develop a micro-device for light-controlled microfluidic movement with a wide range of applications, easy operation and no pollution to liquid.

BRIEF SUMMARY OF THE INVENTION

An object of the present invention is to provide a microchannel actuator for light-controlled microfluidic movement.

Another object of the present invention is to provide an apparatus for light-controlled microfluidic movement.

Another object of the present invention is to provide a method for light-controlled microfluidic movement.

In the first aspect of the invention, a method for light-controlled microfluidic movement is provided, comprising the steps of:

providing a microchannel actuator (microtubule actuator), wherein the microchannel actuator has an outer diameter of 0.01-2 mm or 0.0012-2 mm and an inner diameter of 0.001-1.99 mm, and the wall material of the channel of the microchannel actuator is a polymer containing an azobenzene or an azo group;

loading a micro-fluid into the microchannel actuator;

illuminating one end of the micro-fluid-loaded microchannel actuator by a light source to drive the micro-fluid to move toward the other end of the microchannel actuator.

In the second aspect of the invention, a method for light-controlled microfluidic movement is provided, comprising the steps of:

providing a microchannel actuator, wherein microchannel actuator has an outer diameter of 0.01-2 mm or 0.0012-2 mm and an inner diameter of 0.001-1.99 mm, and the wall material of the channel of the microchannel actuator is a polymer containing an azobenzene or an azo group;

loading a micro-fluid into the microchannel actuator;

illuminating the micro-fluid-loaded microchannel actuator with light sources of different intensities to drive the micro-fluid to move from the end with high light intensity in the direction of low light intensity.

In another preferred embodiment, the whole or part of the wall material of the channel is a polymer material containing an azobenzene group or an azo group. The channel wall also contain one or more materials other than polymer material containing an azobenzene group or an azo group between the channel and above polymer.

In another preferred embodiment, the microchannel actuator comprises a substrate having a groove and a film, and the groove and the film together form a fluid channel; wherein the substrate and/or the film contain an effective amount of the wall material of the channel.

In another preferred embodiment, the effective amount refers to an amount sufficient to cause deformation of the substrate and/or the film under illumination by a light source.

In another preferred embodiment, the outer diameter of the microchannel actuator is the sum of the width (depth) of the groove and the thickness of the film of the wall material of the channel, and the inner diameter of the microchannel actuator is the width of the groove (depth).

In another preferred embodiment, the microchannel actuator further includes a composite layer wrapped around the inside and/or outside of the channel wall.

In another preferred embodiment, the wall material of the channel is prepared by homopolymerization or copolymerization of CAB monomers, wherein the chemical structure of the monomer CAB is:



wherein, R2is H, a C1, C2, C3, C4, C5, or C6 hydrocarbyl or alkoxy, or a terminal group with polarity selected from one of the group consisting of a cyano, an isocyano, a hydroxyl, a halogen, an ester group, a carboxyl, a nitro, an amino and an amide group;

R1is a C3, C4, C5, C6, C7, C8, C9, C10, C11, or C12 hydrocarbyl or alkoxy;

D is selected from one of the following structure formula (1)-structure formula (4):



wherein R3is a C2, C3, C4, C5, or C6 hydrocarbyl or alkoxy; or is not present in the monomer.

In another preferred embodiment, the wall material of the channel is prepared by copolymerizing a CAB monomer with a CF monomer, and the chemical structure formula of the monomer CF is selected from the group consisting of:



wherein, F represents: -D-R1-G-R2, D, R1and R2are the same as the group represented by the chemical formula in CAB, and the structure of G is selected from one or more of the following structures:



In another preferred embodiment, the wall material of the channel comprises structural units as follows:



wherein, R2is H, a C1, C2, C3, C4, C5, or C6 hydrocarbyl or alkoxy, or a terminal group with polarity selected from one of the group consisting of a cyano, an isocyano, a hydroxyl, a halogen, an ester group, a carboxyl, a nitro, an amino and an amide group;

R1is a C3, C4, C5, C6, C7, C8, C9, C10, C11, or C12 hydrocarbyl or alkoxy;

D is selected from one of the following structure formula (1)-structure formula (4):



wherein R3is a C2, C3, C4, C5 or C6 alkylene, alkenylene, alkynylene or an alkyleneoxy group.

In another preferred embodiment, the light sources of different intensities are produced by an attenuator.

In another preferred embodiment, the light sources of different intensities are produced by illuminating the micro-fluid.

In another preferred embodiment, the micro-fluid is a hydrophilic micro-fluid or a hydrophobic micro-fluid.

In another preferred embodiment, when the micro-fluid is a hydrophilic micro-fluid, the inner wall of the microchannel actuator is coated with a hydrophilic coating.

In another preferred embodiment, when the micro-fluid is a hydrophobic micro-fluid, the inner wall of the microchannel actuator is coated with or without a hydrophobic coating.

In another preferred embodiment, the micro-fluid is selected from the group consisting of an organic liquid, water, aqueous solution, gas-liquid fluid, liquid-solid fluid and emulsion.

In another preferred embodiment, the micro-fluid is an organic liquid, preferably an organic liquid selected from the group consisting of silicone oil, n-hexane, petroleum ether, ethyl acetate, acetone, methanol, ethanol, isopropanol, toluene, pentane, octane, cyclohexanone, diethyl ether, propylene oxide, methyl butanone, methyl isobutyl ketone, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, acetonitrile, pyridine, gasoline and a combination thereof.

In another preferred embodiment, the micro-fluid is an aqueous phase liquid, preferably an aqueous phase liquid selected from the group consisting of water and a salt solution.

In another preferred embodiment, the micro-fluid is a biochemical liquid, preferably a biochemical liquid selected from the group consisting of a protein solution, a phosphate buffer solution, a cell culture fluid, a cytosol and a combination thereof.

In another preferred embodiment, the micro-fluid is a complex fluid, preferably a complex fluid selected from the group consisting of a gas-liquid fluid, emulsion, liquid-solid fluid and a combination thereof.

In another preferred embodiment, the light source is ultraviolet light or visible light.

In another preferred embodiment, the illumination position of the light source is movable.

In another preferred embodiment, the method controls the direction of the microfluidic movement by controlling the direction of movement of the light or the direction of attenuation of the light.

In another preferred embodiment, the micro-fluid moves along the interior of the microchannel actuator as the light moves in a direction along the exterior of the microchannel actuator.

In another preferred embodiment, the micro-fluid is always moved from the end with a high light intensity in the direction in which the light intensity is low, regardless of the change in the direction of attenuation of the light.

In another preferred embodiment, the method adjusts the driving rate of the micro-fluid by controlling the intensity of the light source.

In another preferred embodiment, the light source has a light intensity of 0.01 to 10 W cm−2.

In another preferred embodiment, the micro-fluid has a rate of movement of 0-10 mm s−1.

In another preferred embodiment, when the light source illuminates the micro-fluid-loaded microchannel actuator, the inner and outer diameters of the channel being illuminated are enlarged to drive the micro-fluid to move toward the thinner end of the microchannel actuator.

In another preferred embodiment, the microchannel actuator is in a straight, serpentine or spiral form.

In another preferred embodiment, the method drives the microfluidic movement over a long distance.

In another preferred embodiment, the method drives a micro-fluid to climb.

In another preferred embodiment, the method drives the micro-fluid to climb at a slope of 0-60 degrees.

In another preferred embodiment, the method drives the micro-fluid to produce a helical three-dimensional movement track.

In the third aspect of the invention, a device for light-controlled microfluidic movement is provided, comprising a light source and a microchannel actuator; wherein the microchannel actuator has an outer diameter of 0.01-2 mm or 0.0012-2 mm, the inner diameter is 0.001 to 1.99 mm, and the wall material of the channel of the microchannel actuator is a polymer material containing an azobenzene or azo group.

In another preferred embodiment, when the micro-fluid is a hydrophilic micro-fluid, the inner wall of the microchannel actuator is coated with a hydrophilic coating.

In another preferred embodiment, when the micro-fluid is a hydrophobic micro-fluid, the inner wall of the microchannel actuator is coated with or without a hydrophobic coating.

In another preferred embodiment, the light source can be moved along the microchannel actuator; and/or an attenuator is placed between the light source and the microchannel actuator.

In another preferred embodiment, the attenuator is used to generate an attenuated light.

In the fourth aspect of the invention, a microchannel actuator for light-controlled microfluidic movement is provided, wherein the microchannel actuator has an outer diameter of 0.01-2 mm or 0.0012-2 mm and an inner diameter of 0.001-1.99 mm, and the wall material of the channel of the microchannel actuator is a polymer material containing an azobenzene or azo group.

In another preferred embodiment, when the micro-fluid is a hydrophilic micro-fluid, the inner wall of the microchannel actuator is coated with a hydrophilic coating.

In another preferred embodiment, when the micro-fluid is a hydrophobic micro-fluid, the inner wall of the microchannel actuator is coated with or without a hydrophobic coating.

In another preferred embodiment, the microchannel actuator is in a straight, serpentine or spiral form.

In another preferred embodiment, the microchannel actuator is circular, rectangular, square, other polygonal or irregular in cross section, preferably circular and square.

In another preferred embodiment, the microchannel actuator is prepared by a method (a) or (b) selected from the group consisting of:

(a) inhaling the azobenzene or azo group-containing polymer material solution into a glass capillary, and etching the glass capillary to obtain a microchannel actuator after the solvent is volatilized;

(b) providing a substrate having a groove and covering the substrate with a film to form a fluid channel thereby obtaining microchannel actuator, wherein one or both of the substrate and the film contain the wall material.

It is to be understood that within the scope of the present invention, each foregoing various technical features of the present invention and each technical feature specifically described hereinafter (eg, in the example) may be combined with each other to constitute a new or preferred technical solution. Due to space limitations, it will not be described one by one here.

