阅读说明：本技术 微米级磁性镊子的制备与使用方法 (Preparation and use method of micron-sized magnetic tweezers ) 是由 王正直 王琨 倪克 于 2020-04-24 设计创作，主要内容包括：本发明公开了一种微米级磁性镊子的制备与使用方法。包括以下步骤：1)将颗粒填充(非磁性物质包裹的磁性粒子)纳米复合树脂滴到模板基底上,树脂渗透到模板基底的空腔内以形成产物Ⅰ；2)施加磁场,树脂内磁性粒子重新分配形成产物Ⅱ；3)用光将未被光掩模版遮挡的树脂固化,形成产物Ⅲ,得到固化的微柱Ⅰ；4)交换磁极,磁性粒子再分配,再固化,形成产物Ⅳ,得到固化的微柱Ⅱ；5)将产物Ⅳ从模板基底上剥离,就得到混合分布的微柱Ⅲ；6)对微柱Ⅲ施加平行的磁场,以达到微型镊子的效果。本发明所制得的微型镊子可以夹起微米级的颗粒,通过施加及移除磁场使得微型镊子可以重复使用,另外树脂经过磁性粒子的填充,其硬度,刚度也大大提高。(The invention discloses a preparation and use method of micron-sized magnetic tweezers. The method comprises the following steps: 1) dripping particle filling (magnetic particles wrapped by nonmagnetic substances) nano composite resin on a template substrate, and infiltrating the resin into a cavity of the template substrate to form a product I; 2) applying a magnetic field to redistribute the magnetic particles in the resin to form a product II; 3) curing the resin which is not shielded by the photomask plate by light to form a product III to obtain a cured microcolumn I; 4) exchanging magnetic poles, redistributing the magnetic particles, and curing to form a product IV to obtain a cured microcolumn II; 5) stripping the product IV from the template substrate to obtain a microcolumn III in mixed distribution; 6) and applying a parallel magnetic field to the microcolumn III to achieve the effect of the micro-tweezers. The micro tweezers prepared by the invention can clamp micron-sized particles, the micro tweezers can be repeatedly used by applying and removing a magnetic field, and in addition, the hardness and the rigidity of the resin are greatly improved by filling the resin with magnetic particles.)

1. A preparation and use method of micron-sized magnetic tweezers is characterized in that: the method comprises the following steps:

1) dripping the nano composite resin filled with the non-magnetic substance wrapped magnetic particles on a template substrate, and infiltrating the nano composite resin into a column cavity of the template substrate through a vacuum auxiliary forming process to form a product I;

2) respectively placing two parallel magnets vertically above and below the product I to enable the product I to be subjected to a magnetic field in the vertical direction, so that magnetic particles are redistributed in the product I to form a product II;

3) shielding one template substrate column cavity by using a photomask, irradiating by using blue light, and carrying out photocuring reaction on the unshielded template substrate column cavity to form a product III to obtain a cured microcolumn I;

4) exchanging the two parallel magnet poles in the step 2), changing the product III by a magnetic field to generate opposite movement for the magnetic particles in the column cavity of the solidified microcolumn I, taking away the photomask after the magnetic particles are redistributed, and solidifying the uncured template substrate column cavity by light to form a product IV to obtain a solidified microcolumn II;

5) stripping the product IV from the template substrate to obtain two solidified mixed micro-columns;

6) and applying parallel magnetic fields to the two mixed microcolumns, wherein the two mixed microcolumns generate different deformations due to different material parameters and stress modes so as to achieve the effect of the micro-tweezers.

2. The method of making and using the micrometer-sized magnetic tweezers of claim 1, wherein: the mass fraction of the magnetic particles in the nano composite resin in the step 1) is 10-30%.

3. The method of manufacturing and using the micro-scale magnetic tweezers of claim 1 or 2, wherein: the nonmagnetic substance in the step 1) is SiO₂、SiC、Si₃N₄、TiN、TiO₂Any one or more of TiC or BN is mixed to reduce agglomeration between magnetic particles.

4. The method of manufacturing and using the micro-scale magnetic tweezers of claim 1 or 2, wherein: the nano composite resin material in the step 1) is photo-curable high-elasticity polymer resin.

5. The method of making and using the micrometer scale magnetic tweezers of claim 3, wherein: the nano composite resin material in the step 1) is photo-curable high-elasticity polymer resin.

6. The method for preparing and using the micron-sized magnetic tweezers of claim 5, wherein the method comprises the following steps: the high-elasticity polymer resin is photosensitive polyurethane.

7. The method of making and using the micrometer-scale magnetic tweezers of claim 1, 2, 5, or 6, wherein: the magnetic particles in the step 1) are Fe and Fe₂O₃、Fe₃O₄Any one or more of Co and Ni.

8. The method of making and using the micrometer-scale magnetic tweezers of claim 1, 2, 5, or 6, wherein: the template substrate in the step 1) adopts a silicon template with a regular cavity.

Technical Field

The invention relates to the technical field of functional composite material preparation, in particular to a preparation and use method of micron-sized magnetic tweezers.

Background

Tweezers are an instrument that is used for pressing from both sides the taking of cubic medicine, metal particle, hair, spiny and other tiny east west, but along with being pressed from both sides the reduction of getting thing diameter volume, the degree of difficulty greatly increased that macroscopic tweezers accomplished the operation needs miniature tweezers to take micro-nano horizontally article.

Micromanipulation techniques have not only been of great importance in microelectromechanical assembly, but also have been increasingly appreciated in many other areas today, such as medical care and health, where the most studied are tweezers micromanipulators. However, in view of the actual needs at the present stage, the more important is the research on the micromanipulator capable of operating the micrometer-scale object, so that the micro-tweezers made of single-arm carbon fiber is thought to be capable of clamping micrometer-scale substances, but the micro-tweezers are all troublesome to manufacture and require a precise instrument to operate.

Disclosure of Invention

Aiming at the defects of the prior art, the invention aims to provide a preparation and use method of micron-sized magnetic tweezers.

In order to achieve the purpose, the invention provides a preparation and use method of micron-sized magnetic tweezers, which is characterized in that: the method comprises the following steps:

1) dripping the nano composite resin filled with the non-magnetic substance wrapped magnetic particles on a template substrate, and infiltrating the nano composite resin into a column cavity of the template substrate through a vacuum auxiliary forming process to form a product I;

2) respectively placing two parallel magnets vertically above and below the product I to enable the product I to be subjected to a magnetic field in the vertical direction, so that magnetic particles are redistributed in the product I to form a product II;

3) shielding one template substrate column cavity by using a photomask, irradiating by using blue light, and carrying out photocuring reaction on the unshielded template substrate column cavity to form a product III to obtain a cured microcolumn I;

4) exchanging the two parallel magnet poles in the step 2), changing the product III by a magnetic field to generate opposite movement for the magnetic particles in the column cavity of the solidified microcolumn I, taking away the photomask after the magnetic particles are redistributed, and solidifying the uncured template substrate column cavity by light to form a product IV to obtain a solidified microcolumn II;

5) stripping the product IV from the template substrate to obtain two solidified mixed micro-columns;

6) and applying parallel magnetic fields to the two mixed microcolumns, wherein the two mixed microcolumns generate different deformations due to different material parameters and stress modes so as to achieve the effect of the micro-tweezers.

Preferably, the mass fraction of the magnetic particles in the nanocomposite resin in the step 1) is 10 to 30%.

Further, the nonmagnetic substance in the step 1) is SiO₂、SiC、Si₃N₄、TiN、TiO₂Any one or more of TiC or BN is mixed to reduce agglomeration between magnetic particles.

Further, the nanocomposite resin material in the step 1) is a photocurable highly elastic polymer resin.

Further, the highly elastic polymer resin is a photosensitive polyurethane.

Further, the magnetic particles in the step 1) are Fe and Fe₂O₃、Fe₃O₄Any one or more of Co and Ni.

Further, the template substrate in step 1) adopts a silicon template with regular cavities.

The invention has the following beneficial effects and advantages:

the invention realizes the gradient distribution and redistribution of magnetic particles by using a magnetic field, and can realize the preparation of micro-tweezers with the grade below 10 microns; meanwhile, the addition of the particles greatly improves the strength and rigidity of the microcolumn; the deformation of the microcolumn is changed by applying a magnetic field, so that the clamping action is realized, the magnetic field is removed, the microcolumn recovers to deform, the clamped articles fall off, and the function of placing and taking is completed.

The micro-tweezers prepared by the invention has simple manufacturing method, can obtain a finished product only by twice curing, has a much simpler mode compared with other micro-tweezers, and can change the acting force of the micro-tweezers during clamping by changing the size of the parallel magnetic field to prevent the samples from being damaged by clamping.

Drawings

FIG. 1 is a flow chart of the preparation and application method of the magnetic tweezers of the present invention;

FIG. 2 is a Scanning Electron Microscope (SEM) image of a cross section of a silicon substrate;

FIG. 3 is a volume fraction of 15% Fe₃O₄@SiO₂Transmission electron microscopy images of the nanocomposite;

FIG. 4 is a schematic view of the drive field;

in the figure: the bending of the post is driven by a horizontal magnetic field generated by a vertically positioned magnet. The magnetic field strength is Adjusted by moving the magnet horizontally (i.e., changing the distance of the magnetic specimen).

FIG. 5 is a schematic view of a simplified model of bending of a microcolumn I;

in the figure: the particles in the microcolumn I are mainly distributed at the bottom of the microcolumn, and after a parallel magnetic field is applied, the microcolumn is mainly acted by force The method is concentrated at the bottom of the microcolumn, the microcolumn has small deformation, and the microcolumn is abbreviated as SDP.

FIG. 6 is a diagram showing the distribution of the elastic modulus and the load of the SDP microcolumn;

FIG. 7 is a schematic view of a simplified model of bending of a microcolumn II;

in the figure: the particles in the microcolumn II are mainly distributed on the top of the microcolumn, and after the parallel magnetic field is applied, the microcolumn is mainly acted by the acting force The micro-column is concentrated on the top of the micro-column, the micro-column is greatly deformed, and the micro-column is called L DP for short.

FIG. 8 is a graph showing the elastic modulus and load distribution of L DP microcolumn;

figure 9 is a schematic view of the operation principle of micro-tweezers picking.

Detailed Description

The invention is described in further detail below with reference to the figures and specific embodiments.