JP2008286528A - Microknife and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a microknife having such thinness as to easily specify a cutting location and provide a microknife manufacturing method which enables the easy manufacture of such microknives. <P>SOLUTION: A cutting blade is made of a crystal material manufactured by a micromachining process. A part of a silicon substrate is etched to a depth corresponding to the thickness of the cutting blade from the front and back surfaces of the silicon substrate to form a groove having a depth corresponding to the thickness of the cutting blade. The thickness of a blade of an end item is adjusted by the depth of the groove. Then etching is performed from the back surface of the silicon substrate. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a microknife used for cutting cells, eggs, microorganisms, and the like, and a microknife manufacturing method for manufacturing such a microknife. In particular, the blade thickness is thinner than the diameter of a fine cell or the like. The present invention relates to a device devised so that it can be easily cut and can be cut without damaging cells during operation under a microscope.

  In the field of biology, part of an unfertilized egg is cut or a fertilized egg is divided in order to perform sex determination of an egg or to make a cloned animal. In the medical field, in order to cut out proteins including DNA / RNA and the like for the identification of pathogenic bacteria, cells / tissues are cut and processed.

  FIG. 7 shows how such cells are cut and processed. As shown in FIG. 7A, a cell 105 is contained in a spot 103 made of physiological saline or the like, and the cell 105 is cut by a knife 101. The knife 101 has a thin wall shape obtained by polishing a metal blade. The state of the cutting / processing is shown in FIG.

For example, Patent Literature 1 and Patent Literature 2 disclose prior art.
Japanese Patent Laid-Open No. 11-138494 JP 2004-141360 A

The conventional configuration has the following problems.
First, the diameter of the cell 105 is generally about several μm to several hundred μm. For example, the diameter of an unfertilized egg such as a cow is about 120 μm. On the other hand, in the case of a metal knife 101 obtained by processing and polishing a conventional metal, the thickness is equal to or greater than the diameter of the cell 105. For this reason, there is a problem that the cutting position of the cell 105 cannot be specified even if it is cut under a microscope.
Further, when excising tissue, nucleus, DNA, etc. contained in the cell 105, it is necessary to cut the zona pellucida so as not to destroy the tissue, nucleus, DNA, etc. as much as possible. For that purpose, it is necessary to have a sufficiently sharp blade edge, and in order to accurately separate tissues, nuclei, DNA, etc., it is necessary to prevent the zona pellucida protein from adhering to the blade edge. However, this is not possible with the conventional knife 101.

  The present invention has been made to solve such problems, and the object of the present invention is to provide a microknife having a cutting knife that is thin enough to easily identify the cutting position, and such a microknife. It is an object of the present invention to provide a microknife manufacturing method that can be easily manufactured.

In order to solve the above problem, a microknife according to claim 1 of the present invention is characterized in that the cutting blade is made of a crystalline material manufactured by a micromachining process.
A microknife according to claim 2 is characterized in that, in the microknife according to claim 1, the cutting blade and the support are integrally formed by a series of micromachining processes.
According to a third aspect of the present invention, in the microknife according to the first aspect, the cutting edge radius of the cutting blade is 200 nm or less.
According to a fourth aspect of the present invention, there is provided the microknife according to the first aspect, wherein the cutting edge of the cutting blade is amorphized by oxidation treatment.
A micro knife according to claim 5 is the micro knife according to claim 1, wherein the cutting blade is made of single crystal silicon.
According to a sixth aspect of the present invention, there is provided the microknife according to the first aspect, wherein the microknife is for cutting a living body such as a cell or tissue.
According to a seventh aspect of the present invention, there is provided the microknife according to the first aspect, wherein the cutting edge of the cutting blade is formed with a crystal orientation.
Further, the microknife according to claim 8 is etched from the back and front of the silicon substrate as much as the thickness of the cutting blade, and a groove having a depth corresponding to the thickness of the cutting blade is formed in the etched portion of the silicon substrate. It is formed, the thickness of the blade of the final product is adjusted by the depth of the groove, and then etched from the back surface of the silicon substrate.

As described above, according to the microknife according to claim 1 of the present invention, the cutting blade is made of a crystalline material manufactured by the micromachining process, so that the blade thickness can be easily reduced. , A strong cutting blade can be obtained. Moreover, many microknives can be obtained at once.
Further, according to the microknife according to claim 2, in the microknife according to claim 1, since the cutting blade and the support are integrally formed by a series of micromachining processes, the cutting blade is fixed to the support. There is an advantage in that no special work or structure is required.
Moreover, according to the microknife according to claim 3, in the microknife according to claim 1, since the cutting edge radius of the cutting blade is 200 nm or less, the shadow of the microknife cannot be formed when the cutting operation is performed under an optical microscope. The work is not hindered by shadows.
Further, according to the microknife according to claim 4, in the microknife according to claim 1, since the cutting edge of the cutting blade is amorphized by oxidation treatment, protein adhesion can be prevented, and cutting is performed under a microscope. When working, it can be operated well.
Further, according to the microknife according to claim 5, in the microknife according to claim 1, since the cutting blade is made of single crystal silicon, the cutting edge of the cutting blade is amorphized by oxidation treatment. Can be made to have a very acute angle, and cells and tissues can be easily cut.
Moreover, according to the microknife according to claim 6, since the microknife according to claim 1 is used for cutting a living body such as a cell or tissue, it exhibits an excellent effect on cutting the living body.
Further, according to the microknife according to claim 7, in the microknife according to claim 1, since the cutting edge of the cutting blade is formed by the crystal orientation, a sharp microknife can be easily obtained.
According to the microknife manufacturing method of claim 8, etching is performed from the front and back sides of the silicon substrate as much as the thickness of the cutting blade, and the depth corresponding to the thickness of the cutting blade is formed in the portion of the silicon substrate that has been dug. Are formed, and the thickness of the blade of the final product is adjusted by the depth of the groove, and then etched from the back surface of the silicon substrate to constitute a microknife. Many sheets can be manufactured.

  Hereinafter, an embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a perspective view showing a configuration of a microknife 1 according to the present embodiment. The microknife 1 includes a cutting blade 3 having a thickness of 30 μm and a support 5 having a thickness of 220 μm that supports the cutting blade 3. The support 5 functions as a fixing part for attaching the microknife 1 to a holder 7 (shown in FIG. 3).

  The cutting blade 3 is made of a crystalline material, and is formed by a micromachining process. As the material of the cutting blade 3, any material can be used as long as it is strong and can be processed by a micromachining process, and is a crystalline material. Among them, single crystal silicon is preferable.

The cutting blade 3 and the support 5 are integrally formed as described above, and the cutting blade 3 is made of the same material as the support 5 and is thinner than the support 5. ing. Since the thickness of the cutting blade 3 is formed thinner than the thickness of the support 5, the usability at the time of cutting is good.
The material of the holder 7 may be anything as long as it can be joined to the support 5.

  Next, with reference to FIG. 2, the manufacturing process of the microknife 1 according to the present embodiment will be described. FIG. 2 is a diagram showing the state of FIG. 1 viewed from the Z direction in the order of the manufacturing process. In FIG. 2, reference numeral 11 denotes an oxide film, reference numeral 13 denotes a pattern mask, reference numeral 15 denotes single crystal silicon, and reference numeral 16 denotes a positive resist.

  First, as shown in FIG. 2A, a single crystal silicon substrate 15 that is covered with a natural oxide film and has a diameter of 4 inches, a thickness of 220 μm, and a (100) plane orientation is placed in an electric furnace (not shown). Thereby, the oxide film 11 is grown on the surface of the silicon substrate 15 in the range of 0.2 to 0.7 μm.

  Next, as shown in FIG. 2B, the positive resist 16 is uniformly applied to the surface of the silicon substrate 15 by a spin coater.

Next, as shown in FIG. 2 (c), a pattern mask 13 having a knife plane shape as shown in the perspective view of FIG. Etching is performed with an aqueous solution of TMAH (tetramethylammonium hydroxide) or an alkaline solution such as KOH (potassium hydroxide) so as to be thick, thereby forming a 30 μm groove. This is shown in FIG.

  Next, as shown in FIG. 2E, the silicon substrate 15 is put into an electric furnace (not shown), and a reoxidized film 11 'is grown on the surface in a range of 0.2 to 0.7 μm.

Next, as shown in FIG. 2F, the silicon substrate 15 etched on one side is inverted. Next, as shown in FIG. 2G, a positive resist 16 is uniformly applied to the back surface of the silicon substrate 15 by a spin coater. Then, patterning is performed using the back surface pattern mask 13 ′ aligned with the previously used pattern mask 13.

  Thereafter, a knife is formed by etching with a TMAH (tetramethylammonium hydroxide) aqueous solution until the silicon substrate 15 penetrates around the knife shape.

Next, as shown in FIG. 2I, the silicon substrate 15 is placed in an electric furnace (not shown), and a reoxidized film 11 ′ is grown on the surface by 1 μm. And it promotes the amorphization of the crystal by thermal diffusion and improves the precision of the cutting edge.

Finally, as shown in FIG. 2 (j), the oxide film 11 ′ is removed to form a microknife 1 having a blade thickness of 30 μm.

  Then, as shown in FIG. 3, the obtained microknife 1 is inserted into a holder 7 that has been previously grooved in accordance with the thickness of the support 5 and fixed using an adhesive.

  Next, as shown in FIG. 3, the obtained microknife 1 is used to cut and process the cells. That is, the microknife 1 was attached to the tip of the manipulator hand 21 via the holder 7 to cut and process the livestock embryo cells 23. The embryo cell 23 is contained in the spot 27 in the petri dish 25.

  FIG. 4 shows a photograph of a state in which the embryonic cell 23 is cut and processed by the microknife 1 through the objective lens 29, and a continuous photograph obtained thereby is shown in FIG. 4 (a) to 4 (c) sequentially show how the embryonic cell 23 is cut by the microknife 1. FIG. FIG. 4D shows a state in which the cutting has been completed. For the bovine embryo cell 23 having a diameter of about 120 μm, the macro knife 1 having a thickness of 30 μm has good visibility of the target cell, does not damage the tissue 30 of the embryo cell 23, and does not adhere to the protein. It turns out that it can cut | disconnect favorably.

As described above, according to the present embodiment, the following effects can be obtained.
First, since the microknife 1 is made of a crystalline material manufactured by a micromachining process, particularly a single crystal silicon material, the blade thickness can be easily reduced, and a strong cutting blade is obtained. be able to. As a result, the cell 23 can be easily cleaved without damaging the cell 23 and without causing protein adhesion.
Moreover, many microknives 1 can be obtained at once.
Further, in the microknife 1, the cutting blade 3 and the support 5 are integrally formed by a series of micromachining processes. Therefore, special work is required to fix the cutting blade 3 to the support 5. And not.
Moreover, in the microknife 1 according to the present embodiment, the cutting edge 3 has a cutting edge radius of 200 nm or less, so that the cutting blade 3 can be easily made thin. When the cutting operation is performed under the optical microscope, the shadow of the microknife 1 cannot be formed, and the operation is not hindered by the shadow.
Further, in the microknife 1 according to the present embodiment, the cutting edge of the cutting blade 3 is amorphized by oxidation treatment, so that the tip of the blade can be made to have a very acute angle by oxidation treatment.
In addition, protein adhesion can be prevented, and when the cutting operation is performed under a microscope, the operation can be favorably performed.
In addition, since the cutting edge 3 of the microknife 1 according to the present embodiment is formed with a crystal orientation, a sharp microknife can be easily obtained.
Further, in the case of the present embodiment, etching is performed from the front and back of the silicon substrate as much as the thickness of the cutting blade, and a depth corresponding to the thickness of the cutting blade 3 is formed in the portion where the silicon substrate is dug. A groove is formed, the thickness of the blade of the final product is adjusted according to the depth of the groove, and then etching is performed from the back surface of the silicon substrate to form a microknife. Many silicon substrates can be manufactured at one time.

In the case of the first embodiment, the reoxidation process is performed at the stage of manufacturing the microknife 1. On the other hand, the microknife 1 may be obtained without performing such reoxidation treatment, and such a microknife 1 is also within the scope of the present invention.
However, in this case, as shown in FIG. 5, when the cell 23 is to be cut by the microknife 1, the tissue 30 in the cell 23 may protrude or jump out due to poor cutting.
On the other hand, when the re-oxidation process is performed at the stage of manufacturing the microknife 1 as in the case of the first embodiment, it is possible to reliably prevent such cutting defects.

Next, a second embodiment of the present invention will be described with reference to FIG. In the case of the first embodiment, the shape of the cutting blade 3 is a sharp triangular shape. In the case of the second embodiment, this is a flat shape. In this way, by designing the pattern mask, various shapes of microknives can be easily formed, and microknives with a high degree of freedom can be obtained in accordance with usage patterns.
Other configurations are the same as those of the first embodiment, and the same parts are denoted by the same reference numerals and description thereof is omitted.
Therefore, in this case as well, the same effect as in the case of the first embodiment can be obtained.

The present invention is not limited to the first and second embodiments.
First, the shape and size of the microknife are not particularly limited.
In the case of the first and second embodiments, the configuration in which the cutting blade 3 and the support 5 are integrated has been described as an example, but separate cases are also conceivable.
In addition, the illustrated configuration is merely an example.

  The present invention relates to a microknife used for cutting cells, eggs, microorganisms, and the like, and a microknife manufacturing method for manufacturing such a microknife. In particular, the blade thickness is thinner than the diameter of a fine cell or the like. For example, in the field of biology, sex determination of eggs or creation of cloned animals is made with respect to things devised so that cells can be cut without damaging cells when operated under a microscope. Suitable for research.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing an overall configuration of a microknife, showing a first embodiment of the present invention. It is a figure which shows the 1st Embodiment of this invention, and is a figure which shows the state which looked at FIG. 1 from the Z direction in order of the process of the manufacturing method of a microknife. It is a figure which shows the 1st Embodiment of this invention, and is a perspective country which shows a mode that an embryonic cell is cut | disconnected using a microknife. It is a figure which shows the 1st Embodiment of this invention, and is the figure which photographed a mode that the aspect which cut | disconnects the embryo cell of livestock with a microknife in order, and made it into drawing. It is a figure which shows the 1st Embodiment of this invention, and is the figure which photographed sequentially a mode that it cut | disconnects with the microknife which has not performed the reoxidation process, and made it into drawing. It is a figure which shows the 2nd Embodiment of this invention, and is a perspective view which shows the structure of the whole microknife. FIG. 7 (a) is a plan view showing a state before cell processing, and FIG. 7 (b) is a plan view showing a state of cell processing.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Micro knife 3 Cutting blade 5 Support body 7 Holder 11 Oxide film 11 'Re-oxidation film
13 Pattern mask 13 'Back pattern mask 15 Silicon substrate 16 Positive resist 21 Manipulator hand 23 Embryonic cell 25 Petri dish 27 Spot 29 Objective lens
30 cell tissue

Claims (8)

A microknife characterized in that the cutting blade is made of a crystalline material manufactured by a micromachining process. The microknife of claim 1, wherein
A microknife characterized in that the cutting blade and the support are integrally formed by a series of micromachining processes. The microknife of claim 1, wherein
A microknife having a cutting edge radius of the cutting blade of 200 nm or less. The microknife of claim 1, wherein
A microknife characterized in that the cutting edge of the cutting blade is amorphized by oxidation treatment. The microknife of claim 1, wherein
A microknife characterized in that the cutting blade is made of single crystal silicon. The microknife of claim 1, wherein
A microknife for cutting a living body such as a cell or tissue. The microknife of claim 1, wherein
A microknife characterized in that the cutting edge of the cutting blade is formed by a crystal orientation. Etching is performed from the front and back of the silicon substrate as much as the thickness of the cutting blade, and a groove having a depth corresponding to the thickness of the cutting blade is formed in the dug portion of the silicon substrate. A method of manufacturing a microknife, comprising adjusting the thickness of the blade and then etching from the back surface of the silicon substrate.

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