JP3420270B2 - Method of manufacturing ultrasonic liquid transfer microtube - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a microtube such as a blood vessel of an artificial heart or a microtube of a micromachine, which is an ultrasonic liquid feeding microtube for feeding a liquid such as blood or a drug solution by ultrasonic driving . It relates to a manufacturing method .

[0002]

2. Description of the Related Art Conventionally, a small pump has been used as a means for sending blood in a blood vessel of an artificial heart. It has
Although there are reciprocating pumps, rotary pumps, centrifugal pumps, propeller pumps, jet pumps, and other structures, ultrasonic pumps are also being developed.

[0003]

In any case, according to the liquid feeding means in the conventional microtube, the small pump is used for driving the liquid feeding, so that a large space is taken and the size is reduced. Is not suitable for use, and because it produces a driving sound, it stimulates the nerves of the patient, especially when used as part of the body, such as an artificial heart, and also makes the pump operation unreliable. However, there is a problem that trouble is likely to occur and the functionality is poor.

Regarding the functionality, it is required that the flow rate can be adjusted and the flow direction can be freely changed, but neither of them can be dealt with by the small pump.

In view of the above situation, the present invention can smoothly and quietly send a liquid by ultrasonic waves without using a pump, and can easily adjust the flow rate and change the flow direction. Of ultrasonic liquid delivery micro tube
Aimed to provide the law .

[0006]

A method for manufacturing an ultrasonic liquid feeding microtube according to the present invention for achieving the above object.
The method is to send the liquid in the microtube by ultrasonic drive.
In the method of manufacturing an ultrasonic liquid feeding microtube,
A certain number of traveling wave generators on the outer peripheral surface of the microtube.
Providing a continuous wave at intervals, of which the traveling wave generator is manufactured
For, regarding the outer circumference of the tube, first apply and burn the lower electrode.
And then apply a piezoelectric material on it as an ultrasonic wave generation layer.
Apply a cloth and bake, and then apply and bake the upper electrode on it.
And are characterized.

[0007] In the method of manufacturing the ultrasonic liquid transfer microtubes for continuous multiple traveling wave generating unit at predetermined intervals, the production of the traveling wave generating unit, by provisionally inserting the core, retains its shape On the outer peripheral surface of the flexible tube, a carbon paste is applied and baked as a lower electrode, a piezoelectric material is applied and baked as an ultrasonic wave generation layer on it, and a carbon paste is applied and baked as an upper electrode on it. Characterize.

Further , in another manufacturing method, for manufacturing the traveling wave generating section, an aluminum tube is used as a lower electrode, and a piezoelectric material is applied as an ultrasonic wave generating layer on the outer peripheral surface thereof.
It is characterized in that it is baked, and a carbon paste is applied and baked thereon as an upper electrode.

[0009]

[Operation] Since the method of manufacturing the ultrasonic liquid feeding microtube is configured as described above, when electricity of a predetermined frequency is applied to each continuous traveling wave generating portion, the wavelength and the pitch of the traveling wave generating portion are separated from each other. In relation, the liquid is driven in one direction within the tube.

Further, when the tube of the traveling-wave generating unit is flexible, it is to be reinforced by the core, it is possible to easily form the coating of each layer of the traveling-wave generating unit, a baking (claim 2).

Further , when the tube of the traveling wave generating section is made of aluminum, it is used as the lower electrode, so that the material is not used much and the manufacturing is facilitated (claim 3) .

[0012]

Embodiments of the present invention will now be described with reference to the drawings.

FIG. 1 is a diagram for basically explaining an ultrasonic liquid feeding microtube according to an embodiment of the present invention, in which a large number of traveling wave generating portions T, T, ... Are flexible joint tubes 1a, 1a. , ..., the liquid is driven in one direction mainly in relation to the wavelength of the used frequency and the pitch between the traveling wave generators T, T, and in the configuration of the traveling wave generator T, the tube 1 (Or 2) is directly applied to the outer periphery and baked.

Therefore, it is not necessary to crush the tube in order to increase the contact surface with the piezoelectric material whose polarization direction is reversed at a pitch of ½λ of the frequency used, and the tube is directly formed on the outer peripheral surface of the tube. It is possible. Further, if a silicon tube is used as the tube, the acoustic impedance is closer to that of silicon rubber than that of the ceramic sintered body, so that the traveling wave propagation loss is small.

2 and 3 show an example method of the traveling wave generating portion T, in which the tube 1 is made of a flexible silicone rubber having an inner diameter of 1.0 mm and a wall thickness of 0.3 mm. For the ultrasonic wave generation layer 3, a polymer piezoelectric material developed by the present applicant was used.

FIGS. 3A to 3F show the procedure of the manufacturing method of one embodiment . First, as shown in FIG.
A piano wire is inserted as the core material 5 into the silicon rubber tube 1 so as not to be deformed, and then a film 7 is formed on the outer peripheral surface as a pretreatment. Regarding the formation of the film 7, a flexible epoxy resin to which a thickening agent (reolo-zil) is added is applied and cured.

A lower electrode 9 is formed on the film 7, as shown in FIG. To do this, apply carbon paste and bake. Here, if it is applied thickly and cured at one time, wrinkles will be generated on the surface, and therefore repeated thin coatings are repeated. An ultrasonic wave generation layer 3 is laminated thereon as shown in (c).

For the ultrasonic wave generation layer 3, lead zirconate titanate (referred to as PZT) or the like is used as a piezoelectric material. Since it does not defoam, apply this thinly many times and bake each time. PZT is a ferroelectric ceramic that exhibits a piezoelectric effect, and a piezoelectric material is made by dispersing it in a cured composition at a predetermined ratio. Various properties such as impact resistance, adhesiveness, and heat resistance can be obtained depending on the material of the cured composition.

Examples of such a curable composition include an epoxy resin having two or more epoxy groups in the molecule, two or more amino groups, two or more benzene rings, and two or more carbonyl groups in the molecule. And a compound having two or more groups in which four or more methylene groups are connected and each group having a linear array and a cross-linking agent for epoxy resin are cross-linked. (Japanese Patent Laid-Open No. 1-66)
229 and JP-A-1-67986). In this case, the ratio of PZT is 70 to 90.
%.

Since air bubbles may float on the surface of the ultrasonic wave generating layer 3, as a pretreatment, as shown in (d), a flexible epoxy resin is again applied and cured to form a film 11. After forming, the upper electrode 13 is formed as shown in (e). This upper electrode 1
3 is also formed by applying a carbon paste and baking.

As shown in (f), the lead lines 15 and 17
Thereby, the lower electrode 9 is polarized and the upper electrode 13 is polarized. Thereby, the traveling wave generator T is formed.

As shown in FIG. 1, when a current of a certain frequency is passed between the lower electrode 9 and the upper electrode 13 in a state where the traveling wave generating portions T are chained, the ultrasonic wave generating layer 3 becomes By vibrating in frequency and generating high frequency,
The liquid in the tube 1 moves in one direction. And +,
If-is reversed, the direction of movement is reversed. Further, the flow velocity of the liquid can be changed by changing the current or voltage. The connection pitch of the traveling wave generator T is determined by the driving frequency, the viscosity of the fluid used, the propagation speed of the silicon tube, and the like.

FIG. 4 shows another embodiment in which the traveling wave generating portion T is formed by applying the ultrasonic wave generating layer 3 to the tube 2 of an aluminum tube having a diameter of 2.00 mm as described above. The upper electrode 13 is formed of carbon paste, but the lower electrode 9 is the aluminum tube 2.

As for the manufacturing method, since the tube 1 has strength, after forming the laminated structure of the traveling wave generating portion T on the long member as described above, it is cut to a predetermined length and cut at both ends. The tube 1 is exposed and the lead wires 15 and 1
Attach 7.

The curing conditions for the materials used in each of the above examples are as follows. Flexible epoxy resin 160 ° C (1 hour) Piezoelectric material 160 ° C (1 hour) Carbon paste 150 ° C (5 seconds)

[0026]

As described above, the manufacturing method according to the present invention
According to the ultrasonic liquid feeding microtube that is, without the use of pumps, for liquid is fed by ultrasonic wave in the traveling-wave generating portion of the tube forms which are arranged at a predetermined pitch, not take much space, Artificial hearts, micromachines, etc. can be made compact. Further, not only is there comfort without driving noise, but also it is easy to adjust the flow rate of the liquid and change the flow direction, and there is an excellent effect that it can be used conveniently and without trouble.

Further, according to the manufacturing method of the present invention, and the
It is suitable for manufacturing an ultrasonic liquid feeding microtube, and even if the tube of the traveling wave generating portion is flexible (claim 2), each layer can be easily formed by coating and baking. Further, when the tube of the traveling wave generating part is aluminum (claim 3), it can be used as the lower electrode, so that the material is not used much and the manufacturing becomes easy.

[Brief description of drawings]

FIG. 1 is an explanatory view showing an ultrasonic liquid feeding microtube according to the method of the present invention.

FIG. 2 is an explanatory diagram showing a cross-sectional structure of a traveling wave generation unit that constitutes an ultrasonic liquid feeding microtube.

3A and 3B are explanatory views showing a method of manufacturing the traveling wave generation unit of FIG. 2 in the order of (a) to (f).

FIG. 4 is an explanatory view showing a cross-sectional structure of a traveling wave generating portion showing another embodiment.

[Explanation of symbols]

T traveling wave generator 1, 2 tubes 3 Ultrasonic wave generation layer 5 heartwood 9 Lower electrode 13 Upper electrode

Claims (3)

(57) [Claims] 1. A liquid in a microtube is ultrasonically driven.
The method of manufacturing ultrasonic liquid feeding microtubes
Multiple traveling wave generators around the microtube.
It is provided continuously at a predetermined interval, of which the traveling wave generator
For manufacturing the
Apply and bake, then apply pressure as an ultrasonic wave generation layer on it.
Apply and bake electric material, and then apply and bake the upper electrode
Of the ultrasonic liquid feeding microtube characterized by
Production method. 2. In a method of manufacturing an ultrasonic liquid feeding microtube in which a plurality of traveling wave generating portions are continuous at a predetermined interval, regarding the manufacturing of the traveling wave generating portion, the shape is maintained by temporarily inserting a core material. On the outer peripheral surface of the flexible tube, a carbon paste is applied and baked as a lower electrode, a piezoelectric material is applied and baked as an ultrasonic wave generation layer on it, and a carbon paste is applied and baked as an upper electrode on it. A method for producing a characteristic ultrasonic liquid feeding microtube. 3. In a method of manufacturing an ultrasonic liquid feeding microtube in which a plurality of traveling wave generating portions are continuous at a predetermined interval, regarding the manufacturing of the traveling wave generating portion, an aluminum tube is used as a lower electrode, and an outer peripheral surface thereof is A method for producing an ultrasonic liquid feeding microtube, comprising applying a piezoelectric material as an ultrasonic wave generating layer, baking the same, and then applying and baking a carbon paste as an upper electrode thereon.