WO2022191450A1

WO2022191450A1 - Method for forming thin film on polymer-based artificial joint on basis of atomic layer deposition technique

Info

Publication number: WO2022191450A1
Application number: PCT/KR2022/002093
Authority: WO
Inventors: 송용남; 홍민표; 김경민
Original assignee: 고려대학교 산학협력단
Priority date: 2021-03-11
Filing date: 2022-02-11
Publication date: 2022-09-15
Also published as: KR20220128518A

Abstract

The present invention relates to a method for forming a thin film on a polymer-based artificial joint on the basis of an atomic layer deposition technique, the method comprising the steps of: (a) placing the artificial joint inside a chamber; (b) purging a first precursor containing a ceramic material into the chamber; and (c) purging a second precursor containing moisture into the chamber, wherein step (b) and step (c) are repeatedly performed a predetermined number of times of processes to form a thin film of the ceramic material on the surface of the artificial joint according to the atomic layer deposition technique. Therefore, an artificial joint with strong wear resistance can be produced by forming a ceramic-based thin film with strong wear resistance on a polymer-based material used for artificial joints through an atomic layer deposition technique.

Description

A method to form a thin film on a polymer-based artificial joint based on the atomic layer deposition technique

The present invention relates to a method of forming a thin film on a polymer-based artificial joint based on an atomic layer deposition technique, and more particularly, to a method for forming a thin film on a polymer-based artificial joint based on an atomic layer deposition technique to improve the mechanical properties of a polymer-based material used for an artificial joint. It relates to a method of forming a thin film on a polymer-based artificial joint.

The joints of the human body have ciliary tissue on their surface, so they have hydrophilicity that can store body fluids. Accordingly, the body fluid is stored in the ciliary tissue and functions as a lubricant to enable natural movement of the human joint.

The joints of the human body are one of the important organs that determine the overall shape and balance of the body and carry out the function of supporting weight among various parts of the human body. As much as that, the joint is frequently used and further exposed to frequent shocks, and aging progresses over time, or the function of the joint is weakened or lost due to various diseases or accidents.

Since such joint damage is difficult to treat in its natural state, the development of artificial joints that can replace damaged joints is steadily progressing. The quality of life has been significantly improved through such artificial joint surgery. The knee joint, shoulder joint, hip joint, and ankle joint are representative artificial joints.

1 is a view showing an example of a general artificial joint, showing an example of a knee joint. The knee joint is largely composed of a femoral element (3) replacing the articular surface of the distal end of the femur, a tibial element (5) replacing the articular surface of the proximal end of the tibia, and the femoral element (3) and the tibial element (5). a bearing element (1) having an articular surface in contact with the articular surface of the femoral element (3) while being positioned.

Here, the femoral element (3) is in contact with the bearing element (3) to make joint motion, the joint surface of the bearing element (3) usually has a surface made of a polymer-based material.

However, the polymer-based surface is abrasion-resistant in the course of joint motion with the femoral element 3, thereby reducing the lifespan of the artificial joint.

Accordingly, the present invention has been devised to solve the above problems, and by improving the mechanical properties of the polymer-based material used for artificial joints, a polymer based on the atomic layer deposition technique that can produce artificial joints that are strong against abrasion resistance. An object of the present invention is to provide a method for forming a thin film on a series of artificial joints.

The above object is, according to the present invention, in a method of forming a thin film on a polymer-based artificial joint based on an atomic layer deposition technique, (a) positioning the artificial joint in a chamber, (b) containing a ceramic material purging the first precursor into the chamber, and (c) purging the second precursor containing moisture into the chamber; In the atomic layer deposition technique, characterized in that the steps (b) and (c) are repeated as many times as the preset number of processes according to the atomic layer deposition technique to form the thin film of the ceramic material on the surface of the artificial joint It is achieved by a method of forming a thin film on a polymer-based artificial joint.

Here, (d) after performing step (b), before performing step (c), after performing step (c), and before performing step (b), purging the inert gas into the chamber may include more.

In addition, the ceramic material may include zinc oxide.

In addition, the first precursor may be DEZn ((C2H5)2Zn).

And, the second precursor may be distilled water.

In addition, the inert gas may include nitrogen or argon.

Here, the execution time of step (d) may be performed longer than the execution time of step (b) and step (c).

For example, the execution time of step (b) and step (c) may be 0.5 seconds, and the execution time of step (d) may be 30 seconds.

The method may further include preheating the temperature inside the chamber to a preset preheating temperature after performing step (a).

Here, the preheating temperature may be selected within the range of 100°C to 110°C.

In addition, it may further include the step of surface-treating the artificial joint before performing the step (a).

Here, the step of surface-treating the artificial joint comprises: polishing the surface of the artificial joint; washing the artificial joint by polishing; It may include plasma-treating the surface of the artificial joint.

And, the artificial joint may be a bearing element.

According to the above configuration, according to the present invention, a ceramic-based thin film strong in abrasion resistance is formed on a polymer-based material used for artificial joints through atomic layer deposition, so that an artificial joint strong in abrasion resistance can be produced. A method for forming a thin film on a polymer-based artificial joint based on a layer deposition technique is provided.

1 is a view showing an example of a general artificial joint,

2 is a view showing the process of a method of forming a thin film on a polymer-based artificial joint based on an atomic layer deposition technique according to an embodiment of the present invention;

3 to 9 are diagrams for explaining experimental results of a method of forming a thin film on a polymer-based artificial joint based on an atomic layer deposition technique according to an embodiment of the present invention.

The present invention provides a method for forming a thin film on a polymer-based artificial joint based on an atomic layer deposition technique, comprising: (a) positioning the artificial joint in a chamber; (b) a first precursor containing a ceramic material; purging into the chamber; (c) purging the second precursor containing moisture into the chamber; In the atomic layer deposition technique, characterized in that the steps (b) and (c) are repeated as many times as the preset number of processes according to the atomic layer deposition technique to form the thin film of the ceramic material on the surface of the artificial joint It is a method of forming a thin film on a polymer-based artificial joint.

Advantages and features of the present invention and methods of achieving them will become apparent with reference to the embodiments described below in detail in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but may be implemented in various different forms, and only these embodiments allow the disclosure of the present invention to be complete, and common knowledge in the technical field to which the present invention pertains It is provided to fully inform those who have the scope of the invention, and the present invention is only defined by the scope of the claims. Like reference numerals refer to like elements throughout.

Hereinafter, embodiments according to the present invention will be described in detail with reference to the accompanying drawings.

2 is a view showing the process of a method of forming a thin film on a polymer-based artificial joint based on an atomic layer deposition technique according to an embodiment of the present invention. In the embodiment of the present invention, it is exemplified that the polymer-based artificial joint is a bearing element constituting the artificial joint.

First, the artificial joint is introduced into the chamber (S11), and the artificial joint is positioned inside the chamber. Here, in the embodiment of the present invention, when the thin film is formed through the atomic layer deposition technique to be described later, for example, the process (S10) of surface-treating the surface of the artificial joint is included in order to secure the uniformity of the surface of the artificial joint. do.

For example, the surface treatment process according to an embodiment of the present invention includes a polishing process, a cleaning process, and a plasma treatment process.

The polishing process according to the embodiment of the present invention is exemplified by including a polishing process using a polishing equipment and a polishing process using a polishing cloth. In the polishing process by the polishing equipment, the surface treatment may be performed by rotating using sand paper, and the final polishing process may be performed through polishing using a polishing cloth.

The washing process according to an embodiment of the present invention is exemplified to include a primary washing process using ethanol and a secondary washing process using distilled water. Each washing process is performed for 10 minutes, and washing by applying ultrasonic waves is an example.

Between each process of the surface treatment as described above, it may include a process of removing fine particles generated from the surface through an air blow.

For the artificial joint after the cleaning process as described above, in an embodiment of the present invention, plasma treatment may be performed on the surface of the artificial joint. In an embodiment of the present invention, plasma processing is performed using a femto science plasma equipment as an example. Through this, a functional group is created on the surface of the artificial joint, and when a thin film is deposited on the surface of the artificial joint in a subsequent process, effective surface conditions can be created in the initial deposition process.

When the surface treatment process as described above is completed, the surface-treated artificial joint is introduced into the chamber of the ALD equipment for atomic layer deposition (S11), and the artificial joint is positioned inside the chamber.

In an embodiment of the present invention, before the formation of the thin film through the atomic layer deposition technique, it is exemplified that the process ( S12 ) of preheating the temperature inside the chamber to a preset preheating temperature is included.

Since the polymer-based material has relatively low thermal properties compared to a metal, a wafer, or a film, the deposition efficiency can be improved by maintaining the temperature inside the chamber at a preset preheating temperature. In an embodiment of the present invention, the preheating temperature is determined between 60°C and 145°C, preferably between 100°C and 110°C.

As described above, when the inside of the chamber is preheated to a preheating temperature, a process of forming a thin film on the surface of the polymer-based artificial joint by using the atomic layer deposition technique proceeds.

First, the first precursor containing the ceramic material is purged into the chamber (S13). In the present invention, zinc oxide is applied as a ceramic material as an example, and accordingly, a zinc oxide ceramic thin film may be formed on the surface of the artificial joint. In the present invention, DEZn ((C2H5)2Zn) is applied as the first precursor containing zinc oxide as an example.

Then, the inert gas is purged into the chamber (S14). Residual materials remaining in the chamber may be removed to the outside of the chamber through purging of the inert gas.

When the purging of the inert gas is completed, the second precursor containing moisture is purged into the chamber (S15). In an embodiment of the present invention, distilled water is applied as the second precursor as an example.

When the purging of the second precursor is completed, similarly, the inert gas is purged into the chamber ( S16 ), and the remaining materials remaining in the chamber are removed to the outside of the chamber. In the present invention, it is exemplified that nitrogen gas or argon gas is used as the inert gas.

In addition, in an embodiment of the present invention, it is exemplified that the time for purging the inert gas is longer than the time for purging the first precursor or purging the second precursor. As an example, it is assumed that the execution time of purging the first precursor and the second precursor is 0.5 seconds, and the execution time of purging the inert gas is applied as 30 seconds.

According to the atomic layer deposition technique in the process (S17) of performing the process as described above, that is, purging the first precursor, purging the inert gas, purging the second precursor, and purging the inert gas N times a preset number of processes A thin film of ceramic material can be formed on the surface of the artificial joint. In the present invention, it is exemplified that the above process is performed 1800 times.

Hereinafter, experimental results of a method for forming a thin film on a polymer-based artificial joint based on an atomic layer deposition technique according to an embodiment of the present invention will be described with reference to FIGS. 3 to 9 .

In the experiment, a UHMW-PE material was used as a polymer-based artificial joint, and a 10x10x6mm block-shaped specimen was used. As described above, the surface treatment process was performed, and after surface treatment was performed using a rotary type polishing equipment using sand paper #400, #800, #1600, #2400, the final polishing was performed using a polishing cloth. , Here, diamond suspension 1㎛ particles were used.

Then, washing was carried out using ultrasonic waves for 10 minutes in distilled water and 10 minutes in distilled water using isoethanol, and fine particles generated on the surface were removed through air blow between all processes. .

In addition, plasma treatment was performed using a femto science plasma equipment, and was performed under conditions of 100 W and 60 seconds. In the experiment according to an embodiment of the present invention, the preheating temperature inside the chamber was set to 60°C, 70°C, 80°C, 90°C, 100°C, 110°C, 120°C, 130°C, and 140°C, respectively.

At each preheating temperature, the deposition inside the chamber proceeded for 0.5 seconds for the first precursor, 30 seconds for the inert gas, and 0.5 seconds for the second precursor, and the first precursor, the inert gas, the second precursor, and the inert gas were combined into one After deposition for a total of 1800 cycles as a cycle, it was cooled to room temperature.

3 is an SEM image taken to confirm the thickness of the thin film at each preheating temperature. In the confirmation of the thin film thickness, if there is a section in which the thickness of the thin film is rapidly increased or rapidly decreased per cycle, it is possible to check a section in which the thin film formation rate is constant because the temperature at which the deposition becomes unstable.

4 is a graph showing the thin film growth rate according to the preheating temperature. The thin film growth rate rapidly increased according to the temperature in the range of 60°C to 90°C, confirming that the thin film formation was somewhat unstable in the corresponding temperature group. As a result of the experiment, it was confirmed that the thin film growth rate was stably performed in the section between 100 °C and 130 °C.

5 is an observation of the surface state of the thin film according to the preheating temperature, and is an image taken through SEM. 5 shows images observed at 60°C, 80°C, 90°C, 100°C, 110°C, and 140°C.

As shown in FIG. 5 , it can be confirmed that the size of the particles forming the thin film is not uniform between 60°C and 90°C. And, it can be seen that the particle size increases even at a high temperature of 140° C. and shows a non-uniform shape.

Accordingly, it was confirmed that the preheating temperature is preferably set between 100°C and 110°C in consideration of the growth rate of the thin film described above and the uniformity of the particle size of the surface as shown in FIG. 5 .

On the other hand, in order to measure the mechanical properties, a ball on disk wear equipment with rotational motion was used. An experiment was conducted using a ceramic-based Si₃N₄ ball (radius 6mm) as a counter part, which has relatively strong physical properties against abrasion and is currently used in artificial joints.

Experimental conditions were 3N vertical load, 60RPM speed, and 4mm eccentricity was applied so that the radius of the wear track was 4mm. The set experimental condition was 33 times greater than the contact pressure generated in the actual artificial joint, and the acceleration experiment was conducted under these conditions.

In order to check the wear performance of the thin film according to each sliding distance, a wear test was conducted by setting the conditions of 800, 1600, 3200, and 6400m sliding distance.

6 is a view showing an SEM image of a worn area as a result of a wear test. 6 (a) is a sliding distance of 800 m, FIG. 5 (b) is a sliding distance of 1600 m, FIG. 6 (c) is a sliding distance of 3200 m, FIG. 5 (d) is an SEM image at a sliding distance of 6400 m.

7 and 8 are views showing the results of confirming the chemical composition of the surface after the wear seal groove. 7A is a sliding distance of 800m, FIG. 7B is a sliding distance of 1600m, FIG. 8A is a sliding distance of 3200m, and FIG. 8B is a result of a sliding distance of 6400m. And, FIG. 9 is a view showing the ratio of zinc element, which is a thin film-forming material, according to the sliding distance.

As shown in FIG. 9 , it can be confirmed that the ratio of zinc element, which is a thin film forming material, is reduced according to the sliding distance, and it can be confirmed that a small amount is present up to 6400 m. Through this, it can be confirmed that up to 6400 mm, the zinc thin film withstands abrasion and protects the inner polymer-based material.

Although several embodiments of the present invention have been shown and described, it will be apparent to those skilled in the art that changes may be made to these embodiments without departing from the spirit or spirit of the invention. . The scope of the invention will be defined by the appended claims and their equivalents.

The present invention can be applied to the field of artificial joints used for joints of the human body.

Claims

In the method of forming a thin film on a polymer-based artificial joint based on the atomic layer deposition technique,

(a) positioning the artificial joint inside the chamber;

(b) purging the first precursor containing the ceramic material into the chamber;

(c) purging a second precursor containing moisture into the chamber;

In the atomic layer deposition technique, characterized in that the steps (b) and (c) are repeated as many times as the preset number of processes according to the atomic layer deposition technique to form the thin film of the ceramic material on the surface of the artificial joint A method of forming a thin film on a polymer-based artificial joint.
According to claim 1,

(d) after performing step (b), before performing step (c), after performing step (c), and before performing step (b), purging an inert gas into the chamber A method of forming a thin film on a polymer-based artificial joint based on an atomic layer deposition technique, characterized in that
3. The method of claim 2,

The method of forming a thin film on a polymer-based artificial joint based on the atomic layer deposition technique, characterized in that the ceramic material includes zinc oxide.
4. The method of claim 3,

The method of forming a thin film on a polymer-based artificial joint based on an atomic layer deposition technique, characterized in that the first precursor is DEZn ((C2H5)2Zn).
5. The method of claim 4,

The method of forming a thin film on a polymer-based artificial joint based on an atomic layer deposition technique, characterized in that the second precursor is distilled water.
5. The method of claim 4,

The inert gas is a method of forming a thin film on a polymer-based artificial joint based on an atomic layer deposition technique, characterized in that it contains nitrogen or argon.
5. The method of claim 4,

The method of forming a thin film on a polymer-based artificial joint based on an atomic layer deposition technique, characterized in that the execution time of the step (d) is performed for a long time for the steps (b) and (c).
8. The method of claim 7,

The execution time of step (b) and step (c) is 0.5 seconds,

A method of forming a thin film on a polymer-based artificial joint based on an atomic layer deposition technique, characterized in that the execution time of step (d) is 30 seconds.
5. The method of claim 4,

Method of forming a thin film on a polymer-based artificial joint based on an atomic layer deposition technique, characterized in that it further comprises the step of preheating the temperature inside the chamber to a preset preheating temperature after performing step (a).
10. The method of claim 9,

The preheating temperature is a method of forming a thin film on a polymer-based artificial joint based on an atomic layer deposition technique, characterized in that it is selected within the range of 100 ℃ to 110 ℃.
5. The method of claim 4,

Method of forming a thin film on a polymer-based artificial joint based on an atomic layer deposition technique, characterized in that it further comprises the step of surface-treating the artificial joint before performing step (a).
12. The method of claim 11,

The step of surface-treating the artificial joint is

polishing the surface of the artificial joint;

washing the artificial joint by polishing;

A method of forming a thin film on a polymer-based artificial joint based on an atomic layer deposition technique, comprising the step of plasma-treating the surface of the artificial joint.
According to claim 1,

The artificial joint is a method of forming a thin film on a polymer-based artificial joint based on an atomic layer deposition technique, characterized in that it is a bearing element.