RU2704358C1 - Method of making volumetric micro-dimensional nanoparticle structures and device for its implementation - Google Patents

Abstract

FIELD: nanotechnologies.

SUBSTANCE: group of inventions relates to additive production of volumetric micro-dimensional structures from nanoparticles by sintering nanoparticles on a substrate. An aerosol stream with nanoparticles is obtained in a pulse-periodic gas discharge in a stream of transport gas, followed by heating the aerosol with nanoparticles in a stream of transport gas to obtain spherical particles of the required size, obtained aerosol flow with nanoparticles is transported to the head with the nozzle to focus it on the substrate, an aerosol stream with nanoparticles is fed into said nozzle and simultaneously the protective gas is provided so that nanoparticle aerosol flow on the substrate is focused and nanoparticles are deposited from the focused aerosol flow onto the substrate. Deposition and sintering of nanoparticles on substrate are carried out in protective gas atmosphere, which is created under nozzle. Disclosed is a device for implementing said method.

EFFECT: enabling production of qualitative volumetric micro-dimensional structures with improvement of sanitary-hygienic conditions of production.

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Description

The invention relates to additive 3D technology for the production of predominantly bulk micro-sized structures from nanoparticles, which are used in electronics, photonics, medical, aerospace engineering and other fields.

A known method and device for the manufacture of bulk structures by sequentially depositing layers of particles of magnetic material using a heating device, a deposition device, a support and a mask through which particles are deposited. The disadvantages of these technical solutions is that it requires the use of special masks for the deposition of particles, which leads to additional costs for their manufacture and loss of particles on the surface of the mask [1].

A known method of manufacturing bulk structures of nanoparticles using nanoparticles, including obtaining an aerosol stream with nanoparticles, transporting the stream to the nozzle of the head, focusing and deposition of nanoparticles from the aerosol stream on a substrate, followed by sintering of arrays of deposited nanoparticles [2, 3].

There is also known a device for implementing this method, including a unit for receiving an aerosol stream with nanoparticles, connected to a source of transport gas, a head with a nozzle connected to an unit for receiving an aerosol stream, a substrate, and a sintering device for deposited nanoparticle arrays on a substrate [2, 3].

These technical solutions make it possible to fabricate bulk structures from nanoparticles. However, when using them, difficulties arise with the preparation of nano-ink, such as the selection of solvents and stabilizers. At the same time, there are special requirements for the conditions of their storage and transportation.

As a result of the use of solvents and stabilizers in nano-ink, environmental pollution occurs. After the use of nano-ink, the removal of solvents and stabilizers from the resulting bulk structures from nanoparticles is required. The relatively high cost of nano-ink leads to an increase in the cost of manufacturing bulk structures from nanoparticles. When using this method, the nozzles become clogged with large microdrops.

The result, to which this technical solution is directed, is the possibility of manufacturing bulk micro-sized structures from nanoparticles of the required quality without the use of nano-ink while improving sanitary and hygienic conditions of production.

This result is achieved due to the fact that in the method of manufacturing bulk micro-sized structures from nanoparticles, which includes obtaining an aerosol stream with nanoparticles, transporting the stream to the nozzle of the head, focusing and deposition of nanoparticles from the aerosol stream onto a moving substrate, followed by sintering of the deposited nanoparticle array, obtaining an aerosol stream with nanoparticles is carried out in a pulse-periodic gas discharge in the flow of transport gas, before transporting the flow to the nozzle of the head produce about By optimizing the size, shape and chemical composition of nanoparticles by heating them in a transport gas stream, by supplying an additional protective gas stream to the head under a nozzle, a protective gas atmosphere is created in which focusing, deposition and sintering of an array of deposited nanoparticles are carried out. When optimizing the size, shape and chemical composition of the nanoparticles, a reactive gas may additionally be supplied. Sintering an array of deposited nanoparticles can be performed by a focused laser beam, with the beam focusing at a distance L from the axis of the nozzle, taken in accordance with the expression L = TV, where T is the time of formation of an array of deposited nanoparticles, V is the relative velocity of the substrate.

This result is achieved due to the fact that in the device for the manufacture of volumetric micro-dimensional structures from nanoparticles, including a block for receiving an aerosol stream with nanoparticles, connected to a source of transport gas, a head with a nozzle, a substrate, and a sintering device on an array substrate connected to the block for receiving an aerosol stream deposited nanoparticles, it is equipped with an optimization unit containing a heating element, the input of which is in communication with the aerosol flow receiving unit with nanoparticles, and the output with the head and nozzles m. The second input of the optimization unit may be in communication with the source of reactive gas. The sintering device can be made in the form of a laser-optical device. A device for manufacturing bulk micro-sized structures from nanoparticles can also be additionally equipped with a coordinate table with which the substrate is attached, and the optical axis of the laser-optical device is placed in a plane passing through the axis of the nozzle.

An example of the implementation of the claimed technical solution is illustrated by drawings, where in FIG. 1 and 2 show the claimed device, in FIG. 3 shows a graph of the distribution of particle concentration depending on their diameter before (a) and after (b) the optimization block, in FIG. 4 is a photograph of silver nanoparticles from a transmission electron microscope; FIG. 5 is an optical image of arrays of deposited silver nanoparticles on a glass substrate; FIG. 6 is a raster electron microscopic image of the profile of a volumetric micro-dimensional structure from a sintered array of deposited silver nanoparticles on a glass substrate.

A device for manufacturing volumetric micro-dimensional structures from nanoparticles, includes an aerosol stream receiving unit with nanoparticles 1 connected to a transport gas source 2, a head 3 connected to an aerosol receiving unit, with a nozzle 4, a substrate 5, and a laser-optical device 6 for sintering on a substrate array of precipitated nanoparticles 7.

The device is equipped with an optimization unit 8 containing a heating element 9. The input 10 of the optimization unit 8 is in communication with the aerosol flow receiving unit 1 with nanoparticles, and its output 11 is connected to the head 3 and nozzle 4. The second input 12 of the optimization unit is connected to the source 13 of reactive gas. The head 3 is in communication with a source of shielding gas 14.

The device is also equipped with a coordinate table 15, with which the substrate 5 is fixed. The optical axis 16 of the laser-optical device 6 is placed in a plane passing through the axis 17 of the nozzle. The head 3 is in communication with a source of shielding gas 14.

A method of manufacturing bulk micro-dimensional structures of nanoparticles is as follows.

Transport gas from source 2 is supplied to an aerosol stream with nanoparticles receiving unit 1, where an aerosol with nanoparticles is produced in a pulse-periodic gas discharge. This process occurs due to electrical erosion of the electrode material.

The resulting aerosol with nanoparticles enters the optimization unit 8, which optimizes the size, shape and chemical composition of the nanoparticles. The optimization of the size and shape of the nanoparticles occurs due to their heating in the flow of transport gas, and the optimization of the chemical composition of the nanoparticles, if necessary, is carried out through the use of reactive gas, which is selected in accordance with the material of the nanoparticles.

After optimization block 8, the aerosol with nanoparticles is fed to the head 3 with the nozzle 4, into which, at the same time, a protective gas is supplied from the source 14, due to which the nanoparticles are focused from the aerosol stream at the nozzle section 18, and a focused beam 19 is formed at its exit nanoparticles, which is deposited on a substrate 5 that is movable relative to the nozzle 4.

In this example, the substrate 5 is fixed on the coordinate table 15, however, the head 3 with the nozzle 4 can move relative to the substrate.

Sintering an array of 7 deposited nanoparticles on a substrate 5 is performed by a focused beam 20 of a laser-optical device 6 in a gas protective atmosphere 21, while the focus 22 of the focused beam 20 is located at a distance L from the nozzle axis 17, taken in accordance with the expression L = TV, where T is the time of formation of an array of deposited nanoparticles, V is the relative velocity of the substrate.

An example of the method.

In block 1 for obtaining an aerosol stream with nanoparticles, silver was used as the material. In a repetitively pulsed gas discharge in a transport gas stream, nanoparticles were obtained which were optimized in optimization block 8.

In FIG. Figure 3 shows a graph of the distribution of particle concentration depending on their diameter before (a) and after (b) the optimization block. The graph is obtained as a result of measurements using an aerosol spectrometer. Aerosol silver nanoparticles are obtained in a periodic pulsed gas discharge in a transport gas stream as a result of electrical erosion of silver electrodes.

The graph shows that after passing through the optimization block, the particle size and concentration decreases, since the obtained non-optimized silver nanoparticles in the form of agglomerates during sintering in the optimization block become more compact and spherical, and their number decreases. This conclusion is confirmed by the data shown in FIG. 4, where the photograph of silver nanoparticles with a transmission electron microscope shows that with an increase in the optimization temperature from 25 to 750 ° C, the obtained non-optimized silver nanoparticles in the form of agglomerates transform into spherical nanoparticles with an increase in the temperature of the optimization block, and their number decreases.

Spherical nanoparticles, in contrast to irregularly shaped agglomerates, are more efficiently focused in the head with a nozzle and make it possible to obtain smaller-scale arrays of deposited nanoparticles on a substrate.

This is confirmed by the representation of FIG. 5, by optical images of arrays of deposited silver nanoparticles on a glass substrate, obtained without (a) and (b) using an optimization unit. As seen in FIG. 5, the use of an optimization unit allows one to obtain smaller-scale arrays of deposited nanoparticles with uniform boundaries (Fig. 5b), in contrast to arrays of deposited nanoparticles obtained without an optimization block (Fig. 5a).

In FIG. 6, as an example, a raster electron microscope image of a profile of a volumetric micro-dimensional structure from a sintered array of deposited silver nanoparticles on a glass substrate obtained by focusing and deposition of nanoparticles from an aerosol stream onto a moving substrate is presented. The volumetric microdimensional structure of silver nanoparticles has a bell-shaped cross-sectional shape, the width of the base and the height of the profile of which is controlled by the parameters of the process of focusing and deposition of nanoparticles from the aerosol stream.

When applying these technical solutions, in comparison with the method of manufacturing bulk structures from nanoparticles, where nanoparticles are used, the resistance to clogging of the nozzle is increased, uniform and smaller-scale bulk structures are achieved.

Thus, this technical solution will allow:

- improve the sanitary and hygienic conditions when creating products due to the lack of solvents and stabilizers;

- to make bulk microstructures from nanoparticles of proper quality with high chemical purity and possessing the necessary properties;

- reduce the cost of manufacturing bulk micro-sized structures from nanoparticles.

Information sources

1. US patent No. 10022789, IPC - B22D 23/00, 07/07/2018

2. US patent No. 10068863, IPC-B05D 5/12, 09.2018

3. US patent No. 9114409, IPC - B05B 7/00, 2015

Claims (8)

1. The method of additive manufacturing of bulk micro-sized structures from nanoparticles, including sintering of nanoparticles on a substrate, characterized in that an aerosol stream with nanoparticles in a pulse-periodic gas discharge in a transport gas stream is obtained, then the aerosol with nanoparticles is heated in a transport gas stream to obtain spherical nanoparticles of the required size, transport the resulting aerosol stream with nanoparticles to the head with a nozzle for focusing it on the substrate, served in the specified the nozzle has an aerosol stream with nanoparticles and at the same time a protective gas ensuring focusing of the aerosol stream of nanoparticles on the substrate and the nanoparticles are deposited from the focused aerosol stream on the substrate, while the deposition and sintering of nanoparticles on the substrate are carried out in a protective gas atmosphere, which is created under the nozzle. 2. The method according to p. 1, characterized in that it further optimizes the chemical composition of the nanoparticles by supplying reactive gas. 3. The method according to p. 1, characterized in that the sintering of the deposited nanoparticles on the substrate is carried out by a focused laser beam. 4. The method according to p. 3, characterized in that the focus of the focused laser beam is located at a distance L from the axis of the nozzle, where L = TV, where T is the formation time of the deposited nanoparticle array, V is the relative velocity of the substrate. 5. A device for the additive manufacturing of volumetric micro-sized structures from nanoparticles, comprising a substrate and a device for sintering deposited nanoparticles on a substrate, characterized in that it comprises a unit for receiving an aerosol stream with nanoparticles in a pulse-periodic gas discharge in communication with a transport gas source, a head with a nozzle for focusing an aerosol stream with nanoparticles on a substrate connected to a protective gas source, and a nanoparticle optimization unit in size and shape with a heating element, input One of which is in communication with the aerosol stream receiving unit with nanoparticles, and the output is with the nozzle of the head for focusing the aerosol stream with nanoparticles on the substrate, the substrate, the sintering device on the substrate of the deposited nanoparticles and the nozzle of the head for focusing the aerosol stream with nanoparticles on the substrate are placed deposition and sintering of nanoparticles on a substrate in a protective gas atmosphere. 6. The device according to p. 5, characterized in that the optimization unit is made with a second input in communication with the gas source. 7. The device of claim 5, wherein the sintering device on the substrate of the deposited nanoparticles is made in the form of a laser-optical device. 8. The device according to p. 7, characterized in that it is equipped with a coordinate table with which the substrate is attached, and the optical axis of the laser-optical device is placed in a plane passing through the axis of the nozzle.

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