3D printing apparatus and method of using the single-printhead achieved multi-material and multi-scale printing

Abstract

The present invention discloses a 3D printing apparatus and method of using a single-printhead to achieve multi-material and multi-scale printing. The apparatus comprises a base, a worktable, a wafer stage, a substrate, a power source, a printhead, and a support. The printhead is provided with a plurality of material inlets, each of which is connected to a different micro-feeding pump; and multiple materials are thoroughly mixed under the action of an agitator after being fed into the printhead, thereby achieving multi-material printing. In the present invention, a macroscopic geometrical shape of a printed object, microstructures in the interior and on the surface of the object are reasonably controlled, and integrated manufacturing of multi-scale structures is achieved.

Claims

1. A 3D printing apparatus for multi-material and multi-scale printing, comprising a base, a worktable, a wafer stage, a substrate, a power source, a printhead, and a support, wherein the printhead comprises a feed compartment, a mixing chamber disposed at a lower end of the feed compartment, and a conductive nozzle disposed at a lower end of the mixing chamber, a plurality of material inlets being formed in a sidewall of the feed compartment, and a mixing agitator for agitating a plurality of materials disposed in the mixing chamber; the base is mounted at the bottom, the support and the worktable being both disposed over the base, and the printhead being mounted on the support; the wafer stage is fixed on the worktable, and the substrate is disposed over the wafer stage and located below the printhead; a positive pole and a negative pole of the power source are connected to the conductive nozzle of the printhead and the wafer stage, respectively; and by means of relative motions between the worktable and the support, relative motions in x direction, y direction and z direction between the printhead and the substrate are achieved, and wherein the wafer stage is a vacuum chuck made of a metal material, and an air inlet of the vacuum chuck is connected to a vacuum pipe; the wafer stage fixes the substrate by means of vacuum negative pressure; and the wafer stage is also provided with an electric heating device comprising an electric heating rod or an electric heating sheet.

2. The 3D printing apparatus according to claim 1, wherein a waste liquid collector for leading a material out of the printhead is disposed in the mixing chamber, and the waste liquid collector comprises a waste liquid collecting pipe in which an integrated pump is built, and the waste liquid collecting pipe has one end disposed within the mixing chamber, and the other end communicating with the outside; and the printhead is provided with an air inlet that is connected to a pressure pipe.

3. The 3D printing apparatus according to claim 1, wherein the mixing agitator comprises a motor, a screw blade, and an end cap, the end cap covering an upper end of the feed compartment, the motor being mounted at a lower end of the end cap, and the screw blade being mounted within the mixing chamber at a lower end of the motor and connected to the motor by means of a transmission shaft.

4. The 3D printing apparatus according to claim 1, wherein the conductive nozzle is a metal nozzle or is coated with a conducting material, and has an inner diameter of 0.5-100 m.

5. The 3D printing apparatus according to claim 1, wherein the worktable is an x-y worktable; a z-direction worktable is mounted on the support, and the printhead is mounted on the z-direction worktable, and the substrate is fixed on the x-y worktable; and the printhead moves in z direction, while the substrate moves in x direction and y direction, such that the relative motions in x direction, y direction and z direction between the printhead and the substrate are achieved.

6. The 3D printing apparatus according to claim 1, wherein the x-y worktable is mounted at the lower end of the support, the z-direction worktable is mounted on the support, and the printhead is mounted on the z-direction worktable, such that motions of the printhead in z direction, y direction and z direction are achieved.

7. The 3D printing apparatus according to claim 1, further comprising a UV-curable light source that is disposed directly above the substrate and provides an exposure light source irradiating an area of a print material deposited on the substrate, wherein a camera or a visual detection module is disposed in the vicinity of the nozzle of the printhead.

8. An operating method of multi-material and multi-scale printing by using a 3D printing apparatus according to claim 2, comprising the following steps: fixing the substrate on the wafer stage, adjusting an operating distance between the nozzle and the substrate to a range of about 0.01-3 mm; feeding materials into the printhead; mixing materials by the mixing agitator; ejecting under the action of an intake pressure of the printhead and an electric field between the nozzle and the wafer stage a mixed solution from the nozzle for printing on the surface of the substrate; when a print material is required to be switched, starting the waste liquid collector to suck out the material residual in the printhead, and then filling with a new material to continue with printing; and when printing of a macrostructure or micron-scale structure or nano-scale structure of a different scale is needed, changing the distance between the nozzle and the substrate, and a voltage between the nozzle and the wafer stage for printing; and proceeding until the printing is completed.

9. The operating method according to claim 8, wherein the power source between the nozzle and the wafer stage has an output pulse voltage of 0.2-5 KV, an output pulse frequency of 10-1000 Hz, and a square output waveform; and the waste liquid collector has a vacuum pressure of 400 to 500 mbar.

10. The 3D printing apparatus of claim 7, wherein the exposure light source is used to cure a UV light sensitive material.

11. The 3D printing apparatus of claim 7, wherein the camera or the visual detection module is used for monitoring an actual electronic jet printing process and aligning patterns in the jet printing process.

12. The operating method according to claim 8, wherein said feeding materials into the printhead is achieved by micro-feeding pumps.

13. The operating method according to claim 8, wherein the intake pressure of the printhead is about 0.1-1 bar.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a structural schematic diagram of embodiment 1 of the present invention;

(2) FIG. 2 is a structural schematic diagram of a printhead in the present invention; and

(3) FIG. 3 is a structural schematic diagram of embodiment 2 of the present invention.

REFERENCE NUMERALS

(4) 1base, 2x-y worktable, 3wafter chuck, 4substrate, 5high-voltage power source, 6, print material, 7printhead, 8connecting bracket, 9mixing agitator, 10waste liquid collector, 11z-direction worktable, 12support, 13vacuum pipe, 14pressure pipe, 15feed compartment, 16material inlet, 17transmission shaft, 18mixing chamber, 19nozzle, 20end cover, 21stepping motor, and 22screw blade.

DETAILED DESCRIPTION OF THE EMBODIMENTS

(5) The present invention will be further described in conjunction with the accompanying drawings and the embodiments.

Embodiment 1

(6) FIG. 1 is a structural schematic diagram of an apparatus useful in multi-material and multi-scale 3D printing of the present invention. The apparatus useful in multi-material and multi-scale 3D printing comprises a base 1, an x-y worktable 2, a wafer stage 3, a substrate 4, a high-voltage power source 5, a print material 6, a printhead 7, a connecting bracket 8, a mixing agitator 9, a waste liquid collector 10, a z-direction worktable 11, a support 12, a vacuum pipe 13, and a pressure pipe 14, wherein the base 1 is disposed at the bottom, and the x-y worktable 2 is disposed on the base 1; the wafer stage 3 is fixed on the x-y worktable 2; the substrate 4 is fixed on the wafer stage 3; the printhead 7 is disposed directly above the substrate 4, and fixed on the connecting bracket 8; the connecting bracket 8 is fixed to the z-direction worktable 11; the z-direction worktable 11 is fixed on the support 12; the support 12 is fixed on the base 1; a mixing agitator 9 is disposed within the printhead 7, and an upper portion of the mixing agitator 9 is fixed to the upper surface of the printhead, and the lower portion of the mixing agitator 9 is placed in a mixing chamber 18 within the printhead 7; the lower portion of the waste liquid collector 10 is placed in the mixing chamber 18 of the printhead 7; an air inlet is formed in the upper portion of the waste liquid collector 10, and connected to the vacuum pipe 13; the wafer stage 3 is provided with an air inlet that is connected to the vacuum pipe 13; the printhead 7 is provided with an air inlet that is connected to the pressure pipe 14; the high-voltage power source 5 is disposed between a conductive nozzle 19 located at the bottommost portion of the nozzle 7 and the substrate 4, and wherein one side of the wafer stage 3 fixing the substrate 4 is connected to a negative pole, and the nozzle 19 is connected to the positive pole of the high-voltage power source 5.

(7) The x-y worktable 2 is a two-dimensional precision displacement table for achieving motions of the substrate 4 in x-y directions, the motions cooperating with the vertical motions of the printhead 7 in z direction to accomplish manufacturing of each layer of structure. An LS-180 linear displacement table is employed with an operating stroke of 150 mm and two-way repositioning accuracy of 0.1 micron.

(8) The wafer stage 3 is a vacuum chuck made of a metal material. The air inlet formed in the wafer stage 3 is connected with the vacuum pipe, and absorption and fixation of the substrate 4 are achieved by means of vacuum negative pressure. The wafer stage 3 is also provided with an electric heating sheet.

(9) The high-voltage power source 5 is a high-voltage pulse power source having an output pulse voltage continuously adjustable in a range of 0-4 KV, an output pulse frequency of 10-1000 Hz, and a square output waveform.

(10) The print materials 6 shown in this embodiment are four materials that are fed into the feed compartment 15 of the printhead 7 via the material inlets 16 formed in the printhead 7, respectively. The print materials 6 may be supplied to the feed compartment 15 of the printhead 7 by precise micro-injection pumps, respectively. The precise micro-injection pumps are connected to the material inlets by using teflon hoses.

(11) As shown in FIG. 2, the printhead 7 comprises three portions: the feed compartment 15 as an upper portion, the mixing chamber 18 as a middle portion, and the conductive nozzle 19 as a lower portion, wherein the feed compartment 15 is uniformly provided with four material inlets 16, and materials enter into the feed compartment 15 of the printhead 7 via the material inlets 16, respectively. A screw blade 22 of the mixing agitator 9 disposed in the middle mixing chamber 18 is used for thoroughly agitating and evenly mixing the print materials 6 from different material inlets 16. The nozzle 19 at the bottommost portion of the printhead 7 is the conductive nozzle. A hollow stainless steel nozzle having an inner diameter of 0.5 micron is used in this embodiment.

(12) The mixing agitator 9 comprises an end cap 20, a stepping motor 21, and a screw blade 22, wherein the screw blade 22 is connected to the stepping motor 21 by means of a transmission shaft 17; the stepping motor 21 is fixed to the lower end face of the end cap 20; and the end cap 20 is fixed to the upper end of the feed compartment 15 of the printhead 7.

(13) The waste liquid collector 10 is used for recovering a material residual in the printhead 7 by means of vacuum negative pressure. For material switching, the waste liquid collector 10 is started to recover the print materials 6 residual in the printhead 7 thereto. An integrated pump is built in the waste liquid collector. The vacuum pressure in the collector is 500 mbar.

(14) The printhead 7, the mixing agitator 9 and the waste liquid collector 10 form an intelligent and active mixing multi-material printing printhead system that achieves the functions of supply of multiple materials, even mixing of the multiple materials, waste recovery, and the like, as shown in FIG. 2.

(15) The z-direction worktable 11 is an M-501 ultra-precise z-axis displacement table from PI company, which has a repeatability precision of 0.1 micron. The operating distance between the nozzle 19 at the bottom of the printhead 7 and the substrate 4 is 200 microns.

(16) The operating range of the pressure pipe is 0-1 bar; and the operating range of the vacuum pipe is below 0.2 bar.

(17) A high-speed camera or a visual detection module may be disposed in the vicinity of the nozzle for monitoring an actual electronic jet printing process and aligning patterns in the jet printing process. The apparatus may comprise a UV-curable light source that is disposed directly above the substrate to achieve curing of a UV light-sensitive material.

Embodiment 2

(18) As shown in FIG. 3, which is a structural schematic diagram of an apparatus useful in multi-material and multi-scale 3D printing of the present invention, the apparatus comprises a base 1, an x-y worktable 2, a wafer stage 3, a substrate 4, a high-voltage power source 5, a print material 6, a printhead 7, a connecting bracket 8, a mixing agitator 9, a waste liquid collector 10, a z-direction worktable 11, a support 12, a vacuum pipe 13, and a pressure pipe 14, wherein the base 1 is disposed at the bottom, and the x-y worktable 2 is disposed on the base 1; the wafer stage 3 is fixed on the base 1; the substrate 4 is fixed on the wafer stage 3; the printhead 7 is disposed directly above the substrate 4, and fixed on the connecting bracket 8; the connecting bracket 8 is fixed to the z-direction worktable 11; the z-direction worktable 11 is fixed on the support 12; and the support 12 is fixed on the x-y worktable 2 that is fixed on the base 1.

(19) The x-y worktable 2 is a two-dimensional precision displacement table for achieving motions of the support 12 in x-y directions, and the printhead 7 moves up and down in z direction to accomplish manufacturing of each layer of structure. An LS-180 linear displacement table is employed with an operating stroke of 150 mm and two-way repositioning accuracy of 0.1 micron.

(20) While the specific embodiments of the present invention are described above in conjunction with the accompanying drawings, they are not intended to limit the protection range of the present invention. Those skilled in the art will understood that various modifications or variations that may be made by those skilled in the art on the basis of the technical solutions of the present invention without creative effort are still within the protection scope of the present invention.