3D PRINTING DEVICE, 3D PRINTING METHOD AND 3D TUBULAR OBJECTS OBTAINED BY SAID METHOD

Abstract

A 3D printing method for manufacturing a 3D tubular object includes creating successive layers of polymerized resin. Each layer is created by providing, on an external surface of a build platform, a fluid resin which is polymerizable by electromagnetic radiation. A beam of electromagnetic radiation suitable for polymerizing the fluid resin is positioned, according to a printing model, towards the external surface of the build platform, creating the layer of polymerized resin. The build platform includes a stem having a longitudinal axis, and forming a tubular shaped surface around the longitudinal axis, so that the external surface of the build platform is included in the tubular shaped surface. The beam is variably positioned according to the printing model to impinge on different points of the fluid resin. The 3D tubular object is obtained by removing from the stem a 3D object formed by the successive layers of polymerized resin.

Claims

1. A 3D printing method, for manufacturing a 3D tubular object according to a printing model, starting from a build platform having an external surface; said method comprising creating one or more successive layers of polymerized resin, in which each layer of polymerized resin is created by the following steps: providing, on said external surface of said build platform, a fluid resin which is polymerizable by electromagnetic radiation; according to said printing model, positioning a beam of an electromagnetic radiation suitable for polymerizing said fluid resin towards said external surface of said build platform, thereby creating said layer of polymerized resin; wherein said build platform comprises a stem having a longitudinal axis, said stem forming a tubular shaped surface around said longitudinal axis, so that said external surface of said build platform is comprised in said tubular shaped surface, and wherein said beam is variably positioned according to said printing model so that it impinges on different points of said fluid resin on at least one part of said tubular shaped surface; and said 3D tubular object is obtained by removing from said stem a 3D object formed on said tubular shaped surface by said one or more successive layers of polymerized resin.

2. The 3D printing method according to claim 1, wherein the step of positioning said beam towards said tubular shaped surface of said stem according to said printing model, comprises positioning said beam by, at least: a circumferential positioning in a circumferential direction around said longitudinal axis; a longitudinal positioning along a longitudinal direction defined by said longitudinal axis; and preferably, a distance positioning between said source output and said tubular shaped surface of said stem, thereby defining a beam length.

3. The 3D printing method according to claim 1, wherein it comprises the additional steps of creating one or more successive additional layers of polymerized resin, wherein each additional layer is created by the following steps: providing an additional fluid resin on said tubular shaped surface of said stem, said additional fluid resin being polymerizable by electromagnetic radiation; according to said printing model, variably positioning a beam of an electromagnetic radiation suitable for polymerizing said additional fluid resin towards said tubular shaped surface of said stem so that it impinges on different points of said fluid resin on at least one part of said tubular shaped surface of said stem having a tubular shape, thereby creating said layer of polymerized resin.

4. The 3D printing method according to claim 1, wherein said fluid resin is biocompatible and said 3D tubular object manufactured by said method is a stent.

5. The 3D tubular object manufactured by the method according to claim 1, said 3D tubular object being a 3D object having an empty internal area delimited by a tubular surface and polymerized resin extending over the whole or part of said tubular surface.

6. The 3D tubular object according to claim 5, comprising a single layer of polymerized resin.

7. The 3D tubular object according to claim 5, comprising successive concentric layers of polymerized resin.

8. The 3D tubular object according to claim 7, wherein said concentric layers are made from different resins.

9. The 3D tubular object according to claim 5, wherein said polymerized resin is biocompatible and said 3D tubular object is a stent.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0082] Further advantages and features of the invention will become apparent from the following description, in which, without any limiting character, preferred embodiments of the invention are disclosed, in reference to the accompanying figures:

[0083] FIG. 1 is a perspective view of an embodiment of a 3D printing device according to the invention.

[0084] FIG. 2 is a front view of the same embodiment of the 3D printing device shown in FIG. 1.

[0085] FIG. 3 is a detailed front view of a 3D printing device according to one embodiment of the invention, showing the part corresponding to the electromagnetic radiation source, the beam, the stem, and the resin tank. The resin tank is shown sectioned in order to display the stem. Sections have been marked with parallel diagonal lines in the figures.

[0086] FIG. 4A is a detailed perspective view of a stem of a 3D printing device according to one embodiment of the invention that has been used to manufacture a 3D tubular object, in particular a stent, that is still attached to the stem.

[0087] FIG. 4B is the equivalent view of 4A but in a different embodiment wherein the stem is made of a solid block instead of a core and an external layer.

[0088] FIG. 5 is a perspective view of the stent of FIG. 8 once it has been removed from the stem of the 3D printing device.

[0089] FIG. 6 is a detailed front view of a 3D printing device according to another embodiment of the invention.

[0090] FIG. 7 is a detailed front view of the tank and stem of a 3D printing device according to another embodiment of the invention.

[0091] FIG. 8 is a detailed front view of a 3D printing device according to one embodiment of the invention having a laser profiler to measure the thickness of the layer of fluid resin over the tubular shaped surface of the stem.

[0092] FIG. 9 is a front view of a 3D printing device according to another embodiment of the invention.

[0093] FIG. 10 is a front view of a 3D printing device according to another embodiment of the invention.

DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION

[0094] Some of the embodiments shown in the figures have been made using as a basis a well-known stereolithography 3D printer, in particular the PRUSA MK2S, adapted only for experimental essays in the laboratory that have rendered very positive results. Those skilled in the art will clearly identify the modifications required for the invention. Future versions aimed for the market would use a different structure that the skilled person would have no problems in designing using the teachings of this document.

[0095] FIGS. 1, 2, 3 and 4 show one first exemplary embodiment of a 3D printing device 1 of the invention. Said 3D printing device 1 is aimed for manufacturing at least one 3D tubular object 100 according to a printing model, and it has a build platform having an external surface 2. For this first embodiment, said build platform is a stem 3 having a longitudinal axis 9 as shown in FIG. 3. The stem 3 forms a tubular shaped surface 2 around the longitudinal axis 9. Therefore, the external surface of the build platform is the tubular shaped surface 2 of the stem 3 and has a tubular shape around the longitudinal axis 9. As shown in the figures, the tubular shaped surface 2 of the stem 3 has symmetry of revolution regarding the longitudinal axis 9. In particular, the stem 2 is a cylinder, and the tubular shaped surface 2 has a cylindrical shape.

[0096] The 3D printing device 1 also has resin providing means that is configured for providing, on the tubular shaped surface 2 of the stem 3, a fluid resin 4 which is polymerizable by electromagnetic radiation. In particular, said resin providing means has a resin tank 12, arranged in such a way that said stem 3 goes through said resin tank 12. As shown in FIG. 3, the stem 3 is arranged horizontally so that all said tubular shaped surface 2 is located below a resin filling level 13 in said resin tank 12.

[0097] The 3D printing device 1 is provided with an electromagnetic radiation source 5 that is configured to emit, from a source output 6 to the tubular shaped surface 2 of the stem, a beam 7 of an electromagnetic radiation suitable for polymerizing the fluid resin 4. For the first embodiment, said electromagnetic radiation source 5 is a laser 19 having a laser output, so that said source output 6 is said laser output. The laser beam 7 has been represented with a dashed line in the figures.

[0098] In order to position the beam 7, the 3D printing device is also provided with beam positioning means 8 that is arranged to variably positioning an impinging point of said beam 7 so that the beam 7 impinges on different points of at least one part of the fluid resin 4 provided on said tubular shaped surface 2. Further, the 3D printing device 1 has control means that is used for controlling the beam positioning means 8 and the electromagnetic radiation source 5 according to the printing model, in order to manufacture the 3D tubular object 100. For the sake of clarity, control means is not shown in the figures. FIG. 1 and FIG. 2 show that the beam positioning means 8 is configured to variably position an impinging point of the beam 7 on said fluid resin 4 using three kinds of positioning elements corresponding to three coordinates. Firstly, a circumferential positioning in a circumferential direction around the longitudinal axis 9. Said circumferential positioning is performed by a rotation control element 20, in particular a servomotor operationally connected to the stem 3 driving the rotation of said stem 3 around the longitudinal axis 9. Secondly, a longitudinal positioning along a longitudinal direction defined by said longitudinal axis 9. The longitudinal positioning is performed by a longitudinal position control element 21 having two parallel straight longitudinal guides 211 configured to longitudinally position the laser 19 that is slidable mounted thereto and, accordingly, position the source output 6. A longitudinal traction belt 212 is used to cause the laser 19 to slide longitudinally along said longitudinal guides 211. The longitudinal guides 211 are parallel to the stem 3 and the longitudinal axis 9, and the source output 6 is arranged for emitting the beam 7 in a downward vertical direction that is perpendicular to the longitudinal axis 9. Thirdly, a distance positioning between the source output 6 and the tubular shaped surface 2 of the stem 3, by means of a distance control element 22, thereby allowing to determine the length of the beam 7. Said distance control element 22 has four straight transversal vertical guides 221 configured to transversally position the source output 6 in a direction orthogonal to the longitudinal axis 9. In the first embodiment, said vertical guides 221 are arranged vertically in order to vertically position the source output 6. In particular, the vertical guides 221 are arranged two by two at both longitudinal ends of the longitudinal guides 211 that are slidably mounted thereto. In this way, the longitudinal guides 211 can slide up and down along the vertical guides 221 and vertically position the source output 6.

[0099] The 3D printing device 1 of the first embodiment is further provided with temperature control means. For the sake of clarity, said temperature control means is not shown in the figures, but has a Peltier cell arranged in the tank, so that it is possible to control the temperature of the fluid resin 4.

[0100] For the first embodiment, the laser 19 emits a beam 7 of ultraviolet radiation, UV. Therefore, the 3D printing device 1 is able to be used with UV-polymerizable resins. In particular, it is possible to use prolycaprolactone-derived resins, for example, PCL-diacrilate. Nevertheless, other types of electromagnetic radiation and fluid resins 4 can also be envisaged within the scope of the invention, for example, in the case that the laser 19 emits a beam 7 of infrared radiation or visible light. Biocompatible resins 4, possibly having a therapeutic additive, can also be used with the 3D printing device of the invention.

[0101] Using the 3D printing device 1 of the embodiments described in this document, the 3D printing method for printing a 3D tubular object can comprise several steps for creating successive layers of polymerized resin. Each layer is created by providing a fluid resin 4, so different fluid resins 4 can be envisaged to be used for different layers.

[0102] FIG. 4A is a detailed view of the stem 3 of the first embodiment. In this case, the stem 3 has a steel rigid core 10 wrapped in an external layer 11 made of nylon forming the tubular shaped surface 2 of the stem 3. Other metals can be envisaged for the core 10, for example titanium. In addition, other elastomer materials can also be envisaged for the external layer 11, for example, latex. FIG. 4A shows a 3D tubular object that has been manufactured with the 3D printing device 1 following the 3D printing method of the invention, and that is still attached to the tubular shaped surface 2. FIG. 5 shows the same 3D tubular object once removed from the stem 3. In the case of the FIG. 4 and FIG. 5, the invention has been used in order to manufacture a 3D printed stent. FIG. 4B shows a different embodiment of a stem 3 made of a solid block, instead of a core and an external layer, and wherein the tubular shaped surface 2 is not made of a different material than the rest of the stem 3.

[0103] As for the first embodiment, the tubular shaped surface 2 of the stem 3 is a diffuse surface that does not reflect the wavelengths of said electromagnetic radiation. The tubular shaped surface 2 of the stem 3 is opaque to the wavelengths.

[0104] Other embodiments of the 3D printing device according to the invention are disclosed hereinafter. These embodiments share most of the features disclosed in the first embodiment above. Therefore, only the differentiating features will be described in detail. For the sake of brevity, common features shared with the first embodiment disclosed above will not be described again hereinbelow.

[0105] FIG. 6 shows a second embodiment of the 3D printing device 1 according to the invention, wherein the electromagnetic radiation source 5 has an electromagnetic radiation generator 16 and an optical fiber guidance module 17 that guides the electromagnetic radiation to an optical fiber output, so that said source output 6 is said optical fiber output.

[0106] FIG. 7 shows a third embodiment of the 3D printing device 1, wherein the stem 3 is arranged horizontally. In this third embodiment a part of the tubular shaped surface 2 is located above a resin filling level 13 in the resin tank 12 and another part of the tubular shaped surface 2 is located below said resin filling level 13.

[0107] FIG. 8 shows a fourth embodiment of the 3D printing device 1, wherein the stem 3 is arranged horizontally and the tubular shaped surface 2 is located below a resin filling level 13 in the resin tank 12. In this embodiment, the 3D printing device 1 further comprises layer measuring means 40, configured to determine a measure of thickness of a layer of said fluid resin 4 that is provided on said tubular shaped surface 2. Said layer measuring means 40 comprises a laser profiler, so that said measure of thickness is determined from the difference between a measure of said laser profiler when no fluid resin 4 is provided on said tubular shaped surface 2 and a measure when said fluid resin 4 is provided on said tubular shaped surface 2. In addition, the device further comprises layer thickness control means, which is configured to receive said measure of thickness and, when necessary, changing the thickness of the layer of resin provided on said tubular shaped surface 2, in this case by means of changing the amount of fluid resin 4 provided by said resin providing means, that is, the amount of fluid resin 4 provided in the resin tank 12. Other embodiments can be envisaged, for example, starting from the third embodiment of FIG. 7 and where the layer thickness control means is configured to change the thickness by means of changing the temperature of said fluid resin 4 and/or changing the rotation speed of said stem 3.

[0108] FIG. 9 shows a fifth embodiment of the 3D printing device 1, wherein the stem 3 is arranged vertically, the source output 6 is arranged to emit the beam 7 in a horizontal direction, and the distance control element 22 is configured to horizontally position the source output 6. In this fifth embodiment the resin tank 12 has a container 14 arranged around the stem 3, so that a resin chamber 15 is defined between said container 14 and the tubular shaped surface 2 of the stem 3. In this fifth embodiment, the container 14 is made of a material which is transparent to the electromagnetic radiation emitted by the laser 19.

[0109] FIG. 10 shows a sixth embodiment of the 3D printing device 1, wherein the stem 3 is arranged vertically and wherein the source output 6 is arranged to emit the beam 7 in a horizontal direction. In this sixth embodiment the resin tank 12 has a container 14 arranged around the stem 3, so that a resin chamber 15 is defined between said container 14 and the tubular shaped surface 2 of the stem 3. The container 14 is made of a material which is transparent to the electromagnetic radiation emitted by the laser 19. Contrary to the previous examples, this sixth embodiment is not provided with a distance control element 22. In addition, there is no rotational control element 20 affecting the stem 3 but a source rotation element 30 affecting the laser 19, so that, the source output 6 is moved around the stem 3, in particular, around the longitudinal axis 9. As shown in FIG. 9, the source rotation element 30 comprises a rotatory structure, rotatably mounted around the longitudinal axis 9 that, in this case, is arranged vertically. The longitudinal control element 21 is fixed to said rotatory structure, so that, when the rotatory structure rotates, it causes beam 7 to be positioned in the circular direction.

[0110] In other possible embodiments not shown in the figures, the tubular shaped surface 2 of the stem 3 has symmetry of revolution regarding said longitudinal axis 9, so that the tubular shaped surface 2 has a shape that is conical or frustoconical.