Device and Method for Producing Microstructures

Abstract

A device for producing microstructures, particularly microneedles and more particularly microneedle arrays, including a female mold that has, on a top side, at least one in particular conical depressed portion for producing a microstructure. The female mold is, for example, in the form of a silicone cap and is connected to a hollow cylinder in particular via a holding element. A plunger is disposed movably inside the hollow cylinder.

Claims

1. Device for producing microstructures, comprising a female mold comprising at least one preferably conical cavity at the upper side for producing a microstructure, a base element comprising a hollow cylinder, a holding element, which is connected to the female mold, for holding the female mold at the hollow cylinder such that the female mold spans an opening of the hollow cylinder, and a plunger arranged in the hollow cylinder and displaceable in the longitudinal direction of the hollow cylinder.

2. Device according to claim 1, wherein the holding element comprises an elongatable, elastic intermediate element or is connected to an intermediate element.

3. Device according to claim 1, wherein the holding element comprises or is connected to a connecting element for a positive connection to the hollow cylinder.

4. Device according to claim 3, wherein the intermediate element is connected to the connecting element and the female mold.

5. Device according to claim 1, wherein the holding element surrounds the hollow cylinder.

6. Device according to claim 1, wherein the holding element rests on an inner side of the hollow cylinder completely in the circumferential direction.

7. Device according to claim 3, wherein a gap is formed between the connecting element and the hollow cylinder.

8. Device according to claim 1, wherein the plunger has a planar upper side which, in an inserted position, rests on a lower side of the female mold.

9. Device according to claim 1, wherein the base element comprises a plurality of hollow cylinders.

10. Device according to claim 1, wherein a plurality of plungers is provided, which plungers are connected to one another via a connecting plate.

11. Method for producing microstructures with a device according to claim 1, the method comprising the steps of: inserting the at least one plunger into at least one hollow cylinder respectively, so that an upper side of the at least one plunger rests on a lower side of the female mold, filling the at least one cavity of the female mold with a formulation, retracting the plunger, and removing a microstructure after the curing thereof.

12. Method according to claim 11, wherein the at least one plunger is inserted such that the intermediate element is elongated and the female mold is lifted off from an edge surrounding the opening of the hollow cylinder.

13. Method according to claim 11, wherein, when the at least one plunger is retracted, the intermediate element shortens or contracts, so that the lower side of the female mold rests on the edge of the hollow cylinder surrounding the opening.

14. Method according to claim 11, wherein, if a plurality of female molds is present, these are, either individually one after the other, all together or in groups, lifted off by the at least one plunger and filled subsequently.

15. Method according to claim 11, wherein the at least one female mold is filled with a formulation via a dosing means.

16. The Device according to claim 4, wherein the intermediate element, the connecting element, and the female mold are formed in one piece therewith.

17. The Device according to claim 9, wherein the plurality of hollow cylinders are connected to one another.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In the Figures:

[0029] FIG. 1 shows a schematic sectional view of a first preferred embodiment of the device,

[0030] FIG. 2 shows a schematic sectional view of a second preferred embodiment of the device, and

[0031] FIGS. 3 and 4 show schematic perspective views of another embodiment of the device according to the disclosure, in which a plurality of individual devices shown in FIG. 1 or 2 is combined.

DETAILED DESCRIPTION

[0032] The first preferred embodiment of the disclosure schematically illustrated in FIG. 1 comprises a cap 10 made in particular of a silicon material, which is formed rotationally symmetrically with respect to e center line 12. The cap 10 is arranged on a hollow cylinder 14 which is connected to a basic element 16. In the embodiment illustrated, the hollow cylinder 14 circular cylindrical in shape and rotationally symmetric with respect to the longitudinal axis 12.

[0033] A plunger 18 is arranged in the hollow cylinder 14 for displacement in the direction of the arrow 20. The plunger 18 is circular cylindrical and also rotationally symmetric with respect to the longitudinal axis.

[0034] In the embodiment illustrated, the cap 10 is formed integrally and comprises a female mold 22, on the upper side 24 of which in particular a plurality of preferably frustoconical cavities is provided. This makes it possible to produce a microneedle array by filling it with a formulation. In the embodiment illustrated, the female mold 22 is surrounded by an annular reinforcing element 26 reinforcing the edge of the female mold. The same is connected to a circular intermediate element 28 by which a connection to a holding element 30 is made. In the embodiment illustrated, the holding element 30 is connected to an outer side 36 of the hollow cylinder 14 using positive connecting elements 32, 34. The connecting elements are formed as, for example, an annular bead 32 provided on the outer side of the hollow cylinder 14 and cooperates with a corresponding annular recess 34 in the manner of a snap-in connection.

[0035] Since, in the embodiment illustrated, the entire cap 10 is made of a silicone material and the intermediate element 28 has a smaller wall thickness, the intermediate element 28 is an elongatable, in particular elastic intermediate element. A gap 48 is formed between the intermediate element 28 and the hollow cylinder 14.

[0036] By displacing the plunger 18 upward in FIG. 1, a planar upper side 38 of the plunger comes to rest on an inner side 40 of the female mold 22. Thereby, the female mold 22 is lifted off an edge 42 of the hollow cylinder which surrounds an opening 44 of the hollow cylinder.

[0037] In an alternative embodiment, the inner side of the female mold 22 does not rest on the edge 42 of the hollow cylinder. Nevertheless, the tolerance chain is broken by lifting the female mold 22 by the plunger 18, so that only the tolerance of the thickness of the female mold 22 is relevant and the tolerances of the hollow cylinder 14 no longer have to be considered or adversely affect the quality of the microstructure to be produced.

[0038] In this lifted-off state of the female mold 22 a formulation can be applied onto the upper side of the female mold, in particular by spraying, so that the sprayed material penetrates into the cavities. Thereafter, the plunger 18 is retracted so that the inner side 40 of the female mold 22 rests on the edge 42 of the hollow cylinder 14 again and can be cured in this position.

[0039] In the alternative embodiment illustrated in FIG. 2, similar or identical components are identified by the same reference numerals.

[0040] The essential difference between the two embodiments illustrated in FIGS. 1 and 2 is that the silicone cap 10 of the embodiment illustrated in FIG. 1 surrounds the hollow cylinder 14 or can be slipped onto the same, while it is arranged in the hollow cylinder 14 in FIG. 2. In this respect, in particular the holding element 30 of the cap, as well as the connecting elements 32, 34 are arranged in the hollow cylinder 14. In this embodiment, the female mold 22 does not rest on an edge of the hollow cylinder 14. For the rest, the function is identical.

[0041] FIGS. 3 and 4 show perspective schematic views of a field or array of a plurality of devices that can be seen in FIG. 1 or 2. Here, a plurality of hollow cylinders 14 is connected via the base element 16. A corresponding number of plungers 18 in the illustrated embodiment is connected to one another via an in particular plate-shaped connecting element 26. Instead of the field comprising 3×3 hollow cylinders and plungers schematically illustrated in FIGS. 3 and 4, a significantly larger array of, for example, 10×10, 15×15, 20×20 hollow cylinders and plungers can be provided.

[0042] Instead of providing a field with a corresponding number of plungers 18, it is also possible to provide a group of, for example, 4, 8 or 16 plungers, so that some of the female molds are lifted by the plungers, respectively, are filled with material, and the plungers are then retracted again. Thereafter, the field of female molds and/or the group of plungers is displaced.