Force-controlled applicator for applying a microneedle device to skin

1. An applicator for applying a microneedle device to a skin surface, the applicator comprising:

a microneedle device having a first side comprising a microneedle array and a second side opposite the first side, the first side configured to be positioned toward the skin surface;

a housing having a first surface configured to be positioned toward the skin surface; and

a connecting member positioned to couple the microneedle device to the housing and configured to allow the microneedle device to move relative to the housing between

a first position in which at least a portion of the microneedle device extends beyond the first surface of the housing, and

a second position in which the microneedle device is recessed within the housing, such that the microneedle device does not extend beyond the first surface of the housing,

wherein the connecting member is configured to move the microneedle device to the second position when a threshold application force is applied to the first side of the microneedle device in a direction substantially perpendicular with respect to the microneedle device, and wherein the first surface of the housing is not in contact with the skin surface when the microneedle device is in the first position.

2. The applicator of claim 1 , wherein the applicator is configured to be pressed in a direction substantially perpendicular to the microneedle device when the microneedle device is in the first position to press the microneedle device into the skin surface until the threshold application force is reached and the microneedle device is moved from the first position to the second position.

3. A method of applying a microneedle device to a skin surface, the method comprising:

providing the applicator of claim 1 ;

pressing the applicator in a direction substantially perpendicular to the microneedle device into the skin surface when the microneedle device is in the first position until the threshold application force is met or exceeded; and

moving the microneedle device to the second position in response to meeting or exceeding the threshold application force.

4. The applicator of claim 1 , wherein the connecting member has

a first equilibrium position in which the microneedle device is in the first position, and

a second equilibrium position in which the microneedle device is in the second position; and

wherein the connecting member is configured to move to the second equilibrium position when the threshold application force is met or exceeded.

5. The applicator of claim 1 , wherein the connecting member is coupled to the housing via a first hinge, and wherein the connecting member is coupled to the microneedle device via a second hinge.

6. The applicator of claim 1 , wherein a first portion of the connecting member is coupled to the housing via a first hinge, and a second portion of the connecting member is coupled to the microneedle device via a second hinge.

7. The applicator of claim 5 , wherein the connecting member pivots about the first hinge and the second hinge when the microneedle device is moved between the first position and the second position.

8. The applicator claim 5 , wherein the first hinge and the second hinge are living hinges.

9. The applicator of claim 1 , wherein the connecting member comprises a bifurcating spring.

10. The applicator of claim 1 , wherein the threshold application force is a first threshold application force, and wherein the connecting member is configured to move the microneedle device to the first position when a second threshold application force is applied to the second side of the microneedle device in a direction oriented substantially perpendicularly with respect to the microneedle device.

11. The applicator of claim 10 , wherein the second threshold application force is equal and opposite to the first threshold application force.

12. The applicator of claim 1 , wherein the connecting member is further configured to move the microneedle device to the first position when the threshold application force is applied to the second side of the microneedle device in a direction oriented substantially perpendicularly with respect to the microneedle device.

13. The applicator of claim 1 , further comprising a plunger movable with respect to the housing between a first position and a second position to move the microneedle device to the first position.

14. The applicator of claim 13 , wherein the microneedle device is configured to move from its first position to its second position in a first direction, and wherein the plunger is configured to move from its first position to its second position in a second direction that is opposite the first direction and oriented substantially perpendicularly with respect to the microneedle device.

15. The method of claim 3 , further comprising moving the microneedle device from the second position to the first position.

16. The method of claim 3 , further comprising returning the microneedle device to the first position.

17. The method of claim 16 , wherein the applicator further comprises a plunger movable with respect to the housing between a first position and a second position, and wherein returning the microneedle device to the first position includes moving the plunger from its first position to its second position.

18. The method of claim 16 , wherein moving the microneedle device from the first position to the second position includes moving the microneedle device in a first direction oriented substantially perpendicularly with respect to the microneedle device, and wherein returning the microneedle device to the first position includes moving the microneedle device in a second direction that is opposite the first direction.

19. The method of claim 16 , wherein the threshold application force is a first threshold application force, and wherein returning the microneedle device to the first position includes applying a second threshold application force to the second side of the microneedle device.

20. The method of claim 19 , wherein the second threshold application force is equal and opposite to the first threshold application force.