Microneedle arrays, methods for fabricating microneedle arrays, medical devices, and methods for operating medical devices are provided. A method for fabricating a microneedle array includes providing a sheet blank of material. Further, the method includes stamping the sheet blank of material with a progression of dies, wherein the material is displaced into the microneedle array. A medical device includes a microneedle array, a base member having a first surface supporting the microneedle array and a second surface, and a flexible wall enclosing a chamber between the flexible wall and the second surface of the base member. The flexible wall is biased toward an extended configuration enclosing a first volume in the chamber. Further, the flexible wall is movable to a depressed configuration enclosing a second volume in the chamber less than the first volume.