Methods and devices for micro-dosing a liquid are disclosed herein. According to one embodiment, a method for a time controlled micro-dosing of a liquid from a liquid reservoir includes: receiving the liquid reservoir with a structure wherein the structure is portable; securing the liquid reservoir to the structure; connecting a second end of a drive unit to a piston disposed within the liquid reservoir; activating a drive motor; displacing the drive unit with respect to the structure towards the piston in an axial direction with the drive motor; moving the piston axially within the liquid reservoir; and micro-dosing the liquid from the liquid reservoir.