A drug delivery device includes a housing component having an interior space and an exterior surface, an injection needle having a retracted state wherein the needle is hosted inside of the interior space and a deployed state wherein a pointed end of the needle projects beyond the exterior surface of the housing component, a needle drive mechanism coupled to the needle to move the needle between the retracted and deployed states, and a drug container disposed within the interior space. The drug container is pre-filled with sterile liquid drug and to be in fluid communication with the needle. The sterile liquid drug herein might be solution, suspension, emulation or other forms in fluid state. The drug delivery device also includes a microcontroller coupled to the needle drive mechanism. The microcontroller is configured to control the needle drive mechanism to move the needle between the retracted state and the deployed state. Further, the delivery device is wearable, disposable, and single-use.