An insertion/retraction mechanism for a drug delivery device, the insertion/retraction mechanism comprising: a retraction hub comprising an inside surface, a first primary rotational stop extending radially inwardly from the inside surface, and a second primary rotational stop extending radially inwardly from the inside surface; an insertion hub disposed inside of the retraction hub comprising a shaft having an outside surface, a first complementary rotational stop extending radially outwardly from the outside surface, and a second complementary rotational stop extending radially outwardly from the outside surface, the insertion hub further comprising a spindle connected to the shaft, the spindle having a needle pathway; an insertion/retraction mechanism housing that houses the retraction hub and the insertion hub in a rotatable manner and comprises a needle exit aperture; a flexible needle configured to extend through the needle pathway of the spindle of the insertion hub and to selectively pass through the needle exit aperture of the insertion/retraction mechanism housing during insertion and retraction of the flexible needle; a dual torsion spring system, the dual torsion spring system including a right wound torsion spring and a left wound torsion spring, operably connected to the retraction hub, the insertion hub, and the insertion/retraction mechanism housing; and an activation trigger operably connected to the dual torsion spring system; wherein, in an initial position, the first primary rotational stop engages the first complementary rotational stop, the retraction hub is in a first rotational position relative to the insertion/retraction mechanism housing, and the flexible needle does not pass through the needle exit aperture, wherein, in an inserted position, the second primary rotational stop engages the second complementary rotational stop as a result of the insertion hub being rotated relative to the retraction hub by a first spring bias provided by the dual torsion spring system, the retraction hub is in the first rotational position relative to the insertion/retraction mechanism housing, and the flexible needle passes through the needle exit aperture, and wherein, in a retracted position, the second primary rotational stop engages the second complementary rotational stop, the retraction hub is in a second rotational position relative to the insertion/retraction mechanism housing as a result of the retraction hub being rotated relative to the insertion/retraction mechanism housing by a second spring bias provided by the dual torsion spring system, and the flexible needle does not pass through the needle exit aperture. a retraction hub comprising an inside surface, a first primary rotational stop extending radially inwardly from the inside surface, and a second primary rotational stop extending radially inwardly from the inside surface; an insertion hub disposed inside of the retraction hub comprising a shaft having an outside surface, a first complementary rotational stop extending radially outwardly from the outside surface, and a second complementary rotational stop extending radially outwardly from the outside surface, the insertion hub further comprising a spindle connected to the shaft, the spindle having a needle pathway; an insertion/retraction mechanism housing that houses the retraction hub and the insertion hub in a rotatable manner and comprises a needle exit aperture; a flexible needle configured to extend through the needle pathway of the spindle of the insertion hub and to selectively pass through the needle exit aperture of the insertion/retraction mechanism housing during insertion and retraction of the flexible needle; a dual torsion spring system, the dual torsion spring system including a right wound torsion spring and a left wound torsion spring, operably connected to the retraction hub, the insertion hub, and the insertion/retraction mechanism housing; and an activation trigger operably connected to the dual torsion spring system; wherein, in an initial position, the first primary rotational stop engages the first complementary rotational stop, the retraction hub is in a first rotational position relative to the insertion/retraction mechanism housing, and the flexible needle does not pass through the needle exit aperture, wherein, in an inserted position, the second primary rotational stop engages the second complementary rotational stop as a result of the insertion hub being rotated relative to the retraction hub by a first spring bias provided by the dual torsion spring system, the retraction hub is in the first rotational position relative to the insertion/retraction mechanism housing, and the flexible needle passes through the needle exit aperture, and wherein, in a retracted position, the second primary rotational stop engages the second complementary rotational stop, the retraction hub is in a second rotational position relative to the insertion/retraction mechanism housing as a result of the retraction hub being rotated relative to the insertion/retraction mechanism housing by a second spring bias provided by the dual torsion spring system, and the flexible needle does not pass through the needle exit aperture.