Piercing device for an administration device

A piercing device for an administration device, the piercing device comprising:

• a first biased elastic element applying a first biasing force for generating a piercing movement in a piercing direction;
• a second biased elastic element applying a second biasing force for generating a movement counter to the piercing direction;
• a base;
• a cannula unit comprising a first cannula and a second cannula, wherein the cannula unit is movable relative to the base from a secured position in the piercing direction, wherein the cannula unit is biased in the piercing direction by the first biased elastic element, and wherein the second cannula is biased counter to the piercing direction by the second biased elastic element;
• a securing element configured to hold the biased cannula unit in the secured position, wherein the securing element comprises a thermosensitive area configured to be deformable when heated under mechanical tension, and wherein the securing element is biased by the first biased elastic element;
• and
• a heating element configured to heat the thermosensitive area of the securing element such that the thermosensitive area can deform due to the first biasing force exerted on the securing element by the first biased elastic element, wherein upon deformation of the thermosensitive area the cannula unit moves away from the secured position in the piercing direction under the first biasing force to a piercing position, and upon the cannula unit reaching the piercing position, the second cannula is configured to be moved away from the piercing position under the second biasing force to a retracted position while the first cannula remains in the piercing position.