A fluid dispensing device comprising: a reusable unit (I) comprising: a controller (101) for managing operations, and an engine (103) for imparting motion to a fluid transfer element (105) of a fluid transfer system, a first portion of the fluid transfer element (105) being disposed in the reusable unit (I) a depletable unit (II) comprising: a secondary portion of the fluid transfer element (105) of the fluid transfer system, a reservoir (203) for holding the fluid, a tube (205) coupled to the reservoir (203) for delivery of the fluid from the reservoir (203), and a well (206) coupled in fluid communication with the tube (205) and an injection unit (III) configured to be inserted into the depletable unit (II) at the well (206), the injection unit (III) comprising: a cannula (305) for insertion into a body of a user through the well (206), and a penetrating means (303) fitted to the cannula (305) and having a sharp tip (3031) for piercing through a skin (S) of the user wherein transfer of fluid out of the depletable unit (II) for injection occurs when the reusable unit (I) and the depletable unit (II) are coupled in operative association and the injection unit (III) is coupled to provide fluid communication with the depletable unit (II), on condition that power is supplied to the engine (103).
