A wearable infusion device for delivering medication into body of a user, the infusion device comprising a medication container containing a volume of medication to be dispensed； an infusion needle that is fully enclosed in a sterile environment until the infusion needle is inserted into underlying tissue； an infusion needle insertion mechanism associated with the infusion needle, powered by one or more mechanical springs, that when activated, inserts the infusion needle through the skin into underlying tissue； means for delivering medication out of the medication container and into underlying tissue via the infusion needle； and a housing associated with the medication container, the infusion needle, the infusion needle insertion mechanism and the means for delivering medication.
