A portable, mechanical (non-electric) device designed to provide basal and/or periodic bolus subcutaneous delivery of insulin to a patient with diabetes mellitus. It may be badge-like, designed to adhere to skin or clothing (e.g., with a pressure-sensitive adhesive), or worn in a case attached to the belt or carried in a pocket. The device typically integrates a needle(s)/infusion cannula and an insulin reservoir; it is patient operated (e.g., by squeezing/pressing buttons) and may be daily-disposable or used for several days before being discarded. This is a single-use device.