Patent ID: 8821440

Claim:
An injection device comprising: a dispensing chamber housing having a first part made of a first material and a second part made of a second material different from the first material, the first part thermally coupled to a needle, the second part having an inner surface and an outer surface, the inner surface partially defining a dispensing chamber for holding a quantity of a substance, the second part thermally coupled to the first part; a plunger engaged with an inner surface of the dispensing chamber housing, the plunger capable of sliding in the dispensing chamber housing, the plunger fluidly sealed to the inner surface of the dispensing chamber housing; and a temperature control device at least partially surrounding the dispensing chamber housing, the temperature control device for altering a temperature of the substance in the dispensing chamber; wherein the second material has a greater thermal coefficient than the first material such that when heat is applied to the dispensing chamber housing, the first part is at a higher temperature than the second part of the dispensing chamber.