Current and foreseeable birth control methods require the user to make life choices involving safety, reliability, or permanent sterilization. The proposed solution is a fallopian tube occlusion device inserted via a hysteroscopic, transcervical procedure. This new device will add a safe, reliable and reversible choice of birth control methods. The device technology is based on modification of an existing shape-memory, polymeric, thermal-sensitive material, which will be rigid at room temperature for easy insertion and become soft and adaptive to the anatomy at body temperature. As this softening occurs, the material will expand to occlude the fallopian tube to prevent the passage of eggs and sperm rendering the patient infertile. The device may be removed to reestablish fertility. Phase I of this project will allow the development of a material formulation to achieve the required physical properties and permit limited feasibility testing. Existing materials are too stiff at body temperature for adaptation with the irregular shape of the human fallopian tube or lack the required strength for removal. Delivery and occlusion functionality will be tested in an animal tissue specimen. Commercialization of the device would be expected to command a significant share of the $3 billion contraceptive market.