Contraceptive implants are nothing new, but the current generation of progestogen-releasing devices need to be replaced every three years and have to be removed if you want to try for a baby. That may change soon, however, now that the Gates Foundation is backing a Massachusetts biotech company to build the next generation of implantable devices. MicroCHIPS Inc. is building a wirelessly controlled implant that slowly pumps out drugs and could, theoretically, only need replacing once every 16 years.

MicroCHIPS has been testing the "intelligent drug delivery system" with osteoporosis patients who would otherwise require a daily barrage of injections. Bill-and-Melinda Gates and MIT's Robert Langer, however, believe that the technology could solve the family planning crisis that exists in the world's poorest countries. Reservoirs of levonogestrel, a contraceptive hormone would be kept inside the 1.5cm device, and could be activated and deactivated at the whims of the user with some sort of wireless device. Currently in the experimentation stage, the team hope to solve the issue of security -- to prevent anyone but the user controlling the system -- before submitting it for FDA approval at some point in the near future.