This week we learned about a tiny robotic stingray bioengineered from rat heart muscle that can navigate an obstacle course, 3D-printed “micro-rockets” made from biodegradable silk that could one day target cancer in the body like a missile, and a programmable genetic vaccine against Ebola, malaria and the flu that can be made in just seven days and was 100 percent effective in tests in mice. Read on if you dare!