Using a custom-made silicon skin and articulated morphing wings, researchers from the California Institute of Technology and the University of Illinois at Urbana-Champaign created Bat Bot (B2), an autonomous flying robot that successfully mimics the flight characteristics of real bats. The Bat Bot weighs only 93 grams and has a roughly one-foot wingspan. It can alter its wing shape by flexing, extending, and twisting at its shoulders, elbows, wrists, and legs. Bats have the most sophisticated powered flight mechanism among animals, which includes wings that have the capability of changing shape. Their flight mechanism involves several different types of joints that interlock the bones and muscles to one another, creating a musculoskeletal system that is capable of movement in more than 40 rotational directions.