Researchers in the US and Spain are joining forces to create BaTboT, a drone designed to mimic the flight pattern of bats. Partly funded by the US military, researchers are seeking ways to reduce energy cost during flight. Brown University found that bats use 35 percent less energy by folding their wings toward their bodies on the upstroke, and worked with Julian Colorado and his team at the Polytechnic University of Madrid to apply this knowledge to building a bat-like robot. The BaTboT uses shape memory alloy (SMA) actuators to mimic its biological counterpart's wing movement, extending and contracting when different electrical currents are applied. More details on the BaTboT's design are available in the joint research publication "Biomechanics of smart wings in a bat robot: morphing-wings using SMA actuators" authored by J Colorado, A Barrientos, C Rossi, and K Breuer.