Biomechanics of morphing wings in a Bat-robot actuated by SMA muscles

Bats exhibit extraordinary flight capabilities that arise by virtue of a variety of unique mechanical features. These flying mammals have developed powerful muscles that provide the folding and extension of their wing-membrane during flight (morphing). Although observing and gaining inspiration from these animals can provide significant insight into the physical requirements of flapping flight, it remains an engineering challenge to develop equivalently effective morphing wing vehicles [1], [2]. Bat wings are made of quite flexible bones that possess independently controllable joints, which make difficult to mimic their mechanistic basis of flight. By combining flapping and morphing motions, bats can achieve an amazing level of maneuverability [3]. Attempting to reproduce the muscles system acting on their wing’s joints requires the analysis of alternative actuation technologies [4] more likely muscle fiber arrays instead of standard servomotor actuators. In this regard, smart materials have opened new alternatives and the potential of building simpler, lighter and smaller robotics systems [5], [6].