  With inspiration from arthropods' exoskeletons, we designed a simple, easily
manufactured, semi-rigid structure with flexible joints that can passively damp
impact energy. This exoskeleton fuses the protective shell to the main robot
structure, thereby minimizing its loss in payload capacity. Our design is
simple to build and customize using cheap components and consumer-grade 3D
printers. Our results show we can build a sub-250g, autonomous quadcopter with
visual navigation that can survive multiple collisions, shows a five-fold
increase in the passive energy absorption, that is also suitable for automated
battery swapping, and with enough computing power to run deep neural network
models. This structure makes for an ideal platform for high-risk activities
(such as flying in a cluttered environment or reinforcement learning training)
without damage to the hardware or the environment.
