  Despite advances in localization and navigation, aerial robots inevitably
remain susceptible to accidents and collisions. In this work, we propose a
passive foldable airframe as a protective mechanism for a small aerial robot. A
foldable quadrotor is designed and fabricated using the origami-inspired
manufacturing paradigm. Upon an accidental mid-flight collision, the deformable
airframe is mechanically activated. The rigid frame reconfigures its structure
to protect the central part of the robot that houses sensitive components from
a crash to the ground. The proposed robot is fabricated, modeled, and
characterized. The 51-gram vehicle demonstrates the desired folding sequence in
less than 0.15 s when colliding with a wall when flying.
