  This paper presents the technique of flex-and-flip manipulation. It is
suitable for grasping thin, flexible linear objects lying on a flat surface.
During the manipulation process, the object is first flexed by a robotic
gripper whose fingers are placed on top of it, and later the increased internal
energy of the object helps the gripper obtain a stable pinch grasp while the
object flips into the space between the fingers. The dynamic interaction
between the flexible object and the gripper is elaborated by analyzing how
energy is exchanged. We also discuss the condition on friction to prevent loss
of contact. Our flex-and-flip manipulation technique can be implemented with
open-loop control and lends itself to underactuated, compliant finger
mechanism. A set of experiments in robotic page turning performed with our
customized hardware and software system demonstrates the effectiveness and
robustness of the manipulation technique.
