  Most aerial manipulators use serial rigid-link designs, which results in
large forces when initiating contacts during manipulation and could cause
flight stability difficulty. This limitation could potentially be improved by
the compliance of continuum manipulators. To achieve this goal, we present the
novel design of a compact, lightweight, and modular cable-driven continuum
manipulator for aerial drones. We then derive a complete modeling framework for
its kinematics, statics, and stiffness (compliance). The modeling framework can
guide the control and design problems to integrate the manipulator to aerial
drones. In addition, thanks to the derived stiffness (compliance) matrix, and
using a low-cost IMU sensor to capture deformation angles, we present a simple
method to estimate manipulation force at the tip of the manipulator. We report
preliminary experimental validations of the hardware prototype, providing
insights on its manipulation feasibility. We also report preliminary results of
the IMU-based force estimation method.
