Variable Stiffness Tensegrity Mechanism

We propose a variable stiffness tensegrity mechanism that enables switching of the overall structural stiffness by integrating a one-dimensional variable stiffness mechanism into the tensile elements of a tensegrity structure. By applying this mechanism to a drone's spherical shell, the system can protect the drone from external environmental contact—one of its inherent vulnerabilities—while allowing state transitions in response to environmental conditions. The proposed mechanism permits deformation and recovery in the low-stiffness mode, and functions as a rigid body in the high-stiffness mode. In this study, we conceptualize the principle, fabricate a prototype, and experimentally verify the feasibility of stiffness switching using the developed system.