A Pillbug-Inspired Morphing Mechanism Covered with Sliding Shells

The research proposes a new morphing structure inspired by how pillbugs move. Instead of mimicking the pillbug body directly, it uses a loop-coupled slider-crank mechanism to produce rolling-up and spreading motions that follow three target curves for shape morphing. To simplify control, the design reduces the mechanism’s degree of freedom to one by adding scissor mechanisms. The authors then attach 3D curved shells to the mechanism’s tracer points so the system can roll while being protected from attacks. A complete system combining the shells and the underlying morphing mechanism is developed through type and dimensional synthesis. The authors create a 3D model and test it to demonstrate shape-changing capability, and they build a robot with two modes: curling to roll down hills and spreading to move straight using wheels.