CRIDROID – Bioinspired 4D-printed metacomposites: towards passive adaptive structures for space applications

Future space missions will have to contend with limited resources and large temperature variations. This thesis investigates structures capable of converting these variations into useful motion without motors. Inspired by the articulated stems of stalked crinoids, CriDroids are 4D-printed columnar metacomposites combining PA6.6 ossicles with continuous basalt-fibre/PA12 composite reinforcements deposited asymmetrically using a rotary printing process. Their architecture converts thermal expansion into reversible bending while maintaining the cohesion of the column. Laboratory tests establish the influence of geometry and reinforcement on deformation and demonstrate that the columns can lift loads weighing up to 25 times their own weight. Assembling modules with complementary orientations, actuation modes and response kinetics enables spatial configurations and sequential movements to be programmed under a common thermal stimulus. These capabilities are illustrated through experimental assemblies and concepts for adaptive structures. Finally, the potential of bioinspired 4D printing as a platform for reverse biomimetics is examined, with the aim of formulating and testing hypotheses about passive biological motion. This work establishes design principles for future adaptive metastructures intended for space applications, while also linking the development of passive adaptive structures to the investigation of architectural principles in biological systems.