Non-linear interaction via disordered structures for complex picking

Entanglement often occurs in a cluster of objects that stochastically interact with each other. This interaction is particularly influenced by the object's geometric features and material properties. A tangled media can be considered a disordered and discrete mechanical metamaterial with highly random attributes and interactions. Here, we employ an external electromagnetic field as a stimulus to form a structure consisting of U-shaped ferromagnetic particles which are inherently prone to tangle. We then harness such disordered composition to create non-linear interactions with non-ferromagnetic objects. The results show a rich domain of physical engagement behaviour between the constructed metamaterial and various fabricated objects, which have specific geometric features and a range of bending stiffnesses. We use this new concept in complex robotic picking tasks, where conventional grippers struggle. We further enhance our set-up by manufacturing 3D-printed dissolvable ferromagnetic particles, which are able to pick entangled objects such as fresh herbs and spaghetti and decompose once the task is completed.