Transformable Lattice with In-Situ Changeable Elastic Modulus Arising from Structural Interaction

Many efforts have been made for lattice design and fabrication for various applications, but most lattices possess fixed elastic modulus after fabrication, which impedes the development of multifunctional lattices. Here we propose a new lattice type that enables in-situ structural transformation and changeable elastic modulus. The structural interaction arises from opposite rotations of the rings from Yin and Yang patch of a lattice under compressive force. The distance between the Yin and Yang patch determines if interaction occurs and the lattice elastic modulus, which is decoupled with volume fraction. Here, numerical and experimental investigation were carried out to reveal the relationship between the interaction type, distance and stress-strain curve. Results show that the ratio of maximum to minimum elastic modulus of a lattice is 81.4 with six interaction bars on the ring, and we can obtain an exponential number of reprogrammable elastic moduli when combining multiple lattices as units to construct a cellular structure. Our work shows a potential for constructing intelligent lattices that can adapt to the surroundings.