Fig. 1: Bi-level architected lattice metamaterials with active mode coupling.
A Prospective application of active lattices with mode coupling in adaptive wing morphing structures. B Active lattices with normal–shear mode coupling including visual representation through equivalent continua. C Representative volume element or unit cell for computing the homogenized mechanical behavior. Note that the lengths of upright (i.e. vertical) and slant members are taken as unequal here (h and L respectively), while the angle of the slant member BO with X-axis is θ. The joints in the unit cell (A, B, C and O) are indicated using blue color to differentiate these from sub-figure numbers. D Beam-level composite architecture with optimally placed active material (piezo) components. E Normal-shear mode coupling metamaterials resulting in tunable normal–torsion-bending coupling modes. F Prospective application of active mode coupling through periodic actuation for deformation-based locomotion in soft robotics. G Prospective exploitation of normal–shear mode coupling in aerodynamically adaptive wing morphing as aerofoil skin53. Note that the central theme of this paper is normal–shear coupling realized through piezo-active honeycombs as shown in the middle of the figure.
