Fig. 4: Inverse design of mechanical properties of Totimorphic lattices.

A Schematic of the inverse design pipeline. Reconfiguration is driven by gradient descent on a cost function, realised using automatic differentiation (autograd). B During optimisation, we obtain a continuous trajectory through configuration space (here represented using the first principal component of the angles representing the lattice) connecting the initial configuration (ν = 0) and the two final configurations (ν = ± 0.5). Since beams and levers are never deformed during reconfiguration, the lattice passes through all intermediate Poisson’s ratios while morphing. C Illustration of the final design for ν = 0.5 (left) and ν = − 0.5 (right), shown without (left) and with load (right, red arrows).