Multistable sheets with rewritable patterns for switchable shape-morphing

Flat sheets patterned with folds, cuts or swelling regions can deform into complex three-dimensional shapes under external stimuli1–24. However, current strategies require prepatterning and lack intrinsic shape selection5–24. Moreover, they either rely on permanent deformations6,12–14,17,18, preventing corrections or erasure of a shape, or sustained stimulation5,7–11,25, thus yielding shapes that are unstable. Here we show that shape-morphing strategies based on mechanical multistability can overcome these limitations. We focus on undulating metasheets that store memories of mechanical stimuli in patterns of self-stabilizing scars. After removing external stimuli, scars persist and force the sheet to switch to sharply selected curved, curled and twisted shapes. These stable shapes can be erased by appropriate forcing, allowing rewritable patterns and repeated and robust actuation. Our strategy is material agnostic, extendable to other undulation patterns and instabilities, and scale-free, allowing applications from miniature to architectural scales. To demonstrate the power of multistability, a specific class of groovy metasheets is introduced as a new shape-morphing platform that allows repeated switching from the flat state to multiple, precisely selected and stable three-dimensional shapes.