Bending and twisting with a pinch: Shape morphing of creased sheets

In this letter, we introduce a unique behavior seen in creased sheets where localized changes the folding (i.e., pinch) result global bending and twisting deformations. Using isometric deformation theory, identify connections between pinching, crease curvature, torsion that begin to explain shape-morphing behavior. Given limitations of deformations, expand our understanding using mechanics-based bar hinge model sheets, sheet is allowed stretch. With tool, found increase curvature due pinching are proportional before curved creases facilitate twisting. Additionally, explored with more than one crease. We an even number generate intense those odd experience when straight. The had little effect on pinch-induced origami. stiffness amount twisting, but greater spacing resulted Based these results, created framework design patterns have desirable can be coupled or not, demonstrated programmability simulations by physical prototypes. Our findings enable shape morphing low-complexity input versatile output. • Local generates bending/twisting controlled pattern geometry. Deformations reversible depending design. Sheets used for applications. Pinch-actuation offers