A Multidirectional Superelastic Organic Crystal by Versatile Ferroelastical Manipulation

Mechanical twinning changes atomic, molecular, and crystal orientations along with directions of the anisotropic properties of the crystalline materials while maintaining single crystallinity in each domain. However, such deformability has been less studied in brittle organic crystals despite their remarkable anisotropic functions. Herein we demonstrate a direction‐dependent mechanical twinning that shows superelasticity in one direction and ferroelasticity in two other directions in a single crystal of 1,3‐bis(4‐methoxyphenyl)urea. The crystal can undergo stepwise twinning and ferroelastically forms various shapes with multiple domains oriented in different directions, thereby affording a crystal that shows superelasticity in multiple directions. This adaptability and shape recoverability in a ferroelastic and superelastic single crystal under ambient conditions are of great importance in future applications of organic crystals as mechanical materials, such as in soft robotics. Zurechtgebogen: Bei einem Einkristall aus 1,3‐Bis(4‐methoxyphenyl)harnstoff konnte gezeigt werden, dass er durch mechanische Zwillingspaarung Superelastizität (SE) in einer Richtung und Ferroelastizität (FE) in zwei anderen Richtungen zeigt. Der Kristall wurde stufenweise verpaart und bildet ferroelastisch verschiedene Formen mit mehreren in verschiedenen Richtungen orientierten Domänen, was zur Superelastizität des Kristalls in mehreren Richtungen führt.