Achieving Superior Tensile Performance in Individual Metal-Organic Framework Crystals

Rapid advances in the engineering application prospects of metal-organic framework (MOF) materials necessitate an urgent in-depth understanding of their mechanical properties. This work demonstrates unprecedented recoverable elastic deformation of Ni-tetraphenylporphyrins (Ni-TCPP) MOF nanobelts with a tensile strain as high as 14%, and a projected yield strength-to-Young's modulus ratio exceeding the theoretical limit (≈10%) for crystalline materials. Based on first-principles simulations, the observed behavior of MOF crystal can be attributed to the mechanical deformation induced conformation transition and the formation of helical configuration of dislocations under high stresses, arising from their organic ligand building blocks in the crystal structures. The investigations of the mechanical properties along with electromechanical properties demonstrate that MOF materials have exciting application potential for biomechanics integrated systems, flexible electronics, and nanoelectromechanical devices.