Water Triggered Shape Memory Materials

Water - triggered shape memory of multiblock thermoplastic polyurethanes ( TPUs ) 3

In this article we describe the preparation and characterization of a water-triggered shape memory polymer (SMP) family, PCL–PEG based thermoplastic polyurethanes (TPUs). Upon immersion in water, water molecules selectively swelled the hydrophilic PEG domains, resulting in durable hydrogels with strain-to-failure values greater than 700%. Dry samples fixed in a temporary shape underwent watertr...

Animal Hairs as Water-stimulated Shape Memory Materials: Mechanism and Structural Networks in Molecular Assemblies

Animal hairs consisting of α-keratin biopolymers existing broadly in nature may be responsive to water for recovery to the innate shape from their fixed deformation, thus possess smart behavior, namely shape memory effect (SME). In this article, three typical animal hair fibers were first time investigated for their water-stimulated SME, and therefrom to identify the corresponding net-points an...

A Thermodynamical Constitutive Model for Shape Memory Materials. Part I. the Monolithic Shape Memory Alloy

Pseudoelasticity and the shape memory e ect (SME) due to martensitic transformation and reorientation of polycrystalline shape memory alloy (SMA) materials are modelled using a free energy function and a dissipation potential. Three di erent cases are considered, based on the number of internal state variables in the free energy: (1) Austenite plus a variable number of martensite variants; (2) ...

Controlling the martensitic transition in Heusler shape-memory materials

A Viewpoint on: Role of Electronic Structure in the Martensitic Phase Transition of Ni2Mn1+xSn1−x Studied by Hard-X-Ray Photoelectron Spectroscopy and Ab Initio Calculation M. Ye, A. Kimura, Y. Miura, M. Shirai, Y. T. Cui, K. Shimada, H. Namatame, M. Taniguchi, S. Ueda, K. Kobayashi, R. Kainuma, T. Shishido, K. Fukushima and T. Kanomata Phys. Rev. Lett. 104, 176401 (2010) – Published April 26, ...

NiTi Shape Memory Alloys, Promising Materials in Orthopedic Applications