Design of multi-state and smart-bias components using Shape Memory Alloy and Shape Memory Polymer composites

A Multifunctional Smart Material System (MSMS) consists of two or more different smart material phases in the form of a hybrid system, in which every phase performs a different but necessary function. In this work, thermally responsive Shape Memory Alloys (SMAs) and Shape Memory Polymers (SMPs) are combined to form a MSMS. The transformation temperatures martensitic start (M-s), martensitic finish (M-f), austenitic start (A(s)) and austenitic finish (A(f)) of SMA and the glass transition (T-g) for the SMP play a critical role in designing such a MSMS. Multi-state smart bias systems with varying stiffnesses can be obtained by varying the T-g of SMP between the transformation temperatures M-f and A(f) of SMA. Guidelines to form such MSMS have been established by estimating the volume fractions of the individual constituents. Various ideas for smart-bias tools/devices have been proposed, such that they can operate under three different temperature regimes, with one material constituent being passive and the other active at a given temperature. (C) 2012 Elsevier Ltd. All rights reserved.