Shape memory polymers (SMPs) belong to a class of smart polymers, which have drawn considerable research interest in last few years because of their applications in microelectromechanical systems, actuators, for self healing and health monitoring purposes, and in biomedical devices. Like in other fields of applications, SMP materials have been proved to be suitable substitutes to metallic ones because of their flexibility, biocompatibility and wide scope of modifications. The shape memory properties of SMPs polymers might surpass those of shape memory metallic alloys (SMAs). In addition to block copolymers, polymers blends and interpenetrating network structured SMP systems have been developed. The present review mainly highlights the recent progress in synthesis, characterization, evaluation, and proposed applications of SMPs and related composites.

Recent advances in shape memory polymers and composites : a review

We propose a simple theory describing the influence of nanoparticles on thermodynamics of binary polymer mixture. In particular, we consider the case in which nanoparticles preferentially segregate into one of the polymeric components. Depending on the particle radius Rp and the polymer degree of polymerization N, addition of nanoparticles can either promote or hinder mixing of the polymers. We calculate how the addition of nanoparticles shifts the spinodal of the polymer blend. These results help to improve understanding of recent simulations on the dynamics of polymer/particle mixtures.

Influence of Nanoparticles on Miscibility of Polymer Blends. A Simple Theory

A novel biodegradable multiblock poly(ester urethane) containing poly(L-lactic acid) and poly(butylene succinate) blocks

Artificial muscles composed of carbon nanotube yarns have previously demonstrated fast, large-angle rotations. Here, the authors infiltrate carbon nanotube yarns with a paraffin wax and polystyrene-based copolymer mixture, achieving stable 9,800 r.p.m. rotation without apparent oscillation.

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Hybrid carbon nanotube yarn artificial muscle inspired by spider dragline silk

Shape memory polymers (SMP) belong to the class of stimuli-responsive materials and have generated significant research interest. Their capability to retain an imposed, temporary shape and to recover the initial, permanent shape upon exposure to an external stimulus depends on the "functional determinants", which in simplistic terms, can be divided into structural/morphological and processing/environmental factors. The primary aim of the first part of this review is to reflect the knowledge about these fundamental relationships. In a next step, recent advances in shape memory polymer composites are summarized. In contrast to earlier reviews, studies on the impairment of shape memory properties through various factors, such as aging, compression and hibernation, lubricants, UV light and thermo-mechanical cycling, are extensively reviewed. Apart from summarizing the state-of-the-art in SMP research, recent progress is commented.

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Review on the Functional Determinants and Durability of Shape Memory Polymers

PROBLEM TO BE SOLVED: To provide a compact and light power generation device with which high electric capacitance may be expected.SOLUTION: The power generation device includes: a composite conductive material layer containing insulating polymer which is to be a matrix and at least one kind of conductor; and electrodes disposed at both surfaces or both ends of the composite conductive material layer. Electric conductivity of the power generation device is equal to or more than 10S/m and equal to or less than 10 S/m.

Kiyohiro Inoue

Papers

Power generation device