Shape memory polymers other

Other materials have been found that have shape memories. Shape-memory polymers are plastics that have properties similar to SMAs. Pliable materials have recently been found that can be stretched up to twice their normal length, yet regain their shape when heated. Having a smart plastic material opens up applications of a softer, more flexible nature, such as clothing. 

Shape memory polymers, as well as the other developmental embolic materials discussed here, represent insight into future procedures that may revolutionize the practice of endovascular embolization in order to better treat critical vascular conditions. 

Stimuli-responsive materials have sparked enormous interest in recent years due to their potential applications in micro-machines, soft robots, biomedical systems, etc. [1-6]. A variety of intelligent polymeric materials such as shape memory polymers [7, 8], polymer gels [9, 10], conducting polymers [11, 12], and dielectric elastomers [13,14] have been developed for these applications. Compared to other stimulus-driven methods including pressure [15], heat [16, 17], electric field... 

Obviously, the stress recovery ratio is much lower than the strain recovery ratio. The difference is even bigger for cold-drawing programming. In other words, the SMPF has a good memory of strain or shape, but a poor memory of stress or load. Actually, this is trae not only for SMPFs but also for almost all shape memory polymers. On the one hand, this shows the limitations of SMPs in certain applications, such as those that need a large recovery force. On the other hand, this also provides a unique opportunity for researchers to develop SMPs with a higher recovery stress and a higher stress recovery ratio. 

As mentioned in Chapter 8, some vegetable oil-based polymers exhibit shape memory properties. The discovery of smart materials is one of the revolutionary steps in the held of active materials research. Among different types of smart materials (metals, alloys and ceramics), shape memory polymers (SMPs) have attracted considerable research interest in last few years because of their advantages over other categories of materials, as discussed in Chapter 1. Shape memory polymers which are deformed and... 

Conventional shape memory polymers are segmented polyfur-ethane) s and have hard segments that include aromatic moieties (70,71). But a series of other thermoplastic block copolymers with thermally induced shape memory effects have been summarized (69). 

Fig. 2 Literature and patent analysis for the time period 1907-2008 according to pubUcadon date for the scientific publications and filing date for patents/patent applications. In all cases plural and singular forms of search terms were considered, (a) Result of literature search for shape-memory polymer in CAPlus database performed with Scifinder on March 12th, 2009 white - publications in English, gray - publications in Chinese or Japanese, black - other languages (b) result of two literature searches shape-memory gel, heat shrinkable polymer (all languages) performed in CAPlus database with Scifinder on March 12th, 2009 black - shape-memory gel, white - heat shrinkable polymer (c) result of patent search (issued patents and patent applications) for shape-memory polymer performed in DEPATIS database on Feb 27th, 2009 white - shape-memory polymer (d) result of patent search (issued patents and patent applications) for shape-memory gel, heat shrinkable article performed in DEPATIS database performed on Feb 27th, 2009 black - shape-memory gel, white - heat shrinkable article ...

Polymers are promising candidates for new actuation technologies. Several classes of polymeric compounds can convert electrical energy (or other sources of energy, such as heat, light and chemical gradients) into mechanical work, so as to effect the movement of loads. Piezoelectric and shape memory polymers are among the most well known representatives of polymer actuators. 

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