Actuators conformational changes

Figure 26. An electric (ionic) pulse arrives from the brain through a nerve to the muscle, where it triggers conformational changes in proteins and chemical reactions. All the processes are three-dimensional. The generator (brain) is at the same time an ionic conductor. (Reprinted from T. F. Otero in Polymer Sensors and Actuators, Y. Osada and D. De Rossi, eds., Fig. 1, p., 19. Copyright 19XX. Reprinted with permission of Springer-Verlag.)...

X. Lin, J. Li, E. Smela, and S. Yip, Polaron-induced conformation change in single poly-pyrrole chain An intrinsic actuation mechanism, Int. J. Quantum Chem., 102 (5), 980 985 (2005). 

Conformational changes induced by the complexation of alkali cations have been analyzed experimentally and theoretically in oligothiophenes 89 and 90 specifically tailored to serve as model compounds for molecular actuation [197]. 

The third mechanism of actuation is based on changes in conformation of natural proteins (Table 2.1, entries 13 and 14). These systems incorporate a natural protein into the hydrogel that undergoes a conformation change and thus alters the characteristics of the material. The use of proteins as actuators is a new development in bio-responsive hydrogels. An example of this system was developed by Mrksich and co-workers [24]. In this study the functional nature of the hydrogel was given by the conformational properties of the protein calmodulin (CaM). Calmodulin has two distinct conformational states. In the presence of calcium ions, CaM has an extended, dumb-bell shaped conformation (extended CaM). 

---