Self-Oscillating Polymer Gels as Novel Smart Materials

As a novel biomimetic polymer gel, we have been studying polymer gels with an autonomous self-oscillating function, since firstly reported in 1996. For developing the polymer gels, we utilized oscillating chemical reaction, called the Belousov-Zhabotinsky (BZ) reaction, which is recognized as a chemical model for understanding several autonomous phenomena in biological systems. The self-oscillating polymer gel is composed of a poly(N-isopropylacrylamide) network in which the metal catalyst for the BZ reaction is covalently immobilized. Under the coexistence of the reactants, the polymer undergoes spontaneous swelling-deswelling changes (in the case of gel) or cyclic soluble-insoluble changes (in the case of an uncrosslinked polymer) without any on-off switching of external stimuli. Several kinds of functional material systems utilizing self-oscillating polymers and gels such as biomimetic actuators, mass transport surface, etc. are expected. Here recent progress on self-oscillating polymers and gels and the design of functional material systems are summarized.