Self-oscillating polymer gels as novel biomimetic materials

Stimuli-responsive polymer gels and their application to smart materials have been widely studied. On the other hand, as a novel biomimetic gel, we developed gels with an autonomous self-oscillating function like a heart muscle, which was firstly reported in 1996. We designed the self-oscillating polymers and gels by utilizing the oscillating reaction, called the Belousov-Zhabotinsky (BZ) reaction as a chemical model of the TCA cycle. The self-oscillating polymer is composed of a poly(N-isopropylacrylamide) network in which the metal catalyst for the BZ reaction is covalently bonded. In a closed solution containing the reactants other than the catalyst, the polymer gel undergoes spontaneous cyclic swelling-deswelling changes without any on-off switching of external stimuli. Their potential applications include several kinds of functional material systems, such as biomimetic actuators and mass transport surface. Here recent progress on the novel polymer gels is introduced.