Self-oscillating Gel Beating Like a Heart Muscle

Abstract

So far stimuli-responsive polymer gels and their application to smart materials have been widely studied. On the other hand, as a novel biomimetic gel, we have been studying gels with an autonomous self-oscillating function, since firstly reported in 1996. We succeeded in developing novel self-oscillating polymers and gels by utilizing the oscillating reaction, called the Belousov-Zhabotinsky (BZ) reaction. The self-oscillating polymer is composed of a poly(N-isopropylacrylamide) network in which the catalyst for the BZ reaction is covalently immobilized. In the presence of the reactants, the polymer gel undergoes spontaneous cyclic swelling-deswelling changes or soluble-insoluble changes (in the case of uncrosslinked polymer) without any on-off switching of external stimuli. Potential applications of the self-oscillating polymers and gels include several kinds of functional material systems, such as biomimetic actuators and mass transport surface.