Control of autonomous swelling-deswelling behavior for a polymer gel.

We succeeded in the wide-range control of the period for the swelling-deswelling self-oscillation of a novel polymer gel by selection of the initial concentration of the Belouzov-Zhabotinsky (BZ) substrates and the temperature. The novel polymer gel was composed of a non-thermoresponsive and biocompatible poly(vinylpyrrolidone) (PVP) main chain covalently bonded to the ruthenium catalyst for the BZ reaction. In this study, we clarified the influence of the initial concentration of the BZ substrates and the temperature on the period and the self-oscillating behavior. By optimizing the initial concentration of the BZ substrates, we caused the swelling-deswelling self-oscillation in 0.5 Hz. The maximum frequency (0.5 Hz) of the novel gel was 20 times as large as that for the conventional-type self-oscillating gel. Moreover, we showed that the displacement of the self-oscillation for the gel has a tradeoff relationship against the period of the self-oscillation.