Development of novel self-oscillating gel actuator for achievement of chemical robot

In our previous studies, we succeeded in construction self-oscillating gel actuator such as a self-walking gel and a dynamic motion of a gel actuator. However, the speed of the swelling-deswelling self-oscillation is too slow in order to realize practical chemical robot. In this study, 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. Moreover, 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 cause the swelling-deswelling self-oscillation in 0.5 Hz. The maximum frequency (0.5 Hz) of the novel gel was 20 times higher than that of the conventional-type self-oscillating gel. Moreover, we showed that the displacement of the self-oscillation for the gel has a trade-off relationship against the frequency of the self-oscillation.