Synergistic Chemomechanical Oscillators: Periodic Gel Actuators without Oscillatory Chemical Reaction

Summary Synergistic chemomechanical oscillators fundamentally differ from BZ‐gels or ordinary pH‐actuators where oscillatory chemical reactions are required as (internal) “frequency generators”. Periodicity can arise from the interplay between a non‐periodic but nonlinear chemical reaction (e.g., a “pH‐switch”) and a geometrical feedback that modifies the transport time of species between the gel core and the environment. The experimental realization of several different such systems is essential to identify their universal properties. To be operational, the fine tuning of the gel's pH‐response to the region of the pH‐drop in a particular chemical reaction turned out to be an essential step. Simultaneously, the weak acid functional groups present in the gel modify the pH‐drop range, and this also needs to be considered. Analogous interdependence between chemical and physical actions is believed to be an underlying mechanism in primary biological processes.