), Japan, came up with a clever idea for a temperature compensation mechanism using a reaction called the Belousov–Zhabotinsky oscillating reaction.The key to their approach lies in soft, temperature-responsive gels made from poly, or ‘PNIPAAm’ for short, in which the BZ reaction can occur. These gels consist of polymeric strands that can accommodate a certain volume of solvent.
The researchers exploited this property of PNIPAAm gels by adding ruthenium sites on its constituent polymers. The periodic nature of the particular BZ reaction the researchers studied relies partially on the back-and-forth oxidation and reduction of ruthenium ions. Thus, the speed of this reaction is affected by the relative concentrations of solvent and Ru.
As the research team demonstrated through experimental measurements and a thorough mathematical analysis, the abovementioned effects combine to form a temperature-compensation mechanism that renders the period of the BZ reaction unaffected by shifts in temperature. “The prepared BZ gels exhibited temperature compensability just like the circadian rhythms observed in living organisms,” remarks Yamada.
Overall, this study demonstrates a completely new way to achieve temperature compensation in artificial biological clocks based on periodic reactions. Intriguingly, it’s even possible that similar temperature-compensation mechanisms using temperature-responsive soft bodies exist in biological systems in nature, as Yamada explains: “Our study suggests that temperature compensation can be naturally self-sustainable through the output system of circadian machinery.
Reference: “Artificial temperature-compensated biological clock using temperature-sensitive Belousov–Zhabotinsky gels” by Yuhei Yamada, Hiroshi Ito and Shingo Maeda, 27 December 2022,