Responsive hydrogels can sense environmental stimuli and respond as actuators by expelling water and changing shape. In this Letter, we develop theory to demonstrate that groups of responsive hydrogels can also communicate with each other, by utilizing the effect of elastic deformation on chemical reaction dynamics. Specifically, we consider a system of two spatially separated chemically responsive hydrogels suspended in a solution in which a Belousov-Zhabotinsky (BZ)-type reaction occurs. Solving for the gel dynamics with the transport of solvent through the poroelastic network and the chemical kinetics, we show how the periodic swelling-deswelling oscillations of each gel can become coupled, and how this coupling can be exploited to send signals from one gel to the other via mechanical manipulation of the sender that affect the local (and thus global) frequency of oscillation.

oscillating systems were nonexistent. While theoretical discussions date back to around 1910, the systematic study of oscillating chemical reactions and In chemistry, a chemical oscillator is a complex mixture of reacting chemical compounds in which the concentration of one or more components exhibits periodic changes. They are a class of reactions that serve as an example of non-equilibrium thermodynamics with far-from-equilibrium behavior. The reactions are theoretically important in that they show that chemical reactions do not have to be domin In chemistry, a chemical oscillator is a complex mixture of reacting chemical compounds in which the concentration of one or more components exhibits periodic changes. They are a class of reactions that serve as an example of non-equilibrium thermodynamics with far-from-equilibrium behavior. The reactions are theoretically important in that they show that chemical reactions do not have to be dominated by equilibrium thermodynamic behavior. In cases where one of the reagents has a visible color, periodic color changes can be observed. Examples of oscillating reactions are the Belousov–Zhabotinsky reaction (BZ reaction), the Briggs–Rauscher reaction, and the Bray–Liebhafsky reaction. Chemical systems cannot oscillate about a position of final equilibrium because such an oscillation would violate the second law of thermodynamics. For a thermodynamic system which is not at equilibrium, this law requires that the system approach equilibrium and not recede from it. For a closed system at constant temperature and pressure, the thermodynamic requirement is that the Gibbs free energy must decrease continuously and not oscillate. However it is possible that the concentrations of some reaction intermediates oscillate, and also that the rate of formation of products oscillates. Theoretical models of oscillating reactions have been studied by chemists, physicists, and mathematicians. In an oscillating system the energy-releasing reaction can follow at least two different pathways, and the reaction periodically switches from one pathway to another. One of these pathways produces a specific intermediate, while another pathway consumes it. The concentration of this intermediate triggers the switching of pathways. When the concentration of the intermediate is low, the reaction follows the producing pathway, leading then to a relatively high concentration of intermediate. When the concentration of the intermediate is high, the reaction switches to the consuming pathway. Different theoretical models for this type of reaction have been created, including the Lotka-Volterra model, the Brusselator and the Oregonator. The latter was designed to simulate the Belousov-Zhabotinsky…

We report a novel "intelligent" gel that undergoes an autonomous swellingdeswelling oscillation without reliance on an alteration in external conditions. The mechanical oscillation in our gel system was produced via oscillating chemical reaction similar to metabolic reaction, called the Belousov-Zhabotinsky (BZ) reaction. We prepared gels composed of crosslinked Nisopropylacrylamide (NIPAAm) networks to which ruthenium tris(2,2'-bipyridine) (Ru(bpy) 3 ), a catalyst for the BZ reaction, was covalently bonded. The BZ reaction occurring within the gel matrix generates periodic redox changes of th

Species ranging from single-cell organisms to social insects can undergo auto-chemotaxis, where the entities move towards a chemo-attractant that they themselves emit. Polymer gels undergoing the self-oscillating Belousov–Zhabotinsky (BZ) reaction exhibit autonomous, periodic pulsations, which produce chemical species collectively referred to as the activator. The diffusion of this activator into the surrounding solution affects the dynamic behavior of neighboring BZ gels and hence, the BZ gels not only emit, but also respond to self-generated chemical gradients. This review describes recent e

Department of Chemistry, University College of Science, 92, A P C Road, Calcutta-700 009 Manuscript received 17 November 1994, revised 31 March 1995, accepted 22 May 1995 B-Z oscillating chemical reaction has been studied using gallic acid as the substrate in a new acid medium, namely, perchloric acid medium, both visually and potentiometrically side by side by batch method. Various concentrations of perchloric acid have been used and both uncatalysed and catalysed reactions using ferroin have been studied. The reaction has also been followed in presence of different amounts of acetone. The re

Patterns of colloidal origin that are formed in ionic precipitation-diffusion systems and are known as Liesegang Rings (LR) have fascinated researchers since the beginning of the century and have been the subject of numerous theoretical, numerical, and experimental studies. The terms recurrent, rhythmic, or periodic precipitation are often used to describe the temporal pattern evolution in such systems. Pattern formation in the vapor phase reaction of NH_3 and HCl has also been reported since 1930. It has been suggested that any reaction giving an insoluble product is capable of LR pattern for

Pattern formation is a ubiquitous phenomenon in animate and inanimate systems generated by mass transport and reaction of chemical species. The Liesegang phenomenon is a self-organized periodic precipitation pattern always studied in porous media such as hydrogels and aerogels for over a century. The primary consideration of applying the porous media is to prevent the disintegration of the precipitation structures due to the sedimentation of the precipitate and induced fluid flow. Here, we show that the periodic precipitation patterns can be engineered using a Hele-Shaw cell in a confined liqu

Dynamical processes in many engineered and living systems take place on complex networks of discrete dynamical units. We present laboratory experiments with a networked chemical system of nickel electrodissolution in which synchronization patterns are recorded in systems with smooth periodic, relaxation periodic, and chaotic oscillators organized in networks composed of up to twenty dynamical units and 140 connections. The reaction system formed domains of synchronization patterns that are strongly affected by the architecture of the network. Spatially organized partial synchronization could b