Programmable Double Network Gel: Interspecies interactions determine structure, resilience and adaptability

New research shows how the interactions between two different network-forming species within a softgel can be fine-tuned, allowing programmable control of their structure and mechanical properties. The findings reveal a powerful framework for engineering next-generation soft materials with customizable behaviors inspired by the complexity of biological tissues.

The study, entitled “Interspecies interactions in dual, fibrous gels allow for control of gel structure and rheology,” is published in the minutes of the National Academy of Sciences.

In this study, we use simulations to investigate how the strength and geometry of interactions between two colloidal species affect network formation and rheological performance. By controlling interspecies stickiness and tendency to bound individually, the researchers found that by regulating these interspecies interactions, they could precisely control whether the networks formed are individual, overlapping, or intertwined.

The key findings are as follows:

In general, reducing interspecies viscosity leads to more severe double-network materials. However, these materials vary widely depending on the network architecture. The tendency to bundle allows networks to interpenetrate and strengthen each other, increasing toughness. The double network architecture itself becomes a design principle for creating more resilient or more tunable materials.

Importantly, this study shows that entangled networks are reprogrammable. In other words, gels can be formed by altering interspecies interactions. This discovery opens the door to materials that adapt mechanisms in response to environmental cues and external triggers.

Besides providing new insights into soft matter physics, this work has broad implications for material design for biomedicine, tissue engineering, soft robotics and smart materials. Systems that mimic the cooperative behavior of biological networks can lead to more versatile and functional synthetic materials.

Impact on future research

Future research will explore how these principles can be realized experimentally in colloidal or polymer systems, and how interspecies interactions can be exploited to design materials that respond to changes in light, temperature, or chemical, or, instead, highly robust to those changes.

Understanding the rules for managing multi-network dynamics with soft materials can ultimately enable solutions tailored to applications that require strength, flexibility and responsiveness in one integrated material.