Researchers at Aalto University and Tampere University have developed a synthetic system that responds to environmental changes in the same way as living organisms, using feedback to maintain its internal conditions. 

This makes it possible to create mechanisms that respond dynamically to the environment – an important feature for interactive materials and soft robotics.

“The tissues of living organisms are typically soft, elastic and deformablе. The gels used in our system are similar. They are soft polymers  swollen in water, and they can provide a fascinating variety of responses upon environmental stimuli”

says Hang Zhang, an Academy of Finland postdoctoral researcher at Aalto who was one of the lead authors of the study.

Researchers at Aalto University and Tampere University have developed a system of materials that maintains its state in a manner similar to living systems. The new system consists of two side-by-side gels with different properties. Interactions between the gels make the system respond homeostatically to environmental changes, keeping  its temperature within a narrow range when stimulated by a laser.

“Like a living system, our homeostatic system is dynamic. The temperature oscillates around the threshold, but the range of the oscillation is pretty small and is robust to outside disturbances. It’s a robust homeostatic system”,

says Hao Zeng, an Academy of Finland research fellow at Tampere University who was the other lead author of the study.

The researchers built touch-responsive triggers on top of the feedback system. To accomplish this, they added mechanical components that respond to changes in temperature. Touching the gel system in the right way pushes it out of its steady state, and the resulting change in temperature causes the mechanical component to deform. Afterwards, everything returns to its original condition.

The researchers also showed how  the homeostatic system could control a dynamic colour display or even push cargo along its body. They emphasize that these demonstrations  showcase only a handful of the possibilities opened up by the new material concept.