Researchers use soft polymers swollen in water capable to provide a fascinating variety of responses upon environmental stimuli to mimic soft, elastic and deformable tissues of living organisms. The arrangement of the laser, gels and mirror creates a feedback loop that keeps the gels at a specific temperature. The researchers built touch-responsive triggers on top of the feedback system by adding 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 team designed two systems that respond to different types of touch. In one case, a single touch triggers the response, just as a touch-me-not plant folds its leaves when stroked. The second setup only responds to repeated touches, in the same way as a Venus flytrap needs to be touched twice in 30 seconds to make it snap shut.
The article Feedback controlled hydrogels with homeostatic oscillations and dissipative signal transduction was published in Nature Nanotechnology on 28 November, 2022. Read more…