A team led by physicist Christian Santangelo at the University of Massachusetts Amherst uses curved creases to give thin shells a fast, programmable snapping motion. The technique – inspired by the natural "snapping systems" like Venus flytrap leaves and hummingbird beaks – avoids the need for complicated materials and fabrication methods when creating structures with fast dynamics.

According to the researchers, the process will allow materials scientists and engineers to design structures that can rapidly switch shape and properties. Until now there has not been a general geometric design rule for creating a snap action between stable states of arbitrarily curved surfaces.

The geometry can be used in the development of ultrafast, mechanical robotics switches. The new technique may also find application in designing structures over a wide range of length scales, including self-folding materials, tunable optics, and switchable frictional surfaces for microfluidics.

Shape programmable structures have recently used origami to create a smooth folding motion, but they are hampered by slow speeds and complicated material assembly. The researchers' fast snapping motion will generate programmable materials with rapid actuation capabilities.


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