(Press-News.org) AMHERST, Mass. - Inspired by natural "snapping" systems like Venus flytrap leaves and hummingbird beaks, a team led by physicist Christian Santangelo at the University of Massachusetts Amherst has developed a way to use curved creases to give thin curved shells a fast, programmable snapping motion. The new technique avoids the need for complicated materials and fabrication methods when creating structures with fast dynamics.
The advance should help materials scientists and engineers who wish to design structures that can rapidly switch shape and properties, says Santangelo. He and colleagues, including polymer scientist Ryan Hayward, point out that until now, there has not been a general geometric design rule for creating a snap between stable states of arbitrarily curved surfaces.
"A lot of plants and animals take advantage of elasticity to move rapidly, yet we haven't really known how to use this in artificial devices," says Santangelo. "This gives us a way of using geometry to design ultrafast, mechanical switches that can be used, for example, in robots." Details of the new geometry appear in an early online issue of Proceedings of the National Academy of Sciences.
The authors point out, "While the well known rules and mechanisms behind folding a flat surface have been used to create deployable structures and shape transformable materials, folding of curved shells is still not fundamentally understood." Though the simultaneous coupling of bending and stretching that deforms a shell naturally gives items "great stability for engineering applications," they add, it makes folding a curved surface not a trivial task.
Santangelo and colleagues' paper outlines the geometry of folding a creased shell and demonstrates the conditions under which it may fold smoothly. They say the new technique "will find application in designing structures over a wide range of length scales, including self-folding materials, tunable optics and switchable frictional surfaces for microfluidics," such as are used in inkjet printer heads and lab-on-a-chip technology.
The authors explain, "Shape programmable structures have recently used origami to reconfigure using a smooth folding motion, but are hampered by slow speeds and complicated material assembly." They say the fast snapping motion they developed "represents a major step in generating programmable materials with rapid actuation capabilities."
Their geometric design work "lays the foundation for developing non-Euclidean origami, in which multiple folds and vertices combine to create new structures," write Santangelo and colleagues, and the principles and methods "open the door for developing design paradigms independent of length-scale and material system."
Other members of the team at UMass Amherst are Nakul Bende, Arthur Evans, Sarah Innes-Gold and Luis Marin, with physicist Itai Cohen at Cornell University. This work is funded by the National Science Foundation. END
ANN ARBOR--People who have not found their perfect fit in a career can take heart: There is more than one way to attain passion for work.
Contrary to popular wisdom, a love-at first-sight experience is not necessary when evaluating a potential job, according to a new University of Michigan study.
"The good news is that we can choose to change our beliefs or strategies to cultivate passion gradually or seek compatibility from the outset, and be just as effective in the long run at achieving this coveted experience," said Patricia Chen, a doctoral psychology student and ...
Researchers from North Carolina State University and the University of North Carolina at Chapel Hill have discovered how two important proofreader proteins know where to look for errors during DNA replication and how they work together to signal the body's repair mechanism.
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The discovery highlights a potential avenue for the treatment for chronic diseases.
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Led by researchers at Boston University School of Medicine (BUSM) and VA Boston Healthcare System, the review article currently appears online in the journal of Clinical Psychology Review.
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People who fear relationship conflicts are just as happy when they are single or in a relationship, according to new research published by the Society for Personality and Social Psychology.
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Water pollution has been a historical and stubborn problem in the water resource management. Several water pollution accidents continually occurred all over the world, threatening the safety of industry, agriculture and drinking water for resident's life (see Figure 1). An innovative and efficient approach was identified to study the complicated mechanism of water pollution in alluvial rivers.
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Researchers at the University of Strathclyde are developing groundbreaking plasma based light amplifiers that could replace traditional high power laser amplifiers.
The research group at the Glasgow-based University are leading efforts to take advantage of plasma, the ubiquitous medium that makes up most of the universe, to make the significant scientific breakthrough.
The next generation of high power lasers should be able to crack the vacuum to produce real particles from the sea of virtual particles. Example of these types of lasers can be found at the Extreme Light ...
New research by European and African scientists, including a team from the University of York, warns of the risks posed by the increasing air pollution over the cities of West Africa - amid fears it could have an impact on human health, meteorology and regional climate.
The atmosphere above West Africa is still one of the least studied and understood on the planet, despite its central role for the health and economic wellbeing of a large and increasing population.
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More than a quarter of a million people die each year from using smokeless tobacco, researchers at the University of York have concluded.
Millions more have their lives shortened by ill health due to the effects of chewing tobacco-based products, the study reveals.
Researchers say it is the first time the global impact of smokeless tobacco consumption on adults has been assessed.
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