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Botanical ratchets.
Ratcheting surfaces are a common motif in nature and appear in plant awns and grasses. They are known to proffer selective advantages for seed dispersion and burial. In two simple model experiments, we show that these anisotropically toothed surfaces naturally serve as motion rectifiers and generically move in a unidirectional manner, when subjected to temporally and spatially symmetric excitat...
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ژورنال
عنوان ژورنال: Nature
سال: 1978
ISSN: 0028-0836,1476-4687
DOI: 10.1038/274018a0