Structural transition from helices to hemihelices.
Helices are amongst the most common structures in nature and in some cases, such as tethered plant tendrils, a more complex but related shape, the hemihelix forms. In its simplest form it consists of two helices of opposite chirality joined by a perversion. A recent, simple experiment using elastomer strips reveals that hemihelices with multiple reversals of chirality can also occur, a richness not anticipated by existing analyses. Here, we show through analysis and experiments that the transition from a helical to a hemihelical shape, as well as the number of perversions, depends on the height to width ratio of the strip's cross-section. Our findings provides the basis for the deterministic manufacture of a variety of complex three-dimensional shapes from flat strips.
School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts, United States of America.
Jia
J
Liu
School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts, United States of America.
Jiangshui
J
Huang
School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts, United States of America.
Tianxiang
T
Su
School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts, United States of America; Kavli Institute, Harvard University, Cambridge, Massachusetts, United States of America.
Katia
K
Bertoldi
School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts, United States of America; Kavli Institute, Harvard University, Cambridge, Massachusetts, United States of America.
David R
DR
Clarke
D011487:Protein Conformation; D017433:Protein Structure, Secondary; D011506:Proteins / Q000737:chemistry*
D011506:Proteins