Forceless Sadowsky strips are spherical

E.L. Starostin & G.H.M. van der Heijden

We show that thin rectangular ribbons, defined as energy-minimizing configurations of the Sadowsky functional for narrow developable elastic strips, have a propensity to form spherical shapes in the sense that forceless solutions lie on a sphere. This has implications for ribbonlike objects in (bio)polymer physics and nanoscience that cannot be described by the classical wormlike chain model. A wider class of functionals with this property is identified.

keywords: elastic strip, one-dimensional variational problem, Sadowsky functional, equilibrium equations, spherical curves, bio- and nanofilaments

Physical Review E 97, 023001 (2018)