title: Twist and stretch of helices explained via the Kirchhoff-Love rod model of elastic filaments.
abstract: In various single-molecule experiments, a chiral polymer, such as DNA, is simultaneously pulled and twisted. We address an elementary but fundamental question raised by various authors: does the molecule overwind or unwind under tension? We show that within the context of the classic Kirchhoff-Love rod model of elastic filaments, both behaviors are possible, depending on the precise constitutive relations of the polymer. More generally, our analysis provides an effective linear response theory for helical structures that relates axial force and axial torque to axial translation and rotation.
authors.affiliation: Program in Applied Mathematics, University of Arizona, Tucson, Arizona AZ85721, USA.
authors.forename: Bojan
authors.initials: B
authors.lastname: Ðuričković
authors.affiliation: OCCAM, Mathematical Institute, University of Oxford, Oxford OX2 6GG, United Kingdom.
authors.forename: Alain
authors.initials: A
authors.lastname: Goriely
authors.affiliation: Section of Mathematics, Swiss Federal Institute of Technology (EPFL), Lausanne CH-1015, Switzerland.
authors.forename: John H
authors.initials: JH
authors.lastname: Maddocks