Shapes of a Suspended Curly Hair

Condensed Matter journal club

Shapes of a Suspended Curly Hair

  • Event time: 11:30am
  • Event date: 11th April 2014
  • Speaker: Alexander McVey (Formerly School of Physics & Astronomy, University of Edinburgh)
  • Location: Room 2511,

Event details


We investigate how natural curvature affects the configuration of a thin elastic rod suspended under its own weight, as when a single strand of hair hangs under gravity. We combine precision desktop experiments, numerics, and theoretical analysis to explore the equilibrium shapes set by the coupled effects of elasticity, natural curvature, nonlinear geometry, and gravity. A phase diagram is constructed in terms of the control parameters of the system, namely the dimensionless curvature and weight, where we identify three distinct regions: planar curls, localized helices, and global helices. We analyze the stability of planar configurations, and describe the localization of helical patterns for long rods, near their free end. The observed shapes and their associated phase boundaries are then rationalized based on the underlying physical ingredients.
PRL 112 article 068103 (2014)
pdf version


J. T. Miller, A. Lazarus, B. Audoly, P. M. Reis