title: Sidewinding with minimal slip: snake and robot ascent of sandy slopes.
abstract: Limbless organisms such as snakes can navigate nearly all terrain. In particular, desert-dwelling sidewinder rattlesnakes (Crotalus cerastes) operate effectively on inclined granular media (such as sand dunes) that induce failure in field-tested limbless robots through slipping and pitching. Our laboratory experiments reveal that as granular incline angle increases, sidewinder rattlesnakes increase the length of their body in contact with the sand. Implementing this strategy in a physical robot model of the snake enables the device to ascend sandy slopes close to the angle of maximum slope stability. Plate drag experiments demonstrate that granular yield stresses decrease with increasing incline angle. Together, these three approaches demonstrate how sidewinding with contact-length control mitigates failure on granular media.
authors.affiliation: School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA, USA. School of Physics, Georgia Institute of Technology, Atlanta, GA, USA.
authors.forename: Hamidreza
authors.initials: H
authors.lastname: Marvi
authors.affiliation: Robotics Institute, Carnegie Mellon University, Pittsburgh, PA, USA.
authors.forename: Chaohui
authors.initials: C
authors.lastname: Gong
authors.affiliation: School of Physics, Georgia Institute of Technology, Atlanta, GA, USA.
authors.forename: Nick
authors.initials: N
authors.lastname: Gravish
authors.affiliation: School of Physics, Georgia Institute of Technology, Atlanta, GA, USA.
authors.forename: Henry
authors.initials: H
authors.lastname: Astley
authors.affiliation: Robotics Institute, Carnegie Mellon University, Pittsburgh, PA, USA.
authors.forename: Matthew
authors.initials: M
authors.lastname: Travers
authors.affiliation: School of Mechanical, Industrial, and Manufacturing Engineering, Oregon State University, Corvallis, OR, USA.
authors.forename: Ross L
authors.initials: RL
authors.lastname: Hatton
authors.affiliation: School of Biology, Georgia Institute of Technology, Atlanta, GA, USA. Department of Herpetology, Zoo Atlanta, Atlanta, GA, USA.
authors.forename: Joseph R
authors.initials: JR
authors.lastname: Mendelson
authors.affiliation: Robotics Institute, Carnegie Mellon University, Pittsburgh, PA, USA.
authors.forename: Howie
authors.initials: H
authors.lastname: Choset
authors.affiliation: School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA, USA. School of Physics, Georgia Institute of Technology, Atlanta, GA, USA. School of Biology, Georgia Institute of Technology, Atlanta, GA, USA.
authors.forename: David L
authors.initials: DL
authors.lastname: Hu
authors.affiliation: School of Physics, Georgia Institute of Technology, Atlanta, GA, USA. daniel.goldman@physics.gatech.edu.
authors.forename: Daniel I
authors.initials: DI
authors.lastname: Goldman
mesh_terms: D000818:Animals; D049628:Body Size; D017839:Crotalus / Q000033:anatomy & histology* / Q000502:physiology*; D008124:Locomotion; D012371:Robotics / Q000295:instrumentation*; D012822:Silicon Dioxide; D013499:Surface Properties
chemical_list: D012822:Silicon Dioxide