Title:
Control of burial and subsurface locomotion in particulate substrates

dc.contributor.advisor Goldman, Daniel I.
dc.contributor.author Sharpe, Sarah S.
dc.contributor.committeeMember DeWeerth, Stephen P.
dc.contributor.committeeMember Nichols, Richard
dc.contributor.committeeMember Hu, David
dc.contributor.committeeMember Wiesenfeld, Kurt
dc.contributor.department Biomedical Engineering (Joint GT/Emory Department)
dc.date.accessioned 2014-01-13T16:49:21Z
dc.date.available 2014-01-13T16:49:21Z
dc.date.created 2013-12
dc.date.issued 2013-11-12
dc.date.submitted December 2013
dc.date.updated 2014-01-13T16:49:21Z
dc.description.abstract A diversity of animals move on and bury within dry and wet granular media, such as dry desert sand or rainforest soils. Little is known about the biomechanics and neural control strategies used to move within these complex terrains. Burial and subsurface locomotion provides a particularly interesting behavior in which to study principles of interaction because the entire body becomes surrounded by the granular environment. In this dissertation, we used three model organisms to elucidate control principles of movement within granular substrates: the sand-specialist sandfish lizard which dives into dry sand using limb-ground interactions, and swims subsurface using body undulations; the long-slender shovel-nosed snake which undulates subsurface in dry sand with low slip; and the ocellated skink, a desert generalist which buries into both wet and dry substrates. Using muscle activation measurements we discovered that the sandfish targeted optimal kinematics which maximized forward speed and minimized the mechanical cost of transport. The simplicity of the sandfish body and kinematics coupled with a fluid-like model of the granular media revealed the fundamental mechanism responsible for neuromechanical phase lags, a general timing phenomenon between muscle activation and curvature along the body that has been observed in all undulatory animals that move in a variety of environments. Kinematic experiments revealed that the snake moved subsurface using a similar locomotion strategy as the sandfish, but its long body and low skin friction enabled higher performance (lower slip). The ocellated skink used a different locomotor pattern than observed in the sandfish and snake but that was sufficient for burial into both wet and dry media. Furthermore, the ocellated skink could only reach shallow burial depths in wet compared to dry granular media. We attribute this difference to the higher resistance forces in wet media and hypothesize that the burial efficacy is force-limited. These studies reveal basic locomotor principles of burial and subsurface movement in granular media and demonstrate the impact of environmental interaction in locomotor behavior.
dc.description.degree Ph.D.
dc.format.mimetype application/pdf
dc.identifier.uri http://hdl.handle.net/1853/50345
dc.language.iso en_US
dc.publisher Georgia Institute of Technology
dc.subject Neuromechanics
dc.subject Granular media
dc.subject Subsurface locomotion
dc.subject.lcsh Locomotion
dc.subject.lcsh Animal locomotion
dc.subject.lcsh Biomechanics
dc.subject.lcsh Bulk solids flow
dc.subject.lcsh Bulk solids
dc.title Control of burial and subsurface locomotion in particulate substrates
dc.type Text
dc.type.genre Dissertation
dspace.entity.type Publication
local.contributor.advisor Goldman, Daniel I.
local.contributor.corporatename Wallace H. Coulter Department of Biomedical Engineering
local.contributor.corporatename College of Engineering
relation.isAdvisorOfPublication c4e864bd-2915-429f-a778-a6439e3ef775
relation.isOrgUnitOfPublication da59be3c-3d0a-41da-91b9-ebe2ecc83b66
relation.isOrgUnitOfPublication 7c022d60-21d5-497c-b552-95e489a06569
thesis.degree.level Doctoral
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