Publications

Colloidal robotics

Nature Materials (2024)

Robot swarms meet soft matter physics

Science Robotics (2024)

Advances in Modeling Dense Granular Media

Annual Review of Fluid Mechanics (2024)

Physics of smart active matter: integrating active matter and control to gain insights into living systems

Soft Matter, Royal Society of Chemistry (2023)

Committee on Biological Physics/Physics of Living Systems: A Decadal Survey

The National Academies of Sciences, Engineering, Medicine (2022)

Bio-inspired geotechnical engineering: principles, current work, opportunities and challenges,

Géotechnique (2021)

Surprising simplicities and syntheses in limbless self-propulsion in sand,

Journal of Experimental Biology (2020), 223 (5):

Physics approaches to natural locomotion: Every robot is an experiment,

Chapter 6: Robotic Systems and Autonomous Platforms, 1st Edition, Advances in Materials and Manufacturing (2018)

A review on locomotion robophysics: the study of movement at the intersection of robotics, soft matter, and dynamical systems,

Reports on Progress in Physics 79 110001 (2016)

Entangled Granular Media,

Fluids, Colloids and Soft Materials: An Introduction to Soft Matter Physics, (2016)

Beneath our feet: strategies for locomotion in granular media,

Annual Review of Fluid Mechanics, 47, 431-453 (2015)

Colloquium: Biophysical principles of undulatory self-propulsion in granular media,

Reviews of Modern Physics, 86, 943 (2014)

The effectiveness of resistive force theory in granular locomotion,

Physics of Fluids, 26, 101308 (2014)

Swimming in the desert,

Physics Today, November, pg. 68 (2013)

Comparative studies reveal principles of movement on and within granular media,

IMA Workshop on Locomotion (2011)

Wiggling Through the World,

American Scientist, July/August 2010

March of the SandBots,

IEEE Spectrum, April 2009, pg. 30.

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Probing Hydrodynamic Fluctuation-Induced Forces with an Oscillating Robot

Physical Review Letters 132, 084001 (2024)

Anisotropic body compliance facilitates robotic sidewinding in complex environments

arXiv(2023):2309.13532.

Learning manipulation of steep granular slopes for fast Mini Rover turning

arXiv(2023):2310.01273.

The rhizodynamics robot: Automated imaging system for studying long-term dynamic root growth,

PLOS ONE 18(12) (2023): e0295823.

Mechanical intelligence simplifies control in terrestrial limbless locomotion,

Science Robotics 8, eadi2243(2023).

A robophysical model of spacetime dynamics,

Scientific Reports 13, 21589 (2023).

Optimizing contact patterns for robot locomotion via geometric mechanics,

The International Journal of Robotics Research 42 (10), 859-873, 2023

Gait design for limbless obstacle aided locomotion using geometric mechanics,

Robotics, Science and Systems 2023, 10 July 2023

Toward a 3D physical model of diffusive polymer chains,

Frontiers in Physics, 29 June 2023

Agitated ants: regulation and self-organization of incipient nest excavation via collisional cues,

J. R. Soc Interface 20: 2022057 (2023)

Multilegged matter transport: A framework for locomotion on noisy landscapes,

Science (2023), Vol 380, Issue 6644, pp. 509-515

Self-propulsion via slipping: Frictional swimming in multilegged locomotors,

Proceedings of the National Academy of Sciences (PNAS) (2023)

Active and passive mechanics for rugose terrain traversal in centipedes,

Journal of Experimental Biology (JEB) (2023),Volume 226, No. 4, jeb244688

Amorphous entangled active matter,

Soft Matter, 2023, 19, 1952-1965

Mechanistic framework for reduced-order models in soft materials: Application to three-dimensional granular intrusion,

Proceedings of the National Academy of Sciences (PNAS) (2023), e2214017120

Simulation of compound anchor intrusion in dry sand by a hybrid FEM+SPH method,

Advanced Intelligence Systems (2022), 2200119

Real-Time Remodeling of Granular Terrain for Robot Locomotion,

Advanced Intelligence Systems (2022), 2200119

Robotic swimming in curved space via geometric phase,

Proceedings of the National Academy of Sciences (PNAS) (2022), Vol. 119, No. 31, e2200924119

Field-mediated locomotor dynamics on highly deformable surfaces,

Proceedings of the National Academy of Sciences (PNAS) (2022), Vol. 119, No. 30, e2113912119

A general locomotion control framework for multi-legged locomotors,

Bioinspiration and Biomimetics (2022), Vol. 17, 046015

Coordinating tiny limbs and long bodies: Geometric mechanics of lizard terrestrial swimming,

Proceedings of the National Academy of Sciences (PNAS) (2022), Vol. 119, No. 27, e2118456119

Oxygenation-Controlled Collective Dynamics in Aquatic Worm Blobs,

Integrative and Comparative Biology (2022), icac089

Toward Task Capable Active Matter: Learning to Avoid Clogging in Confined Collectives via Collisions,

Frontiers(2022), Volume 10, No. 725667

Robots as models of evolving systems,

Proceedings of the National Academy of Sciences (PNAS) of the United States of America (2022), Volume 119, No. 12

Construction and Excavation by Collaborative Double-Tailed SAW Robots,

IEEE Robotics and Automation Letters (2022), Volume 7, No. 2

Air-Fluidized Aggregates of Black Soldier fly Larvae,

Frontiers in Physics (2021), Volume 9, Article 734447

Lateral bending and buckling aids biological and robotic earthworm anchoring and locomotion,

Bioinspiration and Biomimetics (2021), Volume 17, Article 016001

Emergent Collective Locomotion in an Active Polymer Model of Entangled Worm Blobs,

Frontiers in Physics (2021), Volume 9, Article 734499

Frequency modulation of body waves to improve performance of sidewinding robots,

International Journal of Robotics Research (IJRR) (2021), 2783649211037715

Coordination of lateral body bending and leg movements for sprawled posture quadrupedal locomotion,

International Journal of Robotics Research (IJRR) (2021), Volume 40, Number 4-5, pages 747-763.

Enhancing Legged Robot Navigation of Rough Terrain via Tail Tapping,

Climbing and Walking Robots Conference (2021), pages 213-225

A minimal robophysical model of quadriflagellate self-propulsion,

Bioinspiration and Biomimetics (2021), Volume 16, Number 6, 066001

Effect of two parallel intruders on total work during granular penetrations,

Physical Review E (2021), Volume 104, Number 2, 024902

Self-reconfigurable multilegged robot swarms collectively accomplish challenging terradynamic tasks,

Science Robotics (2021), Volume 6, Number 56, eabf1628

Moving sidewinding forward: optimizing contact patterns for limbless robots via geometric mechanics,

Robotics: Science and Systems (2021)

Efficacy of simple continuum models for diverse granular intrusions,

Soft Matter (2021), Volume 17, pages 7196-7209

Controlling subterranean forces enables a fast, steerable, burrowing soft robot

Science Robotics: Volume 6, Issue 55, eabe2922

Surprising simplicity in the modeling of dynamic granular intrusion

Science Advances (2021), Volume 7, Number 17, eabe0631

Programming Active Cohesive Granular Matter with Mechanically Induced Phase Changes

Science Advances (2021), Volume 7, Number 17, eabe8494

Emergent Field-Driven Robot Swarm States

Physical Review Letters (2021), Volume 126, Number 10, 108002

Mechanism and function of root circumnutation

Proceedings of the National Academy of Sciences (PNAS) of the United States of America (2021), Volume 188, Number 8, e2018940118

Collective dynamics in entangled worm and robot blobs

Proceedings of the National Academy of Sciences (PNAS) of the United States of America (2021), Volume 118, Number 6, e2010542118

Functional consequences of convergently evolved microscopic skin features on snake locomotion

Proceedings of the National Academy of Sciences (PNAS) of the United States of America (2021), Volume 118, Number 6, e2018264118

Low rattling: A predictive principle for self-organization in active collectives

Science (2021), Volume 371, Issue 6524, pages 90-95

Frequency Modulation of Body Waves to Improve Performance of Limbless Robots

Robots: Science and Systems 2020

The Omega Turn: A Biologically-Inspired Turning Strategy for Elongated Limbless Robots

2020 International Conference on Intelligent Robots and Systems (IROS), pages 7766-7771

Optimizing coordinate choice for locomotion systems with toroidal shape spaces

2020 International Conference on Intelligent Robots and Systems (IROS), pages 7501-7506

Robophysical modeling of bilaterally activated and soft limbless locomotors,

Living Machines (2020), pages 300-311

Stretchable Nanocomposite Sensors, Nanomembrane Interconnectors, and Wireless Electronics toward Feedback−Loop Control of a Soft Earthworm Robot,

ACS Applied Materials and Interfaces (2020), Volume 12, Number 39, pages 43388-43397

Comparative study of snake lateral undulation kinematics in model heterogeneous terrain,

Integrative and Comparative Biology (2020), Volume 63, Issue 1, July 2023, Pages 198–208, https://doi.org/10.1093/icb/icaa125

Side-impact collision: mechanics of obstacle negotiation in sidewinding snakes,

Bioinspiration and Biomimetics (2020), Volume 15, Number 6, 065005

Learning Terrain Dynamics: A Gaussian Process Modeling and Optimal Control Adaptation Framework Applied to Robotic Jumping,

IEEE Transactions on Control Systems Technology,

A systematic approach to creating terrain-capable hybrid soft/hard myriapod robots,

2020 3rd IEEE International Conference on Soft Robotics (RoboSoft), pages 156-163

Mitigating memory effects during undulatory locomotion on hysteretic materials,

eLife Sciences (2020), Volume 9, e51412

Material remodeling and unconventional gaits facilitate locomotion of a robophysical rover over granular terrain,

Science Robotics (2020), Volume 5, Issue 42, eaba3499

Modeling of the interaction of rigid wheels with dry granular media,

Journal of Terramechanics (2019), Volume 85, pages 1-14

A robot made of robots: Emergent transport and control of a smarticle ensemble,

Science Robotics (2019), Volume 4, Issue 34

A Hierarchical Geometric Framework to Design Locomotive Gaits for Highly Articulated Robots,

Robotics: Science and Systems · A Robotics Conference (RSS 2019), Freiburg, Europe.

Kirigami Skin Improves Soft Earthworm Robot Anchoring and Locomotion Under Cohesive Soil,

IEEE International Conference on Soft Robotics (RoboSoft),Seoul, Korea, April 14~18, 2019.

Nutation Aids Heterogeneous Substrate Exploration in a Robophysical Root,

IEEE International Conference on Soft Robotics (RoboSoft),Seoul, Korea, April 14~18, 2019.

Mechanical diffraction reveals the role of passive dynamics in a slithering snake,

PNAS (2019), 201808675.

Dynamics of scattering in undulatory active collisions,

Physical Review E (2019) Volume 99, Issue 2, 022606.

Bipedal Locomotion Up Sandy Slopes: Systematic Experiments Using Zero Moment Point Methods,

IEEE-RAS International Conference on Humanoid Robots (Humanoids) (2018).

Phototactic Supersmarticles,

Artificial Life and Robotics (2018) Volume 23, Issue 4, pp 459–468.

Collective clog control: Optimizing traffic flow in confined biological and robophysical excavation,

Science (2018) Volume 361, Issue 6403, pp. 672-677.

Coordination of back bending and leg movements for quadrupedal locomotion,

Robotics: Science and Systems (RSS) (2018)

Soft Robotic Burrowing Device with Tip-Extension and Granular Fluidization,

IROS (2018), pp. 5918-5923

Design of a Soft Robophysical Earthworm Model,

IEEE-RAS International Conference on Soft Robotics (RoboSoft) (2018)

Locomoting robots composed of immobile robots,

Second IEEE International Conference on Robotic Computing (IRC) (2018) pp. 224-227

Collisional Diffraction Emerges from Simple Control of Limbless Locomotion,

Conference on Biomimetic and Biohybrid Systems (611-618), Springer (2017)

A Stability Region Criterion for Flat-footed Bipedal Walking on Deformable Granular Terrain,

IEEE International Conference on Intelligent Robots and Systems (IROS) (2017)

Geometric Mechanics Applied to Tetrapod Locomotion on Granular Media,

Conference on Biomimetic and Biohybrid Systems (595-603), Springer (2017)

X-ray computed tomography reveals the response of root system architecture to soil texture,

Plant Physiology (2016)

Tractable Terrain-aware Motion Planning on Granular Media: An Impulsive Jumping Study,

IEEE International Conference on Intelligent Robots and Systems (IROS) (2016)

Shape-Based Compliance in Locomotion,

Robotics: Science & Systems (RSS) (2016)

Robophysical Study of Excavation in the Confined Environments,

Artificial Life and Robotics, 21, 460-465 (2016)

Awarded best paper at SWARM 2015

Simplifying Gait Design via Shape Basis Optimization,

Robotics: Science & Systems (RSS) (2016).

Tail use improves soft substrate performance in models of early vertebrate land locomotors,

Science, 353, 154-158, (2016)

Geometric Swimming on a Granular Surface,

Robotics: Science & Systems (RSS) (2016)

Robophysical study of jumping dynamics on granular media,

Nature Physics, 12, 278-283 (2016).

Glass-like dynamics in confined and congested ant traffic,

Soft Matter, 11, 6552-6561 (2015).

Behavioral and mechanical determinants of collective subsurface nest excavation,

J. Exp. Biol. 218, 1295-1305 (2015).

Modulation of orthogonal body waves enables high maneuverability in sidewinding locomotion,

PNAS, 112, 6200 (2015).

Smarticles: design and construction of smart particles to aid discovery of principles of smart, active granular matter,

SWARM 2015 conference paper (2015)

Locomotor benefits of being a slender and slick sand-swimmer,

Journal of Experimental Biology, 218, 440-450 (2015)

Controlled preparation of wet granular media reveals limits to lizard burial ability,

Physical Biology, 12, 046009 (2015)

Principles of appendage design in robots and animals determining terradynamic performance on flowable ground,

Bioinspiration & Biomimetics (2015).

Kinematic gait synthesis for snake robots,

IJRR (2015).

Anticipatory control using substrate manipulation enables trajectory control of legged locomotion on heterogeneous granular media,

SPIE (2015).

The dynamics of legged locomotion in heterogeneous terrain: universal scattering and sensitivity to initial conditions,

Robotics: Science & Systems (RSS) (2015).

Sidewinding with minimal slip: snake and robot ascent of sandy slopes,

Science, 346, 224 (2014)

The effect of volume fraction on granular avalanche dynamics,

Physical Review E, 90, 032202 (2014)

Force and flow at the onset of drag in plowed granular media,

Physical Review E, 89, 042202 (2014)

Conditioned basis array factorization: an approach to gait pattern extraction,

RSS (2014)

Swimming in the desert,

Physics Today, November, pg. 68 (2013)

Emergence of the advancing neuromechanical phase lag in a resistive force dominated medium,

PNAS, 110, 10123-10128 (2013)

Climbing, falling and jamming during ant locomotion in confined environments,

PNAS, 110, 9746-9751 (2013)

A terradynamics of legged locomotion on granular media,

Science, 339, 1408 (2013)

Geometric visualization of self-propulsion in a complex medium

Physical Review Letters 110, 078101 (2013)

Flipper driven terrestrial locomotion of a sea turtle inspired robot,

Bioinspiration & Biomimetics, 8, 026007 (2013)

Ground fluidization promotes rapid running of a lightweight robot,

International Journal of Robotics Research, 32, 859 (2013)

An automated system for systematic testing of locomotion on heterogeneous granular media,

CLAWAR (2013)

Environmental interaction influences muscle activation strategy during sand-swimming in the sandfish lizard (Scincus scincus)

Journal of Experimental Biology, 216, 260 (2012)

Mechanics of undulatory swimming in a frictional fluid,

PLoS Computational Biology, 8(12): e1002810 (2012)

Lift-off dynamics in a simple jumping robot,

Physical Review Letters, 109, 174301 (2012)

Entangled granular media,

Physical Review Letters, 108, 208001 (2012)

Effects of worker size on the dynamics of fire ant tunnel construction,

Journal of the Royal Society Interface, 9, 3312 (2012)

Multi-functional foot use during running of the zebra-tailed lizard (Callisaurus draconoides)

Journal of Experimental Biology, 215, 3293, (2012)

Walking and running on yielding and fluidizing ground,

Robotics: Science and Systems (RSS) conference (2012)

Using computational and mechanical models to study animal locomotion,

Integrative and Comparative Biology, 52, 553 (2012)

Geometric mechanics for sand swimming,

CLAWAR (2012)

A resistive force model for legged locomotion on granular media,

CLAWAR (2012)

Towards a terramechanics for bio-inspired locomotion in granular environments,

ASCE, Earth and Space 2012 conference (2012).

Mechanical models of sandfish locomotion reveal principles of high performance subsurface sand-swimming,

Journal of the Royal Society Interface, 8, 1332-1345 (2011)

Drag induced lift in granular media,

Physical Review Letters, 106, 028001 (2011)

Granular lift forces predict vertical motion of a sand-swimming robot,

ICRA, (2011)

Undulatory swimming in sand: experimental and simulation studies of a robotic sandfish,

International Journal of Robotic Research, 30, 793-805 (2011)

Force and flow transition in plowed granular media

Physical Review Letters, 105, 128301 (2010)

Granular impact and the critical packing state,

PRE Rapid Communications, 82, 010301R, (2010)

Wiggling Through the World,

American Scientist, July/August 2010

Biophysically inspired development of a sand-swimming robot,

Robotics: Science & Systems (RSS) 2010

Utilization of granular solidification during terrestrial locomotion of hatchling sea turtles,

Biology Letters,6,398,(2010)

The effect of limb kinematics on the speed of a legged robot on granular media,

Experimental Mechanics, 50, 1383 (2010)

Systematic study of the performance of small robots on controlled laboratory substrates,

Proceedings of SPIE, 7679, 76790Z, (2010)

Undulatory swimming in sand: subsurface locomotion of the sandfish lizard,

Science, 325, 314 (2009)

Sensitive dependence of the motion of a legged robot on granular media,

PNAS, 106, 3029, (2009)

March of the SandBots,

IEEE Spectrum, April 2009, pg. 30.

Integrating a Hierarchy of Simulation Tools for Legged Robot Locomotion,

IROS 2008

Scaling and Dynamics of Sphere and Disk Impact into Granular Media,

PRE, 77, 021308 (2008)

Active Tails Enhance Arboreal Acrobatics in Geckos,

PNAS, 105, 4215 (2008)

Design of a Bio-inspired Dynamical Vertical Climbing Robot,

Proceedings of Robotics: Science and Systems (2007)

Distributed mechanical feedback in arthropods and robots simplifies control of rapid running on challenging terrain

Bioinspiration and Biomimetics, 2 9-18 (2007)

Toward a dynamic climbing robot,

submitted to CLAWAR 2006, 9th International Conference on Climbing and Walking Robots

Dynamics of rapid vertical climbing in a cockroach reveals a template,

The Journal of Experimental Biology, 209, 2990-3000 (2006)

Signatures of glass formation in a fluidized bed of hard spheres,

PRL 96, 145702 (2006).

Low density fragile states in cohesive powders,

American Journal of Physics, 74, 720-721 (2006)

The RiSE Climbing Robot: Body and Leg Design,

Unmanned Systems Technology VIII, SPIE, 6230, 623017 (2006)

Robotics in Scansorial Environments,

Unmanned Ground Vehicle Technology VII, eds. Grant R. Gerhart, Charles M. Shoemaker, Douglas W. Gage, Proceedings of SPIE Vol. 5804, 291-302 (2005).

Stationary state volume fluctuations in a granular medium,

PRE Rapid Communications 71, 030301 (2005).

Noise, coherent fluctuations, and the onset of order in an oscillated granular fluid,

PRL 92, 174302 (2004).

Mach cone in a shallow granularfluid,

PRE Rapid Communications 70, 060301 (2004).

Crucial role of sidewalls in velocity distributions in quasi-2D granular gases,

PRE Rapid Communications 70, 040301 (2004).

Persistent holes in a fluid,

PRL 92, 184501 (2004)

Dynamics of drag and force distributions for projectile impact in a granular medium,

PRL 92, 194301 (2004).

Stages of relaxation of patterns and the role of stochasticity on the final stage,

Nonlinearity 17, 1535 (2004).

Lattice dynamics and melting of a nonequilibrium pattern,

PRL 90, 104302 (2003).

Kink-induced transport and segregation in oscillated granular layers,

PRL 91, 134301 (2003).

Emergence of order in an oscillated granular layer,

Physica A 306,180 (2002).

Phase bubbles and spatiotemporal chaos in granular patterns,

PRE 65, 011301 (2002).

Absence of inelastic collapse in a realistic three ball model

PRE 57, 4831 (1998)

Continuum-type stability balloon in oscillated granular layers,

PRL 81, 1421 (1998).

Simplifying Robotic Locomotion by Escaping Traps via an Active Tail,

Mechanical Engineering Masters Dissertation, Georgia Institute of Technology, 2022.

Geometric Modeling of Biological and Robotic Locomotion in Highly Damped Environments,

Quantitative Biosciences PhD Dissertation, Georgia Institute of Technology, 2022.

Non-Inertial Undulatory Locomotion Across Scales,

Quantitative Biosciences PhD Dissertation, Georgia Institute of Technology, 2022.

Rate-dependent Locomotion and Intrusion Phenomena in Granular Media,

Physics PhD Dissertation, Georgia Institute of Technology, 2022.

Field-Mediated Interaction in Active Matter,

Physics PhD Dissertation, Georgia Institute of Technology, 2022.

Limbless Locomotion in Complex Terrestrial Terrain,

Physics PhD Dissertation, Georgia Institute of Technology, 2019.

Effect of Shape and Particle Coordination on Collective Dynamics of Granular Matter,

Physics PhD Dissertation, Georgia Institute of Technology, 2019.

Developing an Anticipatory Controller to Imrove Performance of a Snake-like Robot in Unstructured Terrain,

Mechanical Engineering Masters Dissertation, Georgia Institute of Technology, 2018.

Design of Robotic Platforms to Model Confined Active Matters,

Mechanical Engineering Masters Dissertation, Georgia Institute of Technology, 2017.

Probing the Dynamics of a Simple Jumping Robot on Hard and Soft Ground,

Mechanical Engineering PhD Dissertation, Georgia Institute of Technology, 2016.

A Robophysics Approach to Bipedal Walking in Granular Media,

Physics PhD Dissertation, Georgia Institute of Technology, 2016.

Modeling and Control of Locomotion in Complex Environments,

Physics PhD Dissertation, Georgia Institute of Technology, 2016.

Towards a Terradynamics of Legged Locomotion on Homogenous and Heterogeneous Granular Media Through Robophysical Approaches,

Electrical and Computer Engineering PhD Dissertation, Georgia Institute of Technology, 2015.

Design of a Robotic Ant to Model Collective Excavation,

Mechanical Engineering Masters Dissertation, Georgia Institute of Technology, 2015.

Control of Burial and Subsurface Locomotion In Particulate Substrates,

Bioengineering PhD Dissertation, Georgia Institute of Technology, 2013.

Collective Dynamics Of Matter With Granularity,

Physics PhD Dissertation, Georgia Institute of Technology, 2013.

Exploring Lift-Off Dynamics In a Jumping Robot,

Master of Science in Mechanical Engineering Dissertation, Georgia Institute of Technology, 2012.

Principles Of Fin and Flipper Locomotion On Granular Media,

Biology Masters Dissertation, Georgia Institute of Technology, 2012.

Biological, Robotic, and Physics Studies to Discover Principles of Legged Locomotion on Granular Media,

Physics PhD Dissertation, Georgia Institute of Technology, 2011.

Simulation and Theoretical Study of Swimming and Resistive Forces Within Granular Media,

Physics PhD Dissertation, Georgia Institute of Technology, 2011.

Biological, Simulation, and Robotic Studies to Discover Principles of Swimming Within Granular Media,

Bioengineering PhD Dissertation, Georgia Institute of Technology, 2010.

Pattern formation and fluidization in vibrated granular layers, and grain dynamics and jamming in a water fluidized bed,

PhD Dissertation, The University of Texas at Austin, 2002.

Publications

CRAB Lab

Complex Rheology And Biomechanics