Foot-ground interaction in granular media

Locomotor systems in animals respond to and manipulate unstable environments around them. These natural environments display complex behavior of both flowing and solidifying at different stages of a single step. I combine numerical modeling with laboratory experiments to study the interaction between a foot and its granular environment, in order to understand the role played by morphology and kinematics of foot use in locomotion on granular media.

particles splash

Circular disk intruding into granular medium.




Chemical sensing in aquatic invertebrates

Aquatic invertebrates use their sensory hairs to navigate the chemical landscape around them, and track the source of odorants to locate prey, predators and suitable habitat. They commonly use their antenna to “sniff” the dispersing adorants around them. I use numerical modeling to study the morphology of their olfactory appendages and the kinematics of their motion to understand the plume tracking mechanisms in aquatic animals.

References:
Pravin S. , Berger E., Mellon DeF. and Reidenbach M.A. (2015) Effects of sensilla morphology on mechanosensory sensitivity in the crayfish. Bioinspiration & Biomimetics, 10.3: 036006.
Pravin S., Mellon DeF., and Reidenbach M.A. (2012) Micro-scale fluid and odorant transport to antennules of the crayfish, Procambarus clarkii. Journal of Comparative Physiology A, 198(9): 669-681.

crayfish

Antennular flagellum of Procambarus clarkii.

crayfish

Concentration contours at the end of downstroke (a,c) and return stroke (b,d).




Turbulent plume characteristics

The odorant plumes found in benthic environments are disperse and filamentous in nature. I use a combination of particle image velocimetry, laser induced fluorescence and numerical modeling to examine the instantaneous nature of turbulent odorant plumes in the context of chemical sensing in aquatic animals.

References:
Pravin S., and Reidenbach M.A. (2013) Simultaneous sampling of flow and odorants by crustaceans can aid searches within a turbulent plume. Sensors, 13: 16591-16610.

crayfish

Turbulent odorant plume concentration.