William Megill, Ph.D.
Biomechanics & Biomimetics Research
Biomechanics
- Jellyfish Biomechanics
- My PhD thesis research on the structure and dynamic behaviour of jellyfish mesoglea.
I measured the mechanical behaviour of jellyfish mesoglea, then developed a model of the
fibre-reinforced tissue to predict the behaviour of the mesogleal bell of the jellyfish.
This was then coupled with a model of the fluid flow around the animal which correctly
predicted the swimming frequency of jellyfish of all sizes. I am currently working on a
finite element model of the jellyfish to replace the analytical approximation I developed
in my thesis.
Publications
- Megill WM (2002) The
biomechanics of jellyfish swimming. PhD thesis, University of British Columbia.
- Megill WM (in review) Jellyfish biomechanics: The role of fibre-reinforcement
in the mechanical behaviour of a biological soft-tissue. ANZIAM Gazette.
- Megill WM, Gosline JM, Blake RW (in review) The modulus of elasticity of the
mesogleal microfibrils from the hydromedusan Polyorchis penicillatus. J. exp. Biol..
- Spider Web Design
- Research on the dynamic behaviour of spider webs in relation to their mechanical
properties. I am using a finite element model to study spider webs made by Golden Orb
Weavers. I am looking at the relationship between the mechanical properties of the
spiders' silk and the geometry of their webs.
- Mechanics of the caudal peduncle in grey whale swimming
- I am using an underwater camera and depthsounder to study the straight-line
swimming behaviour of grey whales. The animals will often swim parallel to a research
vessel, though usually too far away to be seen underwater. Using the depthsounder,
which is mounted horizontally on the hull of the research vessel, I hope to be able
to "see" the animals at about 50-100', and hence record the deflection of their
caudal peduncle as they swim. Field tests of the equipment are scheduled for next summer.
- Underwater swimming behaviour of grey whales
- We are quantifying the underwater manoeuvrability of grey whales in relation
to their prey and the bottom topography. We use suction-cup tags to record the
animals' pitch, roll and yaw, while simultaneously recording the depth. The animals
are tracked at the surface using shore-based theodolites. The depth and theodolite
data are combined to give a picture of the animals' underwater tracks. The body
orientation information is then superimposed on the tracks to develop a total
picture of the animals' underwater movements. The bottom topography and prey
distribution are mapped out using sonar equipment and scuba divers.
Collaborators
- Mick Peterson, Becky Woodward
Mechanical Engineering, UMaine
- Dynamic mechanical behaviour of the human breast
- I am using a finite element model to study the deformation of the human
breast during running. The model is based on 3-dimensional images of real people,
and makes use of literature values for the mechanical properties of the component
tissues of the breast and experimental measurements of the mechanical behaviour of
the bra fabric. The project is part of a larger study of sports bra design.
Biomimetics
- Robo-minnow
- A miniature autonomous underwater vehicle, propelled and controlled by
conducting polymer technology. The robot swims in a pseudo-tunniform mode
using a flexible foil propulsion system. Powered by watch batteries, it is
designed to be equipped with chemical and/or light sensors and scrubbers
for environmental polutant detection and clean-up.
- Biomimetic flagellum
- The idea with this project is to develop an autonomous vehicle which can
propel itself through very high viscosity fluids. Using conducting polymer actuators,
the robot is designed to mimic a biological flagellum, with its 9+2 construction. The
robot swims by contracting the actuators in the appropriate sequence to generate a
corkscrew motion in the propulsion unit. The robot is essentially a miniature
delivery system, powered by watch batteries, and designed to carry sensing
equipment into highly viscous environments such as animal guts or crude oil.