SUBJECT: Ph.D. Dissertation Defense
BY: Marguerite Matherne
TIME: Monday, May 3, 2021, 10:00 a.m.
PLACE:, Online
TITLE: Particle manipulation in nature: from honey bees to mammal tails
COMMITTEE: Dr. David Hu, Chair (ME)
Dr. Katherine Fu (ME)
Dr. Todd Sulchek (ME)
Dr. Jennifer Leavey (BIO)
Dr. Peter Yunker (PHYS)


A horse striking mosquitoes with its tail and a honeybee transporting pollen back to the hive are both examples of animals dealing with the particles that surround them. Understanding these processes can inspire new ways to manage granular materials in industry as well as repel biting insects from people and livestock. This thesis presents experiments elucidating the mechanics of pollen transport in honeybees and tail swinging by mammals. Honey bees carry pollen back to their hive by mixing it with nectar and forming it into a pellet, which they carry in the corbicula, or pollen basket, on their hind legs. The kinematics of the leg movement during the pellet removal process are measured and an apparatus is designed and built to measure the forces during pellet removal. The measured viscoelastic properties of the pellet explain how the honey bee is able to keep the pellet attached to its hind legs while flying. We perform rheological experiments with pollen suspensions showing that the suspension is an attractive yield stress fluid, and that pollenkit plays a minor role in the rheological properties of the pellet. In parallel work with tail-swinging in mammals, we report the measured kinematics of a mammal's tail swing, and perform experiments with a tail mimic that show how mammal tails act as aerodynamic shields to block biting insects. Throughout this thesis, efforts are made to test and build physical mimics to understand the strategies employed in nature.