Dissertation Defense: Bioinspired Surfaces Adapted from Shark Skin, Skimmer Birds, and Lotus Leaves for Low-drag and Superliquiphobic Properties

Samuel Martin, PhD Candidate, Mechanical Engineering

All dates for this event occur in the past.

E339 Scott Lab
E339 Scott Lab
201 W. 19th Ave.
Columbus, OH 43210
United States

Committee Members

  • Dr. Noriko Katsube, Chair (Mechanical Engineering)
  • Dr. Terrence Conlisk (Mechanical Engineering)
  • Dr. Anthony Luscher (Mechanical Engineering)



Abstract

Nature can be turned to for inspiration into novel engineering designs that help address scientific difficulties. Through evolution, nature has created efficient and multipurpose objects using commonly occurring materials. These objects have many applications that can aid humanity and can be of commercial interest. Two technical difficulties that nature can help solve include drag and liquid repellency. Inspiration for low-drag surfaces can be found on the skin of fast-swimming sharks and on the lower beaks of skimmer birds. Inspiration for extreme liquid repellency, also known as superliquiphobicity, can be found on lotus leaves (Nelumbo nucifera). The motivation for studying the surfaces of sharks, skimmer birds, and lotus leaves is that their unique surface features can be adapted for commercial applications to save time, money, and lives. Nature has a limited material toolbox, but by incorporating synthetic materials and better manufacturing processes, the surface properties can be enhanced. Mimicking these biological structures and using them for design inspirations is the field of biomimetics. In this work, original research on surfaces inspired by shark skin, skimmer birds, and lotus leaves is presented. Shark skin surfaces were created and analyzed using computational fluid dynamics (CFD) to characterize drag and fluid structures. Skimmer bird surfaces were created using a replica molding technique for flow cell testing as well as analyzed using CFD. Lotus leaf surfaces were created with several manufacturing methods including spray coating, vapor and spin coat deposition, and micropatterning. These surfaces were characterized for liquid repellency using contact angle and tilt angle with water and hexadecane and in some cases using shampoo and laundry detergent. This work provides discussion on optimal design as well as valuable insight for low-drag and superliquiphobic surfaces. The objective of studying these surfaces was to understand their underlying principles for improved surface design in low-drag and superliquiphobic applications. This design knowledge has applications in a wide variety of industries as surfaces with these properties continue to develop and the number of applications requiring these properties increase.