Effect of Elasticity on Liquid Repellency of Cassie-State Droplets on Superhydrophobic Surfaces

Open Access
Author:
Feldstein, Hannah
Area of Honors:
Mechanical Engineering
Degree:
Bachelor of Science
Document Type:
Thesis
Thesis Supervisors:
  • Tak-Sing Wong, Thesis Supervisor
  • Hosam Fathy, Honors Advisor
Keywords:
  • superhydrophobic surface
  • bio-inspired
  • liquid repellency
  • pdms
  • microstructure
Abstract:
Many natural surfaces contain microstructures that are used to repel liquid. However, the effects of elasticity on liquid repellency have not been thoroughly investigated. A polydimethylsiloxane (PDMS) molding process was used to create microstructured superhydrophobic surfaces of varying elasticities and geometries. These surfaces were characterized using a sliding angle test in order to measure their liquid repellency. Overall, the results show that increasing the solid fraction results in poorer liquid repellency, for elasticities ranging from 1.18 MPa to 2.86 MPa. Additionally, some results suggest that increasing the Young’s modulus of the micropillars also results in a higher degree of pinning due to a greater amount of energy consumed by pillar deformation.