Date of Award


Document Type

Open Access Master's Thesis

Degree Name

Master of Science in Materials Science and Engineering (MS)

Administrative Home Department

Department of Materials Science and Engineering

Advisor 1

Jaroslaw Drelich

Committee Member 1

Daniel Seguin

Committee Member 2

Jeremy Goldman


Some insects have the ability to walk on water surface due to hierarchical leg structure and wax coating. This work presents studies of water strider and fire ant leg immersion force profiles to measure resistance of legs to submersion and show orientation effects. A high-sensitivity microbalance measured force during immersion of insect legs at various angles into water droplets. Legs oriented parallel to water surface could support three to five times as much force before immersion, compared to legs in a perpendicular orientation. Water pressure affects the setae structure differently at parallel and perpendicular approaches, and complete wetting is more difficult in the structure observed during parallel approach. Once wetted, perpendicularly oriented legs experienced greater adhesion forces during retraction. Immersion and retraction force profiles were modelled as functions of leg dimensions and angle of approach, with strong correlation to experimental results. The hydrophobic wax coating on water strider legs was also found to decrease adhesion force with little effect on immersion force. Overall, strider legs that are oriented parallel to the water surface, coated in a mildly hydrophobic wax, and have coned setae with nanogrooves to facilitate removal of water, are excellent models for legs of a biomimetic aquatic robot.