Cantilever Peel Measurements on Patterned Surfaces: Characterizing the Effect of Pattern Geometry and Void Space.
John A. Howarter, Edwin Chan, Christopher Stafford
Microstructural and hierarchical patterns are able to enhance the fracture toughness of adhesive interfaces. This phenomenon has been observed naturally in the design of foot pads of insects and other small animals such as the gecko. By understanding the structural mechanisms responsible for enhanced fracture toughness, new design elements may become relevant when considering microstructure and texture at interfaces. Surfaces were patterned with varied amounts of surface area and void space occurring in regular patterns. By changing the void space, it is possible to manipulate the stress profile about the interface prior to crack initiation, thus altering the energy cost for delamination. We demonstrate that both parallel and perpendicular pattern spacing effectively disrupts delamination causing multiple initiation events. The periodicity of void space perpendicular to the crack front has a strong influence on the total amount of energy required for complete delamination. Geometric shape and orientation of the patterns was also varied thus creating anisotropic fracture behavior as a result of surface texture. Surfaces have been created thus far with up to a 40% reduction in load required to initiate delamination based on solely on changing the direction of crack propagation.
, Chan, E.
and Stafford, C.
Cantilever Peel Measurements on Patterned Surfaces: Characterizing the Effect of Pattern Geometry and Void Space., 33rd Annual Meeting of the Adhesion Society, Daytona Beach, FL, US, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=904852
(Accessed February 24, 2024)