Bartlett MD, Croll AB, King DR, Paret BM, Irschick DJ, Crosby AJ. (2012) Looking Beyond Fibrillar Features to Scale Gecko-Like Adhesion. Advanced Materials. 24:1078-1083. Published article.
Hand-sized gecko-inspired adhesives with reversible force capacities as high as 700 lbs (29.5 N cm-2) are designed without the use of fibrillar features through a simple scaling theory. The scaling theory describes both natural and synthetic gecko-inspired adhesives, over 14 orders of magnitude in adhesive force capacity, from nanoscopic to macroscopic length scales.
Bartlett MD, Croll AB, Crosby AJ. (2012) Designing Bio-Inspired Adhesives for Shear Loading: From Simple Structures to Complex Patterns. Advanced Functional Materials. 22:4985-4992. Published article.
To provide guidance for bio-inspired adhesives under shear, a simple scaling theory is used to investigate the relevant geometric and material parameters. The total compliance of an elastic attachment feature is described over many orders of magnitude in aspect ratio through a single continuous function using the superposition of multiple deformation modes such as bending, shear deformation, and tensile elongation. This allows for force capacity predictions of common geometric control parameters such as thickness, aspect ratio, and contact area.
Bartlett MD, Crosby AJ. (2013) Scaling Normal Adhesion Force Capacity with a Generalized Parameter. Langmuir. DOI: 10.1021/la4013526. Published article.
The adhesive response of a rigid flat cylindrical indenter in contact with a compliant elastic layer of varying confinement is investigated experimentally and described analytically. We discuss how the geometry of the contact, specifically increasing the degree of confinement, allows reversible adhesive materials to be designed that are not "sticky" or "tacky", yet can be very strong and provide high performance.
Bartlett MD, Crosby AJ. (2014) High Capacity, Easy Release Adhesives From Renewable Materials. Advanced Materials. DOI: 10.1002/adma.201305593 Published article.
Reversible adhesives composed of renewable materials are presented which achieve high force capacities (810 N) while maintaining easy release (∼0.25 N) and reusability. These simple, non-tacky adhesives consist of natural rubber impregnated into stiff natural fiber fabrics, including cotton, hemp, and jute. This versatile approach enables a clear method for designs of environmentally-responsible, reversible adhesives for a wide variety of applications.
King DR, Bartlett MD, Gilman CA, Irschick DJ, Crosby AJ. (2014) Creating Gecko-Like Adhesives for "Real World" Surfaces. Advanced Materials. DOI: 10.1002/adma.201306259 Published article.
Fabricated adhesives are demonstrated to support high loads while maintaining easy release on a variety of "real world" surfaces. These adhesives consist of simple elastomers and fabrics without nano or micron scale features, yet they surpass the adhesive force capacity of live Tokay geckos and can be scaled to large sizes.