Microfibers with mushroom-shaped tips for optimal adhesion
AssigneeSetex Technologies, Inc.
InventorsMetin Sitti, Burak Aksak
Life of this patent
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Abstract
This invention identifies important geometric parameters of an adhesive microfiber with mushroom-shaped tip for improving and optimizing adhesive ability. The magnitude of pull-off stress is dependent on a wedge angle γ and the ratio of the tip radius to the stalk radius β of the mushroom-shaped fiber. Pull-off stress is also found to depend on a dimensionless parameter x, the ratio of the fiber radius to a length-scale related to the dominance of adhesive stress. Finally, the shape of edge tip, where the surface and sides of the mushroom-shaped tip join, is a factor that impacts strength of adhesion. Optimizing ranges for these parameters are identified.
Claims8
A dry adhesive fiber structure with optimized geometric parameters for increasing adhesive performance, comprising:
- a dry adhesive fiber comprising a moldable plastic, the dry adhesive fiber including:
- a mushroom-shaped tip having a flat surface with a radius at, inwardly inclined sides that form a wedge angle γ with the surface, a tip edge located at an outer perimeter of the tip, wherein the tip edge has an angle not equal to the wedge angle, and an end opposite the surface;
- and
- a stem with a cross-sectional area having (i) a distal end connected to the end of the tip at a tip point of connection, (ii) a proximal end opposite the distal end, and (iii) a longitudinal length with a radius a from the distal end to the proximal end;
- wherein the ratio of at/a is 1.05-1.4, wedge angle γ is 20-55, and the normalized pull-off stress at the fiber surface is 0.7-0.9.
Dependencies are inferred from the claim text.