Biologically Inspired Adhesive Microstructure

Bio-inspired adhesives are under development which employ nanofibrillar structures for reliable and strong adhesion to various substrates. Applications toward micro air vehicle locomotion and in broader dry adhesives markets are emphasized. Biological adhesives (employed by gecko, spider, etc.) rely on multi-scale structures with nanofibrillar contact elements for effective adhesion to rough or smooth surfaces of diverse materials. The nanofibrillar structure enables reliable achievement of high adhesion capacity despite surface flaws and variable contact angles. The nano-scale structure also lowers the required preload pressure, offers stability under high-amplitude fatigue, and provides inherent self-cleaning capabilities. The multi-scale structure of biological adhesives allows them accommodate the surface roughness and assume different configurations favoring strong attachment and convenient detachment. The Phase I research is implementing an integrated theoretical/experimental research program, which has so far led to: (i) comprehensive theoretical modeling of bio-inspired adhesion mechanisms; (ii) development of alternative processing techniques for production of bio-inspired adhesives; and (iii) production and experimental evaluation of progressively refined bio-inspired adhesive systems. The proposed Phase II project will build upon the theoretical and experimental accomplishments of Phase I research toward: (i) refinement, expansion and integration of the theoretical models and design methodologies; (ii) further development of processing techniques for efficient production of more complex and versatile nanofibrillar structures; (iii) design and production of bio-inspired adhesives, and thorough characterization of their adhesion, self-cleaning, detachment and long-term durability attributes; (iv) development of mechanisms embodying bio-inspired adhesives for effective attachment and convenient detachment, and their incorporation into novel micro air vehicle locomotion systems; (vii) tailoring of bio-inspired adhesion mechanisms toward broader markets for dry, pressure-sensitive adhesives; and (viii) competitive market analysis of the technology. The thorough understanding of the biological adhesion mechanisms realized in Phase I research together with the strong reliance on sound theoretical principles, effective use of recent advances in nanotechnology, and close collaboration with major suppliers and end-users have been key to the success of Phase I research, and will be further emphasized in Phase II project toward full development and market transition of the technology.