Abstract: Over the life of this grant, significant technical contributions have been made. When this grant commenced, we were at the very beginnings of building a hierarchical gecko-inspired adhesive. Since that point, we have developed hierarchical synthetic adhesive has been developed which utilizes milli/micro/nanofabrication to build active adhesive devices. In addition, in the final year of the grant, the adhesive was made actively reversible, and we were able (with additional funds from the ARMY UARC Institute for Collaborative Biotechnology) to realize the first bio-inspired REVERSIBLE adhesive, capable of sticking and unsticking with an integrated magnetic actuator. Geckos, as well as many insects, have evolved a robust reversible adhesion mechanism, enabling them to traverse rough, smooth, vertical or inverted surfaces. In this final report, we present a synthetic reversible adhesive composed of flexible nickel paddles coated by aligned vertical polymeric nanorods. When subjected to a magnetic field, the nickel paddles undergo a reversible conformational change, greatly reducing the contact area, and decreasing adhesion by a factor of 40. In addition, the ratio of adhesion force to pre-load force achieved was 1.5, which is over an order of magnitude greater than any other research results to date on gecko-inspired synthetic adhesives. In the final year of the project, we were able to make this device fully reversible, capable of unsticking due to the application of the magnetic field. This represents a large step in the development of such systems for many applications. Such controllable adhesion may impact technologies ranging from ubiquitous latching systems to high-tech applications such as microrobotics. Following the early results, we were able to utilize these results to obtain significant support from other branches of the department of Defense as well, broadening our goals.
| Limitations: |
APPROVED FOR PUBLIC RELEASE |
| Description: |
Final technical rept. 1 Jan 2005-30 Jun 2008 |
| Pages: |
16 |
| Report Date: |
10-Feb-2009 |
| Contract Number: |
FA9550-05-1-0045 FA95500510045 |
| Report Number: |
A063594 |
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