Waterproof bandage with a sticky secret

London: Surgeons are preparing for the day they can repair their patients with a waterproof adhesive bandage that is inspired by the clingy feet of gecko lizards.

The team that devised the "gecko bandage" hope to start human trials within two years and believe that it may soon join sutures and staples as a basic operating room tool for doctors patching up surgical wounds or internal injuries. Each gecko foot is packed with about half a million fine hairs. The tip of each hair has thousands of projections, and can get so close to a surface that weak interactions between the surfaces become significant.

The interactions can add up to a strong attraction. While a single gecko hair, only one 100th the diameter of a human hair, could lift an ant, a million hairs could lift a child of about 45lb.

The surface of the bandage developed by a team led by Dr Jeff Karp and Prof Robert Langer at the Massachusetts Institute of Technology, Boston, has the same kind of microscopic hills and valleys that allow the lizards to cling to walls and ceilings.

Tests reveal that this doubled the adhesive bond. And because the bandage is biodegradable, it dissolves over time and so does not have to be removed.