Nature 546, 396–400 (2017)

How do you build an adhesive material that performs well underwater? Start by asking an octopus. Everyone's favourite cephalopod excels at using the adhesive power of the suckers on its tentacles to get around. Sangyul Baik and colleagues took inspiration from this design to fabricate a reversible adhesion system that works well in both wet and dry conditions. Their simulacrum even managed to heft a weight (here, a silicon wafer) through water and air — much like an octopus transporting its prey.

Baik et al. developed a technique involving a patterned silicon structure that they used as a master for their adhesive polymer-based material, which they then tested by sticking it to silicon wafers, glass and skin under varying degrees of moisture. They explained the material's remarkable underwater performance with a model combining suction and capillary stresses — and highlighting the role of geometry in optimizing cohesive forces. Success in the case of adhesion to pig skin indicates that the material may be applied to wound healing.