Inspired by the hairs that allow geckos to hang single-toed from sheer walls and scamper along ceilings, a team of researchers led by engineers at the University of California, Berkeley, has created an array of synthetic microfibres that uses very high friction to support loads on smooth surfaces.

High friction materials can prevent sliding under high loads or steep inclines. The researchers found that the synthetic array of polypropylene fibres could hold a coin to a glass slide inclined at an 80 degree angle, yet is not ’sticky’ like adhesive tape. The fibres, packed 42 million per square centimetre, each measure just 20 microns long and 0.6 microns in diameter, about 100 times thinner than a human hair.

High friction and low adhesion are desirable traits for products such as footwear soles, car tyres and a variety of athletic equipment. Soft materials such as rubber are now used for these products, but the researchers note that a stiff polymer could possibly stand up to higher temperatures and wear better than such materials.