Letters: June 2018

Letters - Dr Jenkins illustration

Source: © Andrew Birch

You tell us about geckos, car brakes and suicide prevention

I read with great interest your report on a novel adhesive based on geckos (Chemistry World, March 2018, p43). However, there are inappropriate statements of key facts about history of gecko adhesion study and transistors. The report states that the discovery geckos use van der Waals forces to stick to walls via tiny hairs called setae on their toepads was made in 2012. In fact, the submicron spatula structures at the setal tips of geckos were revealed using electron microscopy in as early as 1965. Moreover, in 2002 researchers at Lewis and & Clark College, US, confirmed van der Waals forces as the primary molecular mechanism of gecko’s remarkable stickiness. The 2012 discovery was actually an invention: the team developed a powerful dry adhesive called Geckskin, which, composing of stiff fabrics and soft elastomers, was demonstrated to hold heavy objects like a flat TV display on a smooth wall and could be removed easily with no residue.