A flexible electronic sensor made from interlocking hairs can detect the gentle steps of a ladybird and distinguish between shear and twisting forces, just as human skin can. It can also be strapped to the wrist and used as a heart-rate monitor.
The described device was inspired by beetle wings and could give robots a more nuanced sense of touch. When some beetles are resting, a row of hairs on their wings locks into an array of hairs on their body through a type of static attraction called van der Waals' forces. In Suh’s sensors, the 'hairs' are sheets of polymer fibres that are 100 nanometres in diameter and one micrometre long, and coated with metal to make them electrically conductive. When the sheets are sandwiched together, the nanohairs are attracted to one another and locked in, just like the beetle hairs. The device is then wired up so that an electrical current can be applied, and covered in a layer of soft, protective polymer.