Pneumatic Coiling Actuator Inspired by the Awns of .

This study examines the coiling and uncoiling motions of a soft pneumatic actuator inspired by the awn tissue of . These tissues have embedded cellulose fibers distributed in a helical pattern, which induces hygroscopic coiling and uncoiling in response to the daily changes in ambient humidity. Such sophisticated motions can eventually "drill" the seed at the tip of awn tissue into the soil: a drill bit in the plant kingdom.