title: Switchable Dry Adhesion with Step-like Micropillars and Controllable Interfacial Contact.
abstract: Dry adhesives have attracted much attention because of their repeatable and reversible attachment. Many research groups have made fruitful achievements in fabricating and designing various dry adhesives. However, most of these studies focus on imitating bioinspired geometry to achieve this smart adhesion, neglecting the contact interface control through their peeling motion. Here, we present an alternative design to achieve this switchable adhesion on the basis of controlling contact areas. This unique design includes micropillars array with large overhanging caps and a "step" located at the center line of the cap. When dragging the pillars in the direction of the upper surface of the step, the lower surface is brought into contact, rapidly yielding stronger adhesion (switched-on state). Alternatively, when dragging the pillars in the direction of the lower surface of the step, the contact areas decrease sharply, leading to weak adhesion (switched-off state). Such switchable property under strong adhesion force is exactly what many practical applications need, and the ability to achieve this property by controlling the adhesion area size presented here opens a new way to dry adhesives design.
authors.affiliation: Micro- and Nano-technology Research Center, State Key Laboratory for Manufacturing Systems Engineering, Xi'an Jiaotong University , Xi'an, Shaanxi 710049, China.
authors.forename: Yue
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Micro- and Nano-technology Research Center, State Key Laboratory for Manufacturing Systems Engineering, Xi'an Jiaotong University , Xi'an, Shaanxi 710049, China.
authors.forename: Hongmiao
authors.initials: H
authors.lastname: Tian
authors.affiliation: Micro- and Nano-technology Research Center, State Key Laboratory for Manufacturing Systems Engineering, Xi'an Jiaotong University , Xi'an, Shaanxi 710049, China.
authors.forename: Jinyou
authors.initials: J
authors.lastname: Shao
authors.affiliation: Department of Mechanical Engineering, University of Alberta , Edmonton, Alberta T6G 1H9, Canada.
authors.forename: Dan
authors.initials: D
authors.lastname: Sameoto
authors.affiliation: Micro- and Nano-technology Research Center, State Key Laboratory for Manufacturing Systems Engineering, Xi'an Jiaotong University , Xi'an, Shaanxi 710049, China.
authors.forename: Xiangming
authors.initials: X
authors.lastname: Li
authors.affiliation: Micro- and Nano-technology Research Center, State Key Laboratory for Manufacturing Systems Engineering, Xi'an Jiaotong University , Xi'an, Shaanxi 710049, China.
authors.forename: Li
authors.initials: L
authors.lastname: Wang
authors.affiliation: Micro- and Nano-technology Research Center, State Key Laboratory for Manufacturing Systems Engineering, Xi'an Jiaotong University , Xi'an, Shaanxi 710049, China.
authors.forename: Hong
authors.initials: H
authors.lastname: Hu
authors.affiliation: Micro- and Nano-technology Research Center, State Key Laboratory for Manufacturing Systems Engineering, Xi'an Jiaotong University , Xi'an, Shaanxi 710049, China.
authors.forename: Yucheng
authors.initials: Y
authors.lastname: Ding
authors.affiliation: Micro- and Nano-technology Research Center, State Key Laboratory for Manufacturing Systems Engineering, Xi'an Jiaotong University , Xi'an, Shaanxi 710049, China.
authors.forename: Bingheng
authors.initials: B
authors.lastname: Lu
keywords: biomimetic design; dry adhesion; overhanging caps; step-like micropillars; switchable contact