Durability improvement of micro-pin array for a gripper on surface with fine asperities

Abstract

In this study, durability of micro-pin array fabricated using nanosecond pulsed laser beam machining is improved for wall attachment mechanism of a climbing robot. Fabrication of micro-pin array using nanosecond pulsed laser beam machining was previously studied for simply clinging on the wall. However, due to low durability of pins, tips of pins were broken after multiple uses so the broken pins were not able to get interlocked. This study suggests a new method to increase durability of pin array for continuous use while increasing the maximum interlocking force of pins. Electrochemical etching process was used for durability improvement and interlocking force increment of pin array was gained through controlling line spacing and tip radius. Maximum interlocking force of pin has increased from 176.48 mN/mm2 to 205.32 mN/mm2, and 205.32 mN/mm2 of constant and steady interlocking force could be achieved after multiple uses without damaging tip of micro-pin array.