Enhancement of Gripping Ability for Soft and Slippery Objects by Using Double-Scale Protrusions

Abstract

Enhancement of surface friction is an important problem for many machine parts and instruments designed to grip or convey soft bodies and sheets. This paper presents an approach to increase gripping ability for soft and slippery objects by using double-scale protrusions: One is millimeter-sized protrusions on a SUS420J2 stainless steel produced by electrical discharge machining and another is micrometer-sized fine protrusions formed by sputter etching. The friction tests of a soft silicone sheet proved that the double-scale protrusions have higher gripping ability than single-scale protrusions in an oil environment.