Magnetic Pick, Mechanical Place on Small Scales*

Abstract

Magnetic pick has been used for decades as a means of manipulating parts. However, its scaling advantages on small scales using permanent magnets is perhaps less well known. Permanent magnets can attract and hold parts for pick, and place can be accomplished mechanically using techniques such as sliding to overcome magnetic forces. In addition to scaling advantages, this paper discusses other potential advantages of certain magnetic pick configurations including the ability to suppress double picks, part alignment, high speed acquisition even from random part distributions, and the ability to manipulate parts that are magnetically "doped" at low concentrations. These theoretical aspects are described and illustrated experimentally using a Diamagnetic Micro Manipulation (DM3) system where the micro robots consist of magnet arrays and can be directly used for magnetic pick. Configurations that achieve 1,000 parts pick and place without error, high speed (<1 s) multiple part acquisition and singulation from random 2D part distributions, and magnetic doping that enables manipulation at <2% added mass are described.