Sequential batch assembly of 3-D microstructures with elastic hinges by a magnetic field

This paper describes three-dimensional (3-D) microstructure assembly using an external magnetic field. An external magnetic field perpendicular to a substrate lifts up a hinged structure due to the shape magnetic anisotropy. Micro flap structures (4.5 /spl mu/m-thick electroplated Permalloy) having 0.2 /spl mu/m-thick nickel elastic hinges with various lengths and widths are bent in out-of-plane direction in a magnetic field up to 50 kA/m. The volume of magnetic material and the stiffness of the hinges determine the sensitivity to a magnetic field. As a result, we realized sequential batch assembly using the difference of the sensitivity. By way of the example, we have erected plates 600 /spl mu/m /spl times/ 600 /spl mu/m in size. Also, structures bent at 90 and 45 degrees out of the plane have been obtained at the same time.