Figure 1.

(a) Design of the multi-layer mold. Through-hole patterns were etched on the stainless steel template. It was matched with the glass substrate coated a polydimethylsiloxane (PDMS) layer to form a multi-layer mold. (b) Fabrication of magnetic micromachines. Nickel nanoparticles were mixed with PDMS and poured into the mold. After heating and demolding, the magnetic micromachine peeled off. (c) Macro view of micromachines. Apart from the clamp shape, circles and rectangles were designed, ranging from 2000 μm × 1000 μm × 300 μm to 300 μm × 300 μm × 300 μm. (d) Micro view of micromachines with the clamp shape. (e) Hysteresis (magnetic moment-external field) of a micromachine measured by vibrating sample magnetometer (VSM).