High-Aspect Ratio Metallic Nano Grippers

We report the fabrication and characterization of a submicron metallic electrothermal gripper using a combination of electron beam (e-beam) lithography and electroplating techniques. An SU-8 layer was used as a sacrificial layer and polymethyl methacrylate (PMMA) resist was patterned using e-beam lithography to create ~3:1 aspect ratio (1 μm thick, 350 nm critical feature width) mold for electroplating. Nickel was electroplated and resist layers were removed to make the device suspended. The submicron gripper was characterized using a nanomanipulator installed in a dual-beam focused ion beam system. The jaw closing up to 1.39 m with an applied current of 28 mA has been reproducibly observed, which is corresponding to the maximum power consumption of 11.2 mW. Finite element analysis (FEA) using ANSYS was performed and the FEA results showed a good agreement with the measured results.