3D nanorobotic manipulations of multi-walled carbon nanotubes

Multi-walled carbon nanotubes (MWNTs) are manipulated in 3D space with a 10-DOF nanorobotic manipulator, which is actuated with PZTs and Picomotors^TM (New Focus Inc.) and operated inside a scanning electronic microscope (SEM). The coarse linear resolutions of the manipulator are better than 30 nm (X, Y, Z stages actuated by Picomotors) and the rotary one 2 mrad, while the resolutions of fine motions (actuated by PZTs) are within nano-order. AFM cantilevers are used as the end-effector. Several kinds of manipulations of MWNTs are performed with the developed manipulators with the assistance of dielectrophoresis and van der Waals forces. A single MWNT with estimated dimensions of φ 40 nm ×7 μm has been picked up on an AFM cantilever. Another φ 50 nm ×6 μm MWNT is placed between two cantilevers, and still another φ 40 nm ×8 μm MWNT is bent between a cantilever and sample substrate. Carbon nanotube (CNT) junctions are basic building blocks for more complex devices based on CNTs. A cross-junction was constructed with two MWNTs of dimensions of ∼φ 40 nm ×6 μm and ∼φ 50 nm ×7 μm, and a T-junction was made of two MWNTs with the dimensions of ∼φ 40 nm ×3 μm and ∼φ 50 nm ×2 μm. Force measurements are performed and the flexural rigidity and Young´s modulus of an ∼φ 30 nm ×7 μm MWNT are estimated to be 8.641×10^-20 Nm² and 2.17 TPa respectively. Such manipulations are essential for both the property research of CNTs and the fabrication of CNT-based NEMS.