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Piezoelectric stick–slip drive nanopositioners are of central importance in in situ SEM nanorobotic systems due to their high precise positioning, large stroke, high speed, and compact structure. However, the output velocity under high load will be seriously influenced. In this paper, a new piezoelectric stick–slip drive nanopositioner with large velocity under high load by introducing the adjust bolts to decouple the driving unit and moving unit is presented. A MATLAB simulation model has been created to optimize the nanopositioner for a certain velocity, and a FEM is used to confirm that the leaf hinge has sufficient stiffness. The size of the prototype is 30 × 32 × 25 mm3. Testing results indicate that the nanopositioner achieves a maximum velocity of 3.467 mm/s and a minimum resolution of 6 nm. When the load increases from 0.4 kg to 2 kg, the maximum velocities only decrease from 3.457 mm/s to 3.143 mm/s. The proposed piezoelectric stick–slip nanopositioner shows large velocity under high load. [ABSTRACT FROM AUTHOR]

A multifunctional electrospinning system has been developed to fabricate diversified nanofibrous structures. It consists of a high voltage power supply, a syringe pump, and a cage like collector that are dominated via the controller by setting parameters from a touch screen. As the key component, speed, and diameter of the collector can be adjusted automatically according to predetermined requirement, which enhances the flexibility of the system. Well-aligned nanofiber array, nanofibrous membrane, and 3D nanofibrous structure were obtained successfully through the technique. This work should be of help to construct functional nanofibrous materials for promoting the development of electrospinning. [ABSTRACT FROM AUTHOR]

This note presents two experimental techniques for mechanical and electrical characterization of individual nanowires inside a scanning electron microscope (SEM). Tensile testing is realized by transferring a nanowire to a microelectromechanical systems device that stretches the nanowire and measures the elongations and tensile forces. The device consists of an electrostatic actuator and two capacitive sensors, capable of acquiring all measurement data (force and displacement) electronically without relying on electron microscopy imaging. For electrical characterization, four-point probe measurement of individual nanowires is performed automatically by controlling four nanomanipulators with SEM visual feedback. A feedforward controller is incorporated into the control system to improve the response time. This work represents advances in nanomaterial testing and automated nanomanipulation. [ABSTRACT FROM AUTHOR]