| The precision of Nano-manipulation is seriously affected by manipulation system's end-effectors. With the rapid development of nanotechnology, the fabrication of end-effectors has been widely studied. As one of end-effectors, tungsten probes is very popular lately, which are commonly fabricated by milling, shearing, ultrahigh vacuum field ion microscope or electrochemical etching method and so on, wherein electrochemical etching method has been widely accepted by labs due to its simple equipment, good repeatability, low cost and other advantages. In order to prepare a tungsten probe suitable for manipulating nanomaterials, this paper designed a tungsten probe manufacturing system based on dynamic electrochemical etching method and analyzed the fabrication process. The main work is exhibited as follows:(1) According to the characteristics and requirements of nanoscale probes, dynamic electrochemical etching method has been raised to manufacturing probes that suitable for Nano-manipulation. The mechanism about the method has been explained by establishing a theoretical model.(2) An automatic tungsten probe manufacturing system was designed and made, which includes mechanical part, electronic control part and a user interface. The stroke of tungsten wire in the vertical direction is 60 mm, etching voltage can be easily adjusted between 2 ~ 12 V, the time between probe is formed to cut the etching voltage less than 10?s.(3) A large number of comparative test has been carried out to prepare long and smooth tungsten probes by the manufacturing system. Based on the experimental data, we analyzed the regularity about the formation of probes and finally obtain optimum process parameters, those parameters includes KOH concentration?threshold voltage?etching voltage?the picking-up speed and immersion depth. Under the optimum condition, tungsten probes with aspect ratio over 5 and apex diameter less than 200 nm can be fabricated, and the success rate reach 90%. |
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