Contact trapping, alignment and 3D transfer of a single nanowire using acoustic streaming

The acoustic streaming, which usually flushes trapped entities away, has been viewed as a negative factor in acoustic trapping. Here we report a method that uses mobile acoustic streaming to effectively trap a single nanowire within water film on substrate surface. The streaming is generated by a micro-probe with uniform diameter and in vibration. The trapped nanowire, which is pushed onto the micro-probe surface by the streaming, is constantly perpendicular to the micro-probe vibration and symmetric about the micro-probe approximately. It can be stably transferred through any 3D path in the water film by moving the micro-probe.