Researchers at the University of Western Ontario, Canada, are developing a bottom-up strategy for building nanosystems. The approach uses three flows, one sample flow in the middle of two sheath flows, to hydrodynamically focus nanocomponents ready for assembly.

The sample flow is clamped laterally by the two sheath flows, which act as a pair of hydro-tweezers. By adjusting the flow ratio of the sheath flow to the sample flow, it is possible to focus the sample flow and shift this stream over the entire flow field. If the sample flow contains suspended nanowires then these nanowires will deposit onto the surface beneath the sample flow.

The hydro-tweezers can be used to deliver nanowires to desired positions on a substrate and the approach could enable new applications in nanoelectronics, biosensors and materials science, with no material limitation.

More details, including images of deposited silver nanowires, can be found in the journal Nanotechnology.