Automatic Localization of Carbon Nanotubes in the Scanning Electron Mircoscope

When doing automated assembly on the nanoscale, the localization and indexing of the nanoscale objects is challenging. The video shows how a silicon wafer containing cnts is scanned for the single cnts in the SEM. The procedure starts at a low magnification, providing automatic zooming and image optimisation (focus, brightness/contrast) for CNT-localization. The cnts are then magnified in several steps, until tip and bottom end of each CNT is automatically registered. This step is the starting point for any automated assembly process on the nanoscale.

Nanothermal trumpet: thermoacoustic sound source made with a suspended metal nanowire

From the paper “Suspended metal wire array as a thermoacoustic sound source,” Appl. Phys. Lett. 95, 163102 (2009); by AO Niskanen, J. Hassel, M. Tikander, P. Maijala, L. Grönberg, P. Helistö, from VTT Technical Research Centre of Finland, PO BOX 1000, 02044 VTT, Finland. dx.doi.org A suspended metal wire array is used to produce high-pressure sound waves over a wide spectrum using the thermoacoustic effect. It is fabricated with an air-bridge arrays containing up to 2×105 wires covering an area of a few square centimeters. The supporting silicon wafer was isotropically plasma etched to release the wires thereby avoiding heat contact with the substrate. Sound pressure levels reaching 110 db at a distance of 8 cm were demonstrated near 40 khz in free field. The devices are also able to reproduce music and speech. They have potential for applications especially in the ultrasound range.