Ultrafast nano generation of acoustic waves in water via a single carbon nanotube

• DOI: 10.1016/j.pacs.2022.100407
• Publication Date: 2022-09-29T19:14:54Z
• Authors: Michele Diego; Marco Gandolfi; Alessandro Casto; Francesco Maria B...; Fabien Vialla; Aurélien Crut; Stefano Roddaro; Matteo Fasano; Fabrice Vallée; Natalia Del Fatti; Paolo Maioli; Francesco Banfi
• Keywords: Ranging

Generation of ultra high frequency acoustic waves in water is key to nano resolution sensing, imaging and theranostics. In this context immersed carbon nanotubes (CNTs) may act as an ideal optoacoustic source, due their nanometric radial dimensions, peculiar thermal properties broad band optical absorption. The generation mechanism water, upon excitation both a single-wall (SW) multi-wall (MW) CNT with laser pulses temporal width ranging from 5 ns down ps, theoretically investigated via multiscale approach. We show that, depending on the combination size pulse duration, can thermophone or mechanophone. As thermophone, acts nanoheater for surrounding which, expansion, launches pressure wave. mechanophone, nanopiston, its expansion directly triggering wave water. Activation mechanophone effect sought trigger few nanometers wavelength sound matching frequencies. This at variance respect commonly addressed case water-immersed single metallic nano-objects excited pulses, where only significantly contributes. present findings might be impact fields nanoscale non-destructive testing dynamics meso nanoscale.