Review paper in Nature Nanotechnology

Our paper 'Optical trapping and manipulation of nanostructures' has been published in Nature Nanotechnology 8 807-819 (2013).

From the abstract:  Optical trapping and manipulation of micrometre-sized particles was first reported in 1970. Since then, it has been successfully implemented in two size ranges: the subnanometre scale, where light–matter mechanical coupling enables cooling of atoms, ions and molecules, and the micrometre scale, where the momentum transfer resulting from light scattering allows manipulation of microscopic objects such as cells. But it has been difficult to apply these techniques to the intermediate — nanoscale — range that includes structures such as quantum dots, nanowires, nanotubes, graphene and two-dimensional crystals, all of crucial importance for nanomaterials-based applications. Recently, however, several new approaches have been developed and demonstrated for trapping plasmonic nanoparticles, semiconductor nanowires and carbon nanostructures. Here we review the state-of-the-art in optical trapping at the nanoscale, with an emphasis on some of the most promising advances, such as controlled manipulation and assembly of individual and multiple nanostructures, force measurement with femtonewton resolution, and biosensors.

UCL sp2 Carbon Group

Phil is giving a talk to the UCL sp2 Carbon Group on 'Optical Trapping of Carbon Nanomaterials'

This talk will give a brief overview of our experimants on optical tweezers for trapping and maniplation of carbon nanomaterials, including nanotubes and graphene flakes.  It will start with a description of
the experimental techniques of opical trapping and back focal plane interferometry for paricle tracking, then present results on trapping, tracking and the analysis of Brownian motion of trapped carbon nanotube bundles and graphene flakes, including centre-of-mass and angluar fluctuations and driven rotations, and combined optical tweezers and Raman spectroscopy.


References:
O. M. Maragò, F. Bonaccorso, R. Saija, G. Privitera, P. G. Gucciardi, M. A. Iatì, G. Calogero, P. H. Jones, F. Borghese, P. Denti, V. Nicolosi & A. C. Ferrari. 'Brownian motion of graphene', ACS Nano 4 7515-7523 (2010)

O. M. Maragò, R. Saija, F. Borghese, P. Denti, P. H. Jones, E. Messina, G. Compagnini, V. Amendola, M. Meneghetti, M. A. Iatì, and P. G. Gucciardi.  'Plasmon-enhanced optical trapping of metal nanoparticles: force calculations and light-driven rotations of nanoaggregates', Proc. SPIE Vol. 7762, 77622Z (2010)

O. M. Maragò, P. G. Gucciardi and P. H. Jones.  'Photonic Force Microscopy: from femtonewton force sensing to ultra-sensitive spectroscopy', in Scanning Probe Microscopy in Nanoscience and Nanotechnology 1 (Springer) B. Bushan (Ed.) (2010)

P. H. Jones, F. Palmisano, F. Bonaccorso, P. G. Gucciardi, G. Calogero, A. C. Ferrari & O. M. Maragò.  'Rotation detection in light-driven nanorotors',  ACS Nano 3 3077-3084 (2009)

O. M. Maragò, P. H. Jones and A. C. Ferrari. 'A light touch on nanotubes: femtonewton force sensing and nanometric spatial resolution', SPIE newsroom, doi 10.1117/2.1200901.1475 (2009)

O. M. Maragò, P. H. Jones, F. Bonaccorso, V. Scardaci, P. G. Gucciardi, A. Rozhin, and A. C. Ferrari.  'Femtonewton Force Sensing with Optically Trapped Nanotubes', Nano Letters 8 3211-3216 (2008)

O. M. Maragò, P. G. Gucciardi, F. Bonaccorso, G. Calogero, V. Scardaci, A. Rozhin, A. C. Ferrari, P. H. Jones, R. Saija, F. Borghese, P. Denti & M. A. Iatì.  'Optical trapping of carbon nanotubes’, Physica E 40 2347-2351 (2008)

Brownian Motion of Graphene paper

Our paper 'Brownian Motion of Graphene' has been published online in ACS Nano.  

From the abstract:

Brownian motion is a manifestation of the fluctuation-dissipation theorem of statistical mechanics. It regulates systems in physics, biology, chemistry, and finance. We use graphene as prototype material to unravel the consequences of the fluctuation-dissipation theorem in two dimensions, by studying the Brownian motion of optically trapped graphene flakes. These orient orthogonal to the light polarization, due to the optical constants anisotropy. We explain the flake dynamics in the optical trap and measure force and torque constants from the correlation functions of the tracking signals, as well as comparing experiments with a full electromagnetic theory of optical trapping. The understanding of optical trapping of two-dimensional nanostructures gained through our Brownian motion analysis paves the way to light-controlled manipulation and all-optical sorting of biological membranes and anisotropic macromolecules.