Optical tweezers and manipulation of PMMA beads in various conditions

Kotsifaki, DG; Makropoulou, M; Serafetinides, AA

dc.contributor.author	Kotsifaki, DG	en
dc.contributor.author	Makropoulou, M	en
dc.contributor.author	Serafetinides, AA	en
dc.date.accessioned	2014-03-01T02:52:05Z
dc.date.available	2014-03-01T02:52:05Z
dc.date.issued	2009	en
dc.identifier.issn	16057422	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/35834
dc.subject	He:Ne laser	en
dc.subject	Laser ablation	en
dc.subject	Nd:YAG laser	en
dc.subject	Nitrogen laser	en
dc.subject	Optical tweezers	en
dc.subject	PMMA microspheres	en
dc.subject.other	Biomedical research	en
dc.subject.other	Continuous Wave	en
dc.subject.other	CW Nd:YAG laser	en
dc.subject.other	He-Ne lasers	en
dc.subject.other	He:Ne laser	en
dc.subject.other	Index of refraction	en
dc.subject.other	Laser fluences	en
dc.subject.other	Laser scalpel	en
dc.subject.other	Laser sources	en
dc.subject.other	Laser tweezers	en
dc.subject.other	Light scattering theory	en
dc.subject.other	Low Power	en
dc.subject.other	Micro beams	en
dc.subject.other	Micro-ablation	en
dc.subject.other	Micro-particles	en
dc.subject.other	Microscopic control	en
dc.subject.other	ND : YAG lasers	en
dc.subject.other	Nd:YAG laser	en
dc.subject.other	Nitrogen laser	en
dc.subject.other	Optical trap	en
dc.subject.other	Optical trapping and micromanipulation	en
dc.subject.other	PMMA microspheres	en
dc.subject.other	Pulse durations	en
dc.subject.other	Pulsed laser ablation	en
dc.subject.other	Shape deformation	en
dc.subject.other	Spatial intensity distribution	en
dc.subject.other	Stretching force	en
dc.subject.other	Subcellular structure	en
dc.subject.other	System-based	en
dc.subject.other	Trapping efficiencies	en
dc.subject.other	Helium	en
dc.subject.other	Laser ablation	en
dc.subject.other	Laser tissue interaction	en
dc.subject.other	Lasers	en
dc.subject.other	Microoptics	en
dc.subject.other	Microspheres	en
dc.subject.other	Neodymium	en
dc.subject.other	Neon	en
dc.subject.other	Nitrogen	en
dc.subject.other	Optical instruments	en
dc.subject.other	Optical systems	en
dc.subject.other	Optical tweezers	en
dc.subject.other	Pulsed laser applications	en
dc.subject.other	Pulsed laser deposition	en
dc.subject.other	Refraction	en
dc.subject.other	Refractive index	en
dc.subject.other	Neodymium lasers	en
dc.title	Optical tweezers and manipulation of PMMA beads in various conditions	en
heal.type	conferenceItem	en
heal.identifier.primary	10.1117/12.831895	en
heal.identifier.secondary	http://dx.doi.org/10.1117/12.831895	en
heal.identifier.secondary	73731V	en
heal.publicationDate	2009	en
heal.abstract	Laser optical trapping and micromanipulation of microparticles or cells and subcellular structures have gained remarkable interest in biomedical research and applications. Several laser sources are employed for the combination of a laser scalpel with an optical tweezers device, under microscopic control. However, although the principles and the mechanisms of pulsed laser ablation have been well described for macroscopic interventions, the microbeam operation, under microscopic guidance, necessitates further experiments and investigations. We present experimental results of controlled micro-ablation of PMMA beads of 3-8 μm diameters, trapped by laser tweezers in various media e.g. solutes of different index of refraction. An optical tweezers system, based on a continuous wave He-Ne laser emitting at 632.8 nm, was tested on beads and, despite the low power of the He-Ne laser, the optical trap was stable. Another optical system, based on a cw Nd:YAG laser emitting at 1.06 μm, was tested on microspheres too. Successful beads ablation was carried out by irradiation with multiple, or even a single nitrogen laser pulse of 7 ns pulse duration at a wavelength of 337 nm. The ablative perforation of the microspheres was estimated by controlling the laser fluence. Moreover, shape deformations of PMMA microspheres were observed. The experimentally obtained results are theoretically explained via the spatial intensity distribution based on Mie light scattering theory. Furthermore, the appearance of laser ablation holes in the back side of microspheres is explained by the ablation triggered shock waves propagation. The role of the stretching forces action is also discussed. Additionally, we report experimental results on measuring the optical trap force of PMMA beads. A powerful optical tweezers system based on a continuous wave Nd:YAG laser was used in order to estimate the trapping efficiency for several beads diameter. © 2009 SPIE-OSA.	en
heal.journalName	Progress in Biomedical Optics and Imaging - Proceedings of SPIE	en
dc.identifier.doi	10.1117/12.831895	en
dc.identifier.volume	7373	en