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Optical trapping force reduction and manipulation of nanoporous beads.

ABSTRACT: We studied the interaction of infrared optical traps with controlled-pore glass (CPG) beads in aqueous medium. The lateral optical trapping force and stiffness were experimentally found considerably smaller than those of their solid counterparts. The simulation using an average refractive index revealed significant losses of effective trapping efficiency, which quantitatively agreed well with experimentally fitted curves. This effect was ascribed to the reduced relative refractive index of medium-filled CPG beads with respect to the medium. Combining optical trapping with mechanical confinements, we demonstrated a microfluidic platform allowing for the synthesis of multiple DNA oligonucleotide sequences on individual beads of interest.

SUBMITTER: Wang T

PROVIDER: S-EPMC3338583 | biostudies-other | 2012 Apr

REPOSITORIES: biostudies-other

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Indirect optical trapping using light driven micro-rotors for reconfigurable hydrodynamic manipulation.

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Stable, Free-space Optical Trapping and Manipulation of Sub-micron Particles in an Integrated Microfluidic Chip.

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In vivo optical trapping indicates kinesin's stall force is reduced by dynein during intracellular transport.

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Fabrication of Fresnel plates on optical fibres by FIB milling for optical trapping, manipulation and detection of single cells.

Project description:The development of economical optical devices with a reduced footprint foreseeing manipulation, sorting and detection of single cells and other micro particles have been encouraged by cellular biology requirements. Nonetheless, researchers are still ambitious for advances in this field. This paper presents Fresnel zone and phase plates fabricated on mode expanded optical fibres for optical trapping. The diffractive structures were fabricated using focused ion beam milling. The zone plates presented in this work have focal distance of ~5?µm, while the focal distance of the phase plates is ~10?µm. The phase plates are implemented in an optical trapping configuration, and 2D manipulation and detection of 8?µm PMMA beads and yeast cells is reported. This enables new applications for optical trapping setups based on diffractive optical elements on optical fibre tips, where feedback systems can be integrated to automatically detect, manipulate and sort cells.

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