Biomedical subjects

Yael Roichman

Publications and source records attributed to Yael Roichman.

3 recordsLinked to original sources

PubMed2006

Optical traps with geometric aberrations.

We assess the influence of geometric aberrations on the in-plane performance of optical traps by studying the dynamics of trapped colloidal spheres in deliberately distorted holographic optical tweezers. The lateral stiffness of the traps turns out to be insensitive to moderate amounts of coma, astigmatism, and spherical aberration. Moreover holographic aberration correction enables us to compensate inherent shortcomings in the optical train, thereby adaptively improving its performance. We also demonstrate the effects of geometric aberrations on the intensity profiles of optical vortices, whose readily measured deformations suggest a method for rapidly estimating and correcting geometric aberrations in holographic trapping systems.

Journal Article↗

PubMed2006

Holographic optical trapping.

Holographic optical tweezers use computer-generated holograms to create arbitrary three-dimensional configurations of single-beam optical traps that are useful for capturing, moving, and transforming mesoscopic objects. Through a combination of beam-splitting, mode-forming, and adaptive wavefront correction, holographic traps can exert precisely specified and characterized forces and torques on objects ranging in size from a few nanometers to hundreds of micrometers. Offering nanometer-scale spatial resolution and real-time reconfigurability, holographic optical traps provide unsurpassed access to the microscopic world and have found applications in fundamental research, manufacturing, and materials processing.

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PubMed2004

Propagation of interacting force chains in the continuum limit.

We study the effect of mergers in the force chain model describing the stress profile in static granular materials. Combining numerical and analytical calculations, we show that granular materials do not generally behave in an elasticlike manner; however, they may under specific conditions, which are elaborated. Nonelastic behavior resulting from the nonlinearity of the full force chain model is discussed.

Journal Article↗