Subscribe free to our newsletters via your
. 24/7 Space News .




TECH SPACE
Fast and accurate 3-D imaging technique to track optically trapped particles
by Staff Writers
Daejeon, South Korea (SPX) Apr 27, 2015


This picture shows the concept image of tweezing an optically trapped glass bead on the cellular membrane of a white blood cell. Image courtesy KAIST. For a larger version of this image please go here.

Optical tweezers have been used as an invaluable tool for exerting micro-scale force on microscopic particles and manipulating three-dimensional (3-D) positions of particles. Optical tweezers employ a tightly-focused laser whose beam diameter is smaller than one micrometer (1/100 of hair thickness), which generates attractive force on neighboring microscopic particles moving toward the beam focus.

Controlling the positions of the beam focus enabled researchers to hold the particles and move them freely to other locations so they coined the name "optical tweezers."

To locate the optically-trapped particles by a laser beam, optical microscopes have usually been employed. Optical microscopes measure light signals scattered by the optically-trapped microscopic particles and the positions of the particles in two dimensions.

However, it was difficult to quantify the particles' precise positions along the optic axis, the direction of the beam, from a single image, which is analogous to the difficulty of determining the front and rear positions of objects when closing an eye due to a lack of depth perception.

Furthermore, it became more difficult to measure precisely 3-D positions of particles when scattered light signals were distorted by optically-trapped particles having complicated shapes or other particles occlude the target object along the optic axis.

Professor YongKeun Park and his research team in the Department of Physics at the Korea Advanced Institute of Science and Technology (KAIST) employed an optical diffraction tomography (ODT) technique to measure 3-D positions of optically-trapped particles in high speed.

The principle of ODT is similar to X-ray CT imaging commonly used in hospitals for visualizing the internal organs of patients. Like X-ray CT imaging, which takes several images from various illumination angles, ODT measures 3-D images of optically-trapped particles by illuminating them with a laser beam in various incidence angles.

The KAIST team used optical tweezers to trap a glass bead with a diameter of 2 micrometers, and moved the bead toward a white blood cell having complicated internal structures. The team measured the 3-D dynamics of the white blood cell as it responded to an approaching glass bead via ODT in the high acquisition rate of 60 images per second.

Since the white blood cell screens the glass bead along an optic axis, a conventionally-used optical microscope could not determine the 3-D positions of the glass bead. In contrast, the present method employing ODT localized the 3-D positions of the bead precisely as well as measured the composition of the internal materials of the bead and the white blood cell simultaneously.

Professor Park said, "Our technique has the advantage of measuring the 3-D positions and internal structures of optically-trapped particles in high speed without labelling exogenous fluorescent agents and can be applied in various fields including physics, optics, nanotechnology, and medical science."

Kyoohyun Kim, the lead author of this paper, added, "This ODT technique can also apply to cellular-level surgeries where optical tweezers are used to manipulate intracellular organelles and to display in real time and in 3-D the images of the reaction of the cell membrane and nucleus during the operation or monitoring the recovery process of the cells from the surgery."

The research results ("Simultaneous 3D Visualization and Position Tracking of Optically Trapped Particles Using Optical Diffraction Tomography") were published as the cover article in the April 2014 issue of Optica, the newest journal launched last year by the Optical Society of America (OSA) for rapid dissemination of high-impact results related to optics.


Thanks for being here;
We need your help. The SpaceDaily news network continues to grow but revenues have never been harder to maintain.

With the rise of Ad Blockers, and Facebook - our traditional revenue sources via quality network advertising continues to decline. And unlike so many other news sites, we don't have a paywall - with those annoying usernames and passwords.

Our news coverage takes time and effort to publish 365 days a year.

If you find our news sites informative and useful then please consider becoming a regular supporter or for now make a one off contribution.
SpaceDaily Contributor
$5 Billed Once


credit card or paypal
SpaceDaily Monthly Supporter
$5 Billed Monthly


paypal only


.


Related Links
The Korea Advanced Institute of Science and Technology
Space Technology News - Applications and Research






Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle








TECH SPACE
Tethers Unlimited to recycle ISS plastic waste into 3D printer filament
Bothell WA (SPX) Apr 22, 2015
NASA has announced that its Small Business Innovation Research (SBIR) Program has selected Tethers Unlimited, Inc. (TUI) for award of a Phase II contract to develop a "Positrusion" recycling system for the International Space Station (ISS) and future deep-space manned missions. The Positrusion recycler will convert plastic waste into high-quality 3D printer filament for use in making tools, repl ... read more


TECH SPACE
Russia Invites China to Join in Creating Lunar Station

Japan to land first unmanned spacecraft on moon in 2018

Dating the moon-forming impact event with meteorites

Japan to land probe on the moon in 2018

TECH SPACE
Rover on the Lookout for Dust Devils

UAE opens space center to oversee mission to Mars

Robotic Arm Gets Busy on Rock Outcrop

Mars might have liquid water

TECH SPACE
The Mysteries of Astronautics

General Dynamics Integrates NASA's SGSS Infrastructure

India Role Model in Space Science Benefiting Common Man

Space law is no longer beyond this world

TECH SPACE
Xinhua Insight: How China joins space club?

Chinese scientists mull power station in space

China completes second test on new carrier rocket's power system

China's Yutu rover reveals Moon's "complex" geological history

TECH SPACE
Progress Incident Not Threatening Orbital Station, Work of Crew

Russia loses control of unmanned spacecraft

Japanese astronaut to arrive in ISS in May

Liquid crystal bubbles experiment arrives at International Space Station

TECH SPACE
Ariane 5 gives dual lift" to the THOR 7 and SICRAL 2 satellites

Ariane 5's first launch of 2015

Sentinel-2A payload processing begins for Vega launch in June

45th Space Wing successfully launches first-ever Turkmenistan satellite

TECH SPACE
Titan's Atmosphere Useful In Study Of Hazy Exoplanets

Tau Ceti Probably not the next Earth

Astronomers join forces to speed discovery of habitable worlds

Robotically discovering Earth's nearest neighbors

TECH SPACE
Fast and accurate 3-D imaging technique to track optically trapped particles

Mechanical cloaks of invisibility - without complicated mathematics

ASC Signal To Supply Globecomm With Earth Stations and Upgrades

Reducing big data using quantum theory




The content herein, unless otherwise known to be public domain, are Copyright 1995-2014 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement All images and articles appearing on Space Media Network have been edited or digitally altered in some way. Any requests to remove copyright material will be acted upon in a timely and appropriate manner. Any attempt to extort money from Space Media Network will be ignored and reported to Australian Law Enforcement Agencies as a potential case of financial fraud involving the use of a telephonic carriage device or postal service.