Navigation Links
By 'putting a ring on it,' microparticles can be captured
Date:7/20/2010

Cambridge, Mass., July 20, 2010 To trap and hold tiny microparticles, engineers at Harvard have "put a ring on it," using a silicon-based circular resonator to confine particles stably for up to several minutes.

The advance, published in the June 14 issue of Nano Letters, could one day lead to the ability to direct, deliver, and store nanoparticles and biomolecules on all-optical chips.

"We demonstrated the power of what we call resonant cavity trapping, where a particle is guided along a small waveguide and then pulled onto a micro-ring resonator," explains Kenneth Crozier, an Associate Professor of Electrical Engineering at the Harvard School of Engineering and Applied Sciences (SEAS) who directed the research. "Once on the ring, optical forces prevent it from escaping, and cause it to revolve around it."

The process looks similar to what you see in liquid motion toys, where tiny beads of colored drops run along plastic tracksbut on much smaller scale and with different physical mechanisms. The rings have radii of a mere 5 to 10 micrometers and are built using electron beam lithography and reactive ion etching.

Specifically, laser light is focused into a waveguide. Optical forces cause a particle to be drawn down toward the waveguide, and pushed along it. When the particle approaches a ring fabricated close to the waveguide, it is pulled from the waveguide to the ring by optical forces. The particle then circulates around the ring, propelled by optical forces at velocities of several hundred micrometers-per-second.

While using planar ring resonators to trap particles is not new, Crozier and his colleagues offered a new and more thorough analysis of the technique. In particular, they showed that using the silicon ring results in optical force enhancement (5 to 8 times versus the straight waveguide).

"Excitingly, particle-tracking measurements with a high speed camera reveal that the large transverse forces stably localize the particle so that the standard deviation in its trajectory, compared to a circle, is as small as 50 nm," says Crozier. "This represents a very tight localization over a comparatively large distance."

The ultimate aim is to develop and demonstrate fully all-optical on chip manipulation that offers a way to guide, store, and deliver both biological and artificial particles.


'/>"/>

Contact: Michael Patrick Rutter
mrutter@seas.harvard.edu
617-496-3815
Harvard University
Source:Eurekalert  

Related biology news :

1. Putting a green cap on garbage dumps
2. Putting limits on vitamin E
3. Americans want Uncle Sams help putting healthy foods on their dinner table
4. Thrill-seeking holidaymakers are putting dolphins at risk
5. Thrill-seeking holiday-makers are putting dolphins at risk
6. Putting bacterial antibiotic resistance into reverse
7. Drug-embedded microparticles bolster heart function in animal studies
8. Scientists guide immune cells with light and microparticles
9. First known instance of a cricket as an orchid pollinator captured on film by Kew scientist
10. Caught on tape: Muscle stem cells captured on video by MU researcher
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
By 'putting a ring on it,' microparticles can be captured
(Date:7/20/2017)... DAL ) customers now can use fingerprints instead of their ... (DCA). ... launches biometrics to board aircraft at Reagan Washington National Airport ... Delta,s biometric boarding pass experience that launched in May at ... process to allow eligible Delta SkyMiles Members who are enrolled in CLEAR ...
(Date:5/23/2017)... 2017  Hunova, the first robotic gym for the rehabilitation and functional ... in Genoa, Italy . The first 30 robots will ... USA . The technology was developed and patented at ... IIT spin-off Movendo Technology thanks to a 10 million euro investment from ... click: ...
(Date:4/24/2017)... -- Janice Kephart , former 9/11 Commission ... LLP (IdSP) , today issues the following statement: ... 6, 2017 Executive Order: Protecting the Nation ... instilled with greater confidence, enabling the reactivation of ... are suspended by until at least July 2017). ...
Breaking Biology News(10 mins):
(Date:10/10/2017)... International research firm Parks Associates announced today that Tom ... 2017 Annual Meeting , October 11 in Scottsdale, Arizona ... and how smart safety and security products impact the competitive landscape. ... Parks Associates: Smart Home Devices: Main Purchase Driver ... "The residential security market has experienced continued growth, and ...
(Date:10/10/2017)... ... October 10, 2017 , ... USDM Life Sciences , ... life sciences and healthcare industries, announces a presentation by Subbu Viswanathan and Jennifer ... “Automating GxP Validation for Agile Cloud Platforms,” will present a revolutionary approach to ...
(Date:10/9/2017)... 2017  BioTech Holdings announced today identification and ... ProCell stem cell therapy prevents limb loss in ... demonstrated that treatment with ProCell resulted in more ... compared to standard bone marrow stem cell administration.  ... reduction of therapeutic effect.  ...
(Date:10/9/2017)... ... October 09, 2017 , ... At its national board meeting in North ... in Harvard University’s Departments of Physics and Astronomy, has been selected for membership in ... winning team for the 2015 Breakthrough Prize in Fundamental physics for the discovery of ...
Breaking Biology Technology: