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:3/7/2017)... , March 7, 2017   HireVue , the ... global companies identify the best talent, faster, today announced ... Sales Officer (CSO) and Diana Kucer as ... out a seasoned executive team poised to drive continued growth ... on a year of record bookings in 2017. ...
(Date:3/2/2017)... March 2, 2017 Who risk to be ... Download the full report: https://www.reportbuyer.com/product/4313699/ WILL ... SENSOR FIELD? Fingerprint sensors using capacitive technology represent ... sensor vendor Idex forecasts an increase of 360% of ... and of the fingerprint sensor market between 2014 and ...
(Date:2/28/2017)... , February 28, 2017 News solutions for ... ... from 14 to 16 March, Materna will present ... show how seamless travel is a real benefit for passengers. ... biometrics to their passenger touch point solutions to take passengers through ...
Breaking Biology News(10 mins):
(Date:3/27/2017)... ROCKVILLE, Md. , March 27, 2017 /PRNewswire/ ... $108.5 billion for 2016, according to a new ... patients, medical lab testing is performed to evaluate ... determine individual therapy, among other reasons.  The healthcare ... Services Market , provides an overview of ...
(Date:3/27/2017)... 27, 2017  Trovagene, Inc. (NASDAQ: TROV), a precision ... Officer, Bill Welch , will be presenting at ... 9:00 AM EDT at the Essex House in ... Chief Scientific Officer, Mark Erlander , Ph.D., will ... conference.   The presentation will be webcast live ...
(Date:3/24/2017)... -- Research and Markets has announced the addition of ... Business Report" report to their offering. ... This report analyzes the Global market ... estimates and forecasts are provided for the period 2014 through 2022. ... The report profiles 25 companies including many key ...
(Date:3/23/2017)... ... March 23, 2017 , ... AxioMed president, Jake ... and elastic characteristics when deformed, which is identical to how the human discs ... compressive forces and return to its natural state along a hysteresis curve, exactly ...
Breaking Biology Technology: