Navigation Links
Marriage of microfluidics and optics could advance lab-on-a-chip devices
Date:2/16/2010

CAMBRIDGE, Mass., February 15, 2009 -- With a silicone rubber "stick-on" sheet containing dozens of miniature, powerful lenses, engineers at Harvard are one step closer to putting the capacity of a large laboratory into a micro-sized package.

The marriage of high performance optics with microfluidics could prove the perfect match for making lab-on-a-chip technologies more practical.

Microfluidics, the ability to manipulate tiny volumes of liquid, is at the heart of many lab-on-a-chip devices. Such platforms can automatically mix and filter chemicals, making them ideal for disease detection and environmental sensing.

The performance of these devices, however, is typically inferior to larger scale laboratory equipment. While lab-on-a-chip systems can deliver and manipulate millions of liquid drops, there is not an equally scalable and efficient way to detect the activity, such as biological reactions, within the drops.

The Harvard team's zone-plate array optical detection system, described in an article appearing in Lab on a Chip (Issue 5, 2010), may offer a solution. The array, which integrates directly into a massively parallel microfluidic device, can analyze nearly 200,000 droplets per second; is scalable and reusable; and can be readily customized.

"In essence, we've integrated some high performance optics onto a chip that contains microfluidics as well. This allows us to be able to parallelize the optics in the same way that a microfluidic device parallelizes sample manipulation and delivery," says Ken Crozier, an Associate Professor of Electrical Engineering at the Harvard School of Engineering and Applied Sciences (SEAS) who directed the research.

Unlike a typical optical detection system that uses a microscope objective lens to scan a single laser spot over a microfluidic channel, the team's zone-plate array is designed to detect light from multiple channels simultaneously. In their demonstration, a 62 element zone-plate array measured a fluorescence signal from drops traveling down 62 channels of a highly parallel microfluidic device.

The device works by creating a focused excitation spot inside each channel in the array and then collects the resulting fluorescence emission from water drops traveling through the channels, literally taking stop-motion pictures of the drops as they pass.

"Water drops flow through each channel of the device at a rate of several thousand per second," explains lead author Ethan Schonbrun, a graduate student at SEAS. "Each channel is monitored by a single zone plate that both excites and collects fluorescence from the high speed drops. By using large arrays of microfluidic channels and zone plate lenses, we can speed up microfluidic measurements."

The series of images are then recorded by a digital semiconductor (CMOS) camera, allowing high speed observation of all the channels simultaneously. Moreover, the array is designed so that each zone plate collects fluorescence from a well-defined region of the channel, thereby avoiding cross talk between adjacent channels. The end result is a movie of the droplets dancing through the channels.

"Our approach allows us to make measurements over a comparatively large area over the chip. Most microscopes have a relatively limited view and cannot see how the whole system is working. With our device, we can place lenses wherever we want to make a measurement," adds Crozier.

The system can detect nearly 200,000 drops per second, or about four times the existing state-of-the-art detection systems. Further, the lens array is scalable, without any loss in efficiency, and can be peeled on-and-off like a reusable sticker. Ultimately, the integrated design offers the sensitivity of a larger confocal microscope and the ability to measure over a larger area, all in a much smaller, cheaper package.

"Because we have this massively parallel approacheffectively like 62 microscopeswe can get very high measurement or data rates," says Crozier. "This device has shown we can measure up to 200,000 drops per second, but I think we can push it even further."

Nanophotonics experts Schonbrun and Crozier originally developed the zone-plate technology to enhance optical tweezers so they could grab particles in a liquid using light. Using the high numerical aperture that makes efficient optical tweezers, they realized that arrays of zone plates could also be used to implement an efficient and scalable optical detection platform.

The researchers, who have filed a patent on their invention, are optimistic that with further research and development, the device could enhance a range of microfluidic and microfluidic-based lab-on-chip devices and speed the advance of using them for applications such as in-the-field biological assays.


'/>"/>

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

Related biology technology :

1. Microfluidics Chairman James N. Little, Ph.D., Announces Retirement from Board of Directors
2. Microfluidics International Corporation Announces Third Quarter 2009 Financial Results
3. Microfluidics International Corporation to Report Third Quarter 2009 Financial Results on November 2, 2009
4. Microfluidics International Corporation Announces Second Quarter 2009 Financial Results
5. Microfluidics International Corporation to Report Second Quarter 2009 Financial Results on August 11, 2009
6. Particle Sciences and Microfluidics Collaborate to Share Formulation and Nanotechnology Expertise for Pharmaceutical Drug Product Development, Analysis and Commercialization
7. Nanopoint Applies CE Mark to Its cellTRAY(R) Imaging and Microfluidics Systems
8. Microfluidics Expands Distributorship in Japan with Exclusive POWREX Partnership to Meet Increased Demand in Pharmaceutical, Biotechnology and Energy Industries
9. GEN Reports on Growing Reliance on Microfluidics Technology
10. RainDance Technologies to Present Sequence Enrichment Using Droplet-Based Microfluidics Workshop at ASHG 2008
11. Optics made to measure
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
Marriage of microfluidics and optics could advance lab-on-a-chip devices
(Date:5/4/2016)... ... 2016 , ... The Children’s Tumor Foundation announced its annual month-long campaign to ... nerves throughout the body. It affects 1 in 3,000 people of all populations; there ... month of May, as well as online activities, Neurofibromatosis Awareness Month and “I Know ...
(Date:5/4/2016)... ... 2016 , ... PBI-Gordon Corporation is pleased to announce Doug Obermann has been ... career at PBI-Gordon in February 1988, after finishing his masters in agronomy from Iowa ... customer service to national product manager, to helping develop, name and launch many of ...
(Date:5/3/2016)... , May 3, 2016 ... (Genomics, Drug Discovery, Gene Expression) Lab-on-a-chip (IVD ... (Academics Institutes, Diagnostics Centers), Fabrication Technology (Microarrays, ... MarketsandMarkets, the market is expected to reach ... 7.63 Billion in 2015, growing at a ...
(Date:5/3/2016)... ... May 03, 2016 , ... In a list published by the ... state’s 76 fastest-growing private companies; a small percentage of the state's 615,000+ small businesses. ... the percent change in revenue from 2012 to 2015. , As this ...
Breaking Biology Technology:
(Date:3/14/2016)... Florida , March 14, 2016 ... the growing mobile commerce market, announces the airing of a ... channels starting the week of March 21 st .  The ... CNBC, including its popular Squawk on the Street show. ... focused on the growing mobile commerce market, announces the airing ...
(Date:3/10/2016)... , March 10, 2016   Unisys Corporation (NYSE: ... Border Protection (CBP) is testing its biometric identity solution ... Diego to help identify certain non-U.S. citizens leaving ... The test, designed to help determine the efficiency and accuracy ... in February and will run until May 2016. --> ...
(Date:3/3/2016)... Calif. , March 3, 2016  FlexTech, a ... the categories of Innovation, Research & Development, Leadership in ... Leadership. This is the 9 th year of ... group of companies and individuals from past years ... based on a pre-described set of criteria, by a ...
Breaking Biology News(10 mins):