Posted: August 5, 2008

Lab-on-a-chip Technology: Microfluidics Aids Major Advance in Environmental Testing

(Nanowerk News) Microfluidics experts, Dolomite, in collaboration with the UK’s National Centre for Atmospheric Science have announced the development of a new generation of microfluidics-based environmental testing equipment for use in air quality monitoring.
Microfluidics is an exciting new field of science and engineering that enables very small-scale fluid control and analysis, allowing instrument manufacturers to develop smaller, more cost-effective and more powerful systems. With this lab-on-a-chip technology, entire complex chemical management and analysis systems can be created in a microfluidic chip and interfaced with, for example, electronics and optical detection systems.
 microfluidic device with 7.5 m of micro-channel running through a 10 cm square piece of glass
Dolomite's microfluidic device with 7.5 m of micro-channel running through a 10 cm square piece of glass
Headed by Professor Alastair Lewis, the team from the National Centre for Atmospheric Science is undertaking initial studies to evaluate the feasibility of developing a portable microfluidics-based environmental testing module. Today’s air monitoring procedure usually requires the collection of air samples at remote locations, which then have to be returned to a laboratory for analysis using large and expensive gas chromatography instruments. The procedure is slow and costly. Professor Lewis’s research is aimed at developing a small-scale portable analysis system that will enable air quality to be analyzed and recorded in-situ. Such a system would have a dramatic effect on the speed of response to adverse changes in air quality.
"This is a great application of our technology," said Gillian Davis Regional Manager at Dolomite. "This is what microfluidics does best. It enables smaller, yet more powerful systems to be developed. Systems that may have been laboratory-based, can become more portable or even hand held, and at the same time can have increased accuracy and repeatability."
For this project Dolomite had to create a microfluidic device with an amazing 7.5m of micro-channel running through a 10cm square piece of glass. This is one of the largest devices and longest channels so far developed by Dolomite (this technology tends to be based in a smaller format). The fabrication processes used to create such a microfluidic device have some similarity to those used in the electronics industry. The channels through which the fluids flow and interact are etched into materials such as glass or polymers using similar photolithography processes, for example. The patterned layers are then very accurately aligned and fused together and drilled to provide microscopic ports through which the chemicals or gases can enter and leave the device.
"The real challenge with this project was the fusing of such large etched glass plates," said Gillian Davis. "Aligning the plates to ensure the etched microchannels were perfectly matched took a great deal of experience and put our capabilities to quite a test."
Background Information
A major analytical science success of the 20th Century has been the development of technology to detect trace level chemicals in highly complex mixtures and at the parts per trillion level (pptv; 1picomole per mole) and below. Technology development in this area has been primarily focussed on issues of sensitivity and specificity often at the expense of unit cost, size or operational ease. A major challenge for the 21st Century is therefore to develop miniaturised separation, detection and sensor technologies and harness them together to form highly specific measurement techniques in forms that are low cost, fully autonomous and yet which have all the capabilities of today's laboratory based instruments. The core technologies being developed in this project are micro-fabricated gas chromatography devices (used to detect and quantify chemicals in air, water and soil), etched at the micron level onto glass substrates: a so-called lab-on-a-chip. This is very new engineering technology and is one which is now being activity exploited for biochemical and pharmaceutical applications through the explosion of interest in lab-on-a-chip microfluidics.
The driver for this technology is the lack of a technical solution to the problem of analysing complex gas mixtures cheaply without requiring the collection of gas samples and returning them to the laboratory for analysis using expensive and bulky equipment. The founding rationale for the development has been the bottleneck in volatile organic compound (VOC) data in environmental pollutant measurements.
Dolomite Centre Ltd
Established in 2005 as the world’s first microfluidic application centre, Dolomite is focussed on working with customers to turn their concepts for microfluidic applications into reality. With an in-depth understanding of chemistry and the life sciences, expertise in microfabrication and microfluidics, together with instrument design and development capabilities, Dolomite is enabling some of the world’s top providers in fields as diverse as environmental monitoring, drug discovery and forensic science to deliver microfluidic systems to the market place. To find out more about Dolomite, please visit –
The National Centre for Atmospheric Science
The National Centre for Atmospheric Science (NCAS) is a world leader in atmospheric science. With an annual budget of £9M, NCAS carries out research programmes in climate change science, atmospheric composition (including air quality), weather (including hazardous weather) and state-of-the-art technologies for observing and modelling the atmosphere (including a world-leading research aircraft). We have over 100 research scientists, including UK and world experts to work on our research programmes and provide support to the academic community. These programmes are distributed throughout the UK, at 15 UK universities and research institutes. NCAS also provides research outcomes for government policy-making. NCAS is a research centre of the Natural Environment Research Council with its headquarters at the University of Leeds.
Professor Alastair Lewis is Director of the NCAS Atmospheric Composition programme, and is based at the Chemistry Department, University of York.
Source: Dolomite Centre
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