Microfluidics help lab-on-a-chip development skyrocket

Sep 28 2004

Lab-on-a-chip (LOC) development has skyrocketed in the last couple of years due to constant efforts in harnessing microfluidics and µTAS to improve the LOC design and function. The distinct advantages that they bestow on applications are pushing the commercial potential of LOCs.

LOCs will have a significant impact on the diagnostics industry, both in terms of centralised lab analysis and point-of-care testing. With the current worldwide market for diagnostics well over USD 25 billion, LOCs have immense potential in this area.

"While conventional laboratory analysis is time consuming, tedious, and requires expensive equipment and highly trained personnel, bench-top analysis in LOCs can be several times cheaper and faster," explains Analyst Katherine Austin from Technical Insights, a business unit of Frost & Sullivan.

LOCs are also making their mark in high throughput drug screening. Analysis of potential drug candidates is a large-scale and automated process, requiring technology that achieves higher accuracy and throughput compared to standard, macroscale, automated equipment.

"This dynamic, coupled with the need to reduce sample volumes and reagent costs, makes drug discovery and development a prime target for LOCs that offer precision, flexibility, and ease-of-use," asserts Dr. Austin.

The need to combat terrorism and biowarfare is also driving LOC research, making it the 'next big thing' in bioanalytical applications. Besides DNA analysis, there is a growing demand for easy-to-use analytical LOC systems that ensure safety of air, food, and water.

Much of the success of microfluidics and µTAS in creating commercially viable LOC devices is, in large part, due to enabling technologies such as Micro-Electromechanical Systems (MEMS), which enables production of several identical systems concurrently.

In Italy, researchers are leveraging the benefits of MEMS technology to develop a prototype silicon chip that shows great potential for both medical and environmental applications. The chip has excellent thermal properties, ideal for DNA analysis techniques such as polymerase chain reaction (PCR).

Microfluidics and µTAS researchers are also considering the use of polymers and plastics in the LOC design in order to reduce the costs associated with silicon and glass. Despite initial compatibility issues, researchers are learning to work with plastics by applying surface modifications or coatings and manipulating polymer chemistry.

A significant portion of the commercial manufacturing of LOCs currently focuses on disposable chips, cards, or discs through inexpensive injection moulding. These LOCs are easier to manufacture and handle, enabling the development of lower cost, more rugged and flexible electronic devices.

The high development cost of microfluidics and µTAS technologies is a significant issue that threatens to slow the adoption of LOC devices. In addition, the key to LOCs' long-term commercial success is for researchers to look beyond the design mechanics and gain a better understanding of exact market needs.

Many target customers have already installed expensive dispensers and high-throughput screening systems, which means that the market for LOC microfluidic systems is likely to be limited unless the technology demonstrates sufficient benefits to justify additional investment, or sufficient flexibility to integrate into existing systems.

"Portability, rapid assay times, and smaller sample requirements are predicted to aid in the early adoption of LOC technology by the defence and public health sectors. These attributes are likely to take precedence over cost," notes Dr. Austin.

Microfluidic and µTAS research is also moving away from single-task devices that are not reconfigurable towards integrating multiple functions such as sample preparation, enzymatic reactions, filtration, and electrospray ionization onto the same chip.

In Sweden, researchers have developed a nano-lab on a CD, which can process 480 protein samples simultaneously within an hour, for peptide mapping or sequence analysis in mass spectrometry. It is expected to gain wide acceptance in proteomics while popularising the use of microfluidics and µTAS in other fields.

The timing is perfect to stretch the limits of microfluidics and µTAS for LOC development. At this point, almost anything can be embedded into an active microfluidics LOC, including sensors, filtration membranes, optics, digital readouts, and global positioning system chips.