Dolomite Microfluidic Mixer Has Potential to Accelerate Drug Discovery

Cambridge microfluidics company Dolomite is developing technology that allows the rapid mixing and analysis of chemicals, helping instrument manufacturers worldwide to create faster systems that will accelerate drug discovery and enable more effective point of care equipment.

At the root of this technology is an emerging science called ‘microfluidics’, also called 'lab-on-a-chip'. 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 lab-on-a-chip technology, entire complex chemical management and analysis systems are created in a microfluidic chip and interfaced with, for example, electronic and optical detection systems.

An example of this technology is Dolomite's Micro Mixer chip. It is a glass device that enables the rapid and realtime analysis of fluids. Originally developed for dilution of samples prior to UV analysis, it has also been supplied to customers for nanoparticle synthesis where rapid mixing is important to achieve uniform size or surface properties of the nanoparticles.

"The Micro Mixer is a very good example of what we have been achieving," said Mark Gilligan, Managing Director of Dolomite. "Microfluidic chips, such as this, enable the mixing of chemicals in only a few milliseconds and greatly reduces sample volumes and reagent usage. The ability for companies to run reaction and analysis processes faster is helping accelerate drug discovery and will also play a important role in the development of future diagnostic equipment."

Dolomite is now considered to be a worldwide leader in Microfluidics. So much so, that in 2005 they won funding from the UK Department of Trade and Industry's Micro and Nano Technology (MNT) Manufacturing Initiative. This £2m funding, allowed Dolomite to establish excellent microfabrication facilities, with cleanrooms, precision glass processing facilities and applications laboratories.

Key to the development of the Micro Mixer is the use of microfabrication techniques capable of creating microchannels and complex structures in the glass. The main fabrication processes are photolithography, wet etching of microchannel structures, micro-drilling of fluid ports, thermal bonding and surface modification. Dolomite’s capability to undertake traditional precision glass processing techniques such as mechanical and optical polishing, grinding, cutting and dicing also enables them to extend the range of geometries that are possible.

"The challenges in the chip's manufacture include etching to two different channel depths," said Phil Homewood, Engineering Manager. "Also the alignment of features during chip assembly to micron accuracy is a complex and demanding process. Further to this, challenges at the design stage include modelling heat transfer in the chip to ensure that the temperatures of the input streams are correct prior to mixing, and also the modelling of the frictional pressure drop across the chip to meet customer flow rate requirements."