APPLICATIONS OF TECHNOLOGY:
at Berkeley Lab have invented concentration and mixing elements
required to fabricate multi-functional analytical microfluidic
systems. By including a variety of polymerized monoliths with
different physical and chemical properties within the microchip
channels, custom-made analytical systems can be constructed
on a single chip.
concentration and mixing elements invented by Jean Fréchet,
Frantisek Svec, Cong Yu, and Thomas Rohr, are composed of
porous polymer monoliths located within channels that are
etched, embossed, or contoured in an inert substrate. The
channels are filled with the polymerization mixture consisting
of selected monomers, a free-radical initiator, and a porogenic
solvent. The chip is then irradiated with UV light through
a specifically designed mask. Photoinitiated polymerization
occurs within exposed regions of the device and is prevented
in areas blocked by the mask. This process is similar to photolithographic
techniques used in the electronics industry.
current microfluidic devices feature open channel architecture.
In contrast, fabricating the monolithic polymer within the
channel significantly increases the available surface area
and multiplies the number of desired interactions. Combining
these monolithic elements on a chip will enable the preparation
of tailor-made systems for detection and characterization
of microorganisms, proteins, viruses, and small molecules.
Berkeley Lab devices can be operated at flow velocities substantially
exceeding those of typical state-of-the-art analytical microfluidic
chips. For example, very good mixing has been achieved even
at a high flow velocity of 36 mm/min in a monolithic static
mixer only 5 mm long. Similarly, the enrichment of proteins
extracted from a dilute solution exceeds 1,000 times using
the simple monolithic concentrator having a volume of only
A large number of various monolithic materials differing in both porosity and chemistry can be prepared in situ via a combination of techniques including UV initiated polymerization, grafting, and post-modification. The availability of such materials and functional building blocks undoubtedly adds much to the limited array of materials and chemistries available today for analytical microfluidic chip technology, while also reducing the complexity and the manufacturing costs of the microchips.
STATUS: U.S. Patent #6,887,384. Available for licensing
REFERENCE NUMBER: IB-1739
FOR ADDITIONAL INFORMATION SEE:
Yu C., Davey M.H., Svec F., Frechet J.M., Monolithic Porous Polymer for On-Chip Solid-Phase Extraction and Preconcentration Prepared by Photoinitiated In Situ Polymerization within a Microfluidic Device, Analytical Chemistry 2001, 73, 5088-96.
Rohr T., Yu C., Davey M.H., Svec F., Frechet J.M., Porous Polymer Monoliths: Simple and Efficient Mixers Prepared by Direct Polymerization in the Channels of Microfluidic Chips, Electrophoresis 2001, 22, 3959-67