In a technological breakthrough, Sandia researchers have developed polymer microvalves to allow fluids to be shuttled as easily in microfluidic chips as they are on a laboratory benchtop. The valves are photopatterned, cast-to-shape microscale polymer elements that can be used to isolate electric fields, and, as a consequence, locally isolate electroosmotic or electrophoretic flows. The valves can be actuated by applying pressure to move them inside a microfluidic channel in order to open and close flow pathways, isolating and manipulating the fluids of interest.
Sandia’s isolated cast-in-place microvalves feature the only architecture currently available that enables control of high-pressure (350 bar) fluid flow in microchannels, while simultaneously controlling high-voltage (1 kV). Sandia’s microfluidic polymer valves enable micro-scale systems to apply high-pressure techniques with a wide range of chemical solvents while retaining easy control of microfluidic pathways. These valves are chemically inert, preventing adsorption of species on the valve surface, and enabling low-friction valve motion.
- Effectively control both electrokinetic and high-pressure hydraulic flow.
- Greater process speeds using minuscule volumes of reagents, which saves money
- Significantly rapid response time (in milliseconds).
- Does not dissipate heat to the substrate
- Multiple microvalves may be placed on a chip for about 5 cents in materials cost
- Photopatterning the microvalves is rapid–only taking from 5 to 90 seconds.
- Valves can be operated in harsh, aggressive solvents as well as typical analytical solvents (such as water, methanol, and acetonitrile).
- No electrical power is dissipated into the fluid during valve operation.
- The microvalve dielectric strength is comparable to glass.
- Quantitative analysis is possible since common biochemical analytes neither react with nor adhere to valve surfaces.
- Miniaturization of gradient liquid chromatography analysis
- Chemical processing
- Chemical reactions
- Multi-dimensional separations
- Detection of biological and chemical agents
- Drug development
- Detection of trace chemical impurities
- Isolation, sorting, and manipulation of biological samples
|Patent Title||Patent Number||Grant Date|
|Method for producing high dielectric strength microvalves||7,022,381||04/04/2006
|Mobile monolithic polymer elements for flow control in microfluidic devices||6,988,402||01/24/2006
|Mobile monolithic polymer elements for flow control in microfluidic devices||6,952,962||10/11/2005
|Mobile monolithic polymer elements for flow control in microfluidic devices||6,782,746||08/31/2004