Fluidigm’s Integrated Fluidic Circuit
In the 1970s engineers recognized that the principles that spawned the semiconductor industry could be applied to liquids for the life science industry. Microfluidic devices could incorporate and miniaturize complex fluid-handling steps without loss of reliability.
Some developers tried to use silicon for making microfluidic devices based on electro-osmotic flow, but this method turned out to be ineffective at regulating the mixing of fluids, without complicated engineering solutions that were difficult to reproduce for high-volume applications.
In 1998, Dr. Stephen Quake and his group at the California Institute of Technology solved this problem through the development of a fabrication process called Multilayer Soft Lithography (MSL®). The process uses rubber that deflects under pressure to create an effective seal. More importantly, the structures made from this material are so small that tens of thousands of them can be integrated into a dense network of channels for regulating solutions on a micro-, nano-, or even picoliter-scale. The elegantly simple valve is the foundation of Fluidigm’s various integrated fluidic circuits. The valve is trademarked as the NanoFlex valve.
A simple, yet efficient design is the hallmark of the NanoFlex™ valve. It consists of a membrane that deflects under pressure to pinch off the flow of fluids in a microchannel. The valve is made from two separate layers of elastomeric rubber that have been placed on a micro-machined mold. By bonding the layers together, the recesses form channels and chambers in a rubber chip.
When pressurized gas is applied to the channels in one layer of the chip, the rubber deflects at precisely the intersection of the channels in the bottom layer. This constitutes a simple, effective valve. View animation.
The Features and Benefits of Fluidigm’s Integrated Fluidic circuit Technology
Although liquid-handling robots have afforded gains in productivity for the life science industry, their value diminishes as the demand for greater throughput grows. Robots' bulk, complexity, and cost cannot match the elegant simplicity, density, and cost-effectiveness of Fluidigm’s integrated fluidic circuits (IFCs). Benefits of IFC technology include:
- Microscopic. Nanoflex valves are so small a single IFC can accommodate hundreds of thousands of reaction wells.
- Precise. In IFCs, reaction volumes are controlled by the geometries of the chamber, eliminating the variability associated with using liquid-dispensing instrumentation.
- Versatility. Unlike biochips that are pre-spotted at the factory, IFCs are loaded with any assay of choice in the researcher’s laboratory. Researchers can develop their own assays or purchase pre-optimized reagents from Fluidigm.
- Direct viewing of results. IFCs are made of optically-clear elastomer. Reactions can be observed directly as they occur.
- Gentle on living cells. Living cells within Fluidigm’s chips are exposed to a programmable diffusive flow, a more hospitable environment than is found in the wells of microplates.
- Sample- and reagent-efficiency. In IFCs, experiments are conducted using hundreds-of-times less sample and reagent compared to requirements for micro-plates. This is possible because IFCs are precisely fabricated in microscopic dimensions with extremely accurate volumetric chambers that are filled with the liquids.