Monday, November 27, 2006

"MEMS: Microfluidics is beginning to clear the lab"

While microfluidic devices that enable such popular applications as laboratories-on-a-chip are still mostly in the research stage, some companies are making strides toward commercial-grade applications. Microfluidics enables chips to pipe fluids around their surfaces in micron-sized channels, either to perform a test hitherto only possible in a lab, or just to remove heat and cool a chip. The premiere application--labs-on-a-chip--enables battery-powered sensor-based devices to quickly detect trace amounts of almost any substance. What are the blocks to volume production today? That depends on whom you ask, but three reasons loom large--a lack of chip-sized microfluidic pumps; a mismatch between micro-sized fluidic channels and the rest of a lab's equipment; and a lack of standards for interoperability among labs-on-a-chip from rival manufacturers. The first problem--a lack of chip-sized microfluidic pumps--was addressed recently by two new architectures for micropumps (see page 34). One from the University of Utah uses a "squeeze bottle" approach that houses the micropumps in a disposable polymer test card. The other from the Massachusetts Institute of Technology (Cambridge, Mass.) uses a novel photolithographic technique to gain electronic control over micropumping.