EMS, MOEMs, NOEMs are Plenary Topics
SAN JOSE, Calif., Jan. 24, 2006 -- It was standing-room only for the first plenary session of Photonics West 2006 on Monday as experts in the field of MOEMS and MEMS (micro-optoelectromechanical systems and microelectromechanical systems) discussed fluidic optics, genetic engineered proteins in MEMS and tunable micro-optics.
This is the fourth year that the MOEMS-MEMS conference was held in conjunction with Photonics West. Kicking off the session was George Whitesides of Harvard University's department of chemistry and chemical biology, who discussed the use of fluids in optics. Conventional solid optics are difficult to integrate into micro- and nanosized systems, but flowing liquids are ideally suited for MEMS, and are one reason investment in microfluidics is now greater than in the rest of MEMS put together, Whitesides said. Fluidic optics can be found in things ranging from lighted fountains to liquid mirrors, liquid mirror telescopes and fluid lenses. Fluid lenses can be made very inexpensively and are used to make basic eyeglasses in Third World countries, he added
One drawback is that many microfluidic systems can only be used once to avoid cross contamination, and that can be an cost factor. Still, liquids are a class of materials largely unexploited as optical components, Whitesides said. He said he looks forward to seeing a variety of new devices resulting from research now underway.
Marc Madou, a professor of mechanical and aerospace engineering at the University of California-Irvine, spoke on the use of genetic engineered proteins in MEMS and NEMS (nanoelectromechanical systems) sensing platforms. Madou discussed how he and a team of researchers put C. elegans worms on a compact disc, fed them E. Coli bacteria and spun the discs to a force equivalent to 100 G for 24 hours. The project is funded by NASA, which will use the worms in space to study how long space flights affect humans, among other things. The researchers found that the worms, when exposed to hypergravity, exhibited changes in gene expression that seemed to help them adjust to their new environment.
Madou also gave a presentation on other projects he is working on: using E. Coli bacteria for sensing poisons in water and building a smart "pill" that can be inserted underneath a person's skin to customize drug delivery. For example, Madou said, in a diabetic patient the pill could slowly give the patient precisely the insulin dosage he needs at a particular moment. While drug delivery in tests was good over a course of 60 days, Madou said, the project involves challenges such as being able to build a biosensor that can survive in the body for more than a few weeks and building a drug delivery valve into the "pill" that doesn't stick.
Hans Zappe, professor of micro-optics in the department of microsystems technology at the University of Freiburg, Germany, presented some of the technologies and devices being employed for the fabrication of "tunable" micro-optics, i.e., liquid lenses and lens arrays, polymer membrane-based microlenses and mirrors on which the focal length, position, lens curvature or transmission wavelength can be changed.
Zappe said the technology is being developed by companies such as Varioptic and Phillips to make cell phone cameras with zoom lenses, liquid paper and lenses for endoscopy applications. Other new tunable technologies on the horizon include LCD-based tunable lasers and tunable photonic crystals, Zappe said.
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