As a result, the researchers were able to create devices with "funnels" many micrometers wide and about a micrometer deep that tapered down to nanochannels with depths as shallow as 7 nanometers—approximately 1,000 times smaller in diameter than a red blood cell. The nanoglassblown chambers soon showed distinct advantages over their planar predecessors.
"In the past, for example, it was difficult to get single strands of DNA into a nanofluidic device for study because DNA in solution balls up and tends to bounce off the sharp edges of planar channels with depths smaller than the ball," says Cornell's Elizabeth Strychalski. "The gradually dwindling size of the funnel-shaped entrance to our channel stretches the DNA out as it flows in with less resistance, making it easier to assess the properties of the DNA," adds NIST's Samuel Stavis.
Future nanoglassblown devices, the researchers say, could be fabricated to help sort DNA strands of different sizes or as part of a device to identify the base-pair components of single strands. Other potential applications of the technique include the manufacture of optofluidic elements—lenses or waveguides that could change how light is moved around a microchip—and rounded chambers in which single cells could be confined and held for culturing. ###
This work was supported in part by Cornell's Nanobiotechnology Center, part of the National Science Foundation's Science and Technology Center Program. It was performed while Samuel Stavis held a National Research Council Research Associateship Award at NIST.
* E.A. Strychalski, S.M. Stavis and H.G. Craighead. Non-planar nanofluidic devices for single molecule analysis fabricated using nanoglassblowing. Nanotechnology, Posted online the week of June 15, 2008.
Contact: Michael E. Newman firstname.lastname@example.org 301-975-3025 National Institute of Standards and Technology (NIST)
Tags: Nano or Nanotechnology and Nanotech