Sometimes simplicity is best. Two Northwestern University researchers have discovered a remarkably easy way to make nanofluidic devices: using paper and scissors. And they can cut a device into any shape and size they want, adding to the method's versatility.
Nanofluidic devices are attractive because their thin channels can transport ions -- and with them a higher than normal electric current -- making the devices promising for use in batteries and new systems for water purification, harvesting energy and DNA sorting.
The "paper-and-scissors" method one day could be used to manufacture large-scale nanofluidic devices without relying on expensive lithography techniques.
The Northwestern duo found that simply stacking up sheets of the inexpensive material graphene oxide creates flexible "paper" with tens of thousands of very useful channels. A tiny gap forms naturally between neighboring sheets, and each gap is a channel through which ions can flow.
Using a pair of regular scissors, the researchers simply cut the paper into a desired shape, which, in the case of their experiments, was a rectangle.
"In a way, we were surprised that these nanochannels actually worked, because creating the device was so easy," said Jiaxing Huang, who conducted the research with postdoctoral fellow Kalyan Raidongia. "No one had thought about the space between sheet-like materials before. Using the space as a flow channel was a wild idea. We ran our experiment at least 10 times to be sure we were right."
Huang is an assistant professor of materials science and engineering and the Morris E. Fine Junior Professor in Materials and Manufacturing in the McCormick School of Engineering and Applied Science.
"Many people have studied graphene oxide papers but mainly for their mechanical properties or for making graphene," Huang said. "Here we show that graphene oxide paper naturally generates numerous nanofluidic ion channels
|Contact: Megan Fellman|