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Brad Petersen
Director of
Communications
1066 ECE Building
306 N. Wright Street
Urbana, IL 61801
Phone: (217) 244-6376
bradp@illinois.edu

Contact Info

Meg Dickinson
Communications Specialist
1068 ECE Building
306 N. Wright Street
Urbana, IL 61801
Phone: (217) 300-6664
megd@illinois.edu

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Recent News

Illinois wins $1.5 million NSF 'Data Infrastructure Building Blocks' grant to accelerate materials-to-device processes

Illinois wins $1.5 million NSF 'Data Infrastructure Building Blocks' grant to accelerate materials-to-device processes

It can take 20 years between the creation of a new material in the laboratory and the fabrication of next-generation devices that employ the material.

Semiconductor membrane mimics biological behavior of ion channels

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By James E. Kloeppel, News Buereau
July 23, 2007

  • A semiconductor membrane designed by ECE Illinois researchers could offer more flexibility and better electrical performance than biological membranes.
  • Built from thin silicon layers doped with different impurities, the solid-state membrane also could be used in applications such as single-molecule detection, protein filtering, and DNA sequencing.
  • Funding was provided by the National Science Foundation and the National Institutes of Health.
Jean-Pierre  Leburton
Jean-Pierre Leburton

A semiconductor membrane designed by ECE Illinois researchers could offer more flexibility and better electrical performance than biological membranes. Built from thin silicon layers doped with different impurities, the solid-state membrane also could be used in applications such as single-molecule detection, protein filtering, and DNA sequencing.

"By creating nanopores in the membrane, we can use the membrane to separate charged species or regulate the flow of charged molecules and ions, thereby mimicking the operation of biological ion channels," said lead researcher Jean-Pierre Leburton, the Stillman Professor of Electrical and Computer Engineering.

Leburton, with Beckman Institute postdoctoral research associate Maria Gracheva and ECE graduate student Julien Vidal, simulated the operation of the semiconductor membrane at a number of electrostatic potentials. They report their findings in a paper accepted for publication in the journal Nano Letters, and posted on the journal's Web site.

In the researchers’ model, the nanopore-membrane structure is made of two layers of silicon, each 12 nanometers thick, with opposite (n- and p-) doping. The electrostatic potential is positive on the n-side and negative on the p-side of the membrane.

This contour plot represents the net charge distribution in the electrolyte and the semiconductor membrane. The left panel shows positive charge and the right panel shows negative charge.
This contour plot represents the net charge distribution in the electrolyte and the semiconductor membrane. The left panel shows positive charge and the right panel shows negative charge.

The nanopore has an hourglass shape, with a neck one nanometer in diameter and openings on each side of the membrane six nanometers in diameter. The "size" of the nanopore can be changed by changing the electrostatic potential around it.

By controlling the flow of ions, the artificial nanopore offers a degree of tunability not found in biological ion channels, said Leburton, who also is a researcher at the University’s Beckman Institute, Coordinated Research Laboratory, and Micro and Nanotechnology Laboratory.

In addition to serving as a substitute for biological ion channels, the solid-state nanopore and membrane could be used in other applications, including sequencing DNA.

"Using semiconductor technology to sequence the DNA molecule would save time and money," Leburton said. "By biasing the voltage across the membrane, we could pull DNA through the nanopore. Since each base pair carries a different electrical charge, we could use the membrane as a p-n junction to detect the changing electrical signal."

Funding was provided by the National Science Foundation and the National Institutes of Health.

Editor's note: media inquiries should be directed to Brad Petersen, Director of Communications, at bradp@illinois.edu or (217) 244-6376.

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