PC chips that ‘grow’ themselves

Scientists in Israel have successfully used strands of DNA to create molecular sized circuits to make tiny transistors that build themselves.

“What we’ve done is to bring biology to self-assemble an electronic device in a test tube,” Dr. Erez Braun, a physicist at the Technion-Israel Institute of Technology in Haifa, Israel, told the New York Times.

The scientists made transistors out of carbon nanotubes, cylindrical molecules that are about one ten-millionth of an inch in diameter and resemble rolled-up chicken wire.

The new technique takes advantage of a biological process known as recombination, where a segment of DNA is swapped out for a nearly identical piece. The cell uses recombination to repair damaged DNA and to swap genes. A special protein helps connect the replacement DNA to the desired location.

By attaching a nanotube to the protein, the nanotube moves to an exact location along the DNA strand.

“The DNA serves as a scaffold, a template that will determine where the carbon nanotubes will sit,” Braun said. “That’s the beauty of using biology.”

The scientists then coated the DNA with gold, producing a simple electronic device consisting of the nanotube connected to gold wires at each end. Current through the nanotube could be switched on or off by applying an electric field — the definition of a transistor.

Source: United Press International