To build the memory chip, the researchers first etched 400 parallel wires, each less than a millionth of an inch wide and separated by about 1/750,000th of an inch from its neighbors. On top of the wires, they deposited a layer of the molecular switches, the dumbbells standing vertically, and then a second set of 400 wires turned 90 degrees to the first set. Each crossing point between two perpendicular wires, with about 100 of the molecular switches wedged in between, is the storage location of one bit of information.

Current methods for drawing circuits on silicon will bump against the laws of physics, because the circuit components will be much smaller than the wavelength of light used to draw them. That has led researchers to look for alternative approaches to build molecular-size electronics. Most are still building circuits containing only a handful of components compared to the 160,000 in the new memory chip. That suggests the new process Dr. Heath and Dr. Stoddart developed can be scaled up to a viable manufacturing process, said Vivek Subramanian, a professor of electrical engineering and computer sciences at the University of California, Berkeley.

“This is sort of the capstone in that they’ve pulled all this together,” said Dr. Subramanian, who was not involved in the research.

Not everything works yet. When the researchers tested a small portion of the chip, they found that only 30 percent of the bits actually worked. But it is possible to use only the working parts of the chip, and the researchers successfully wrote and read information to those parts, though even there the success was temporary. The switches routinely broke after being flipped about 10 times.

The researchers readily admit that their chip is a demonstration, not imminent technology.

“We’re just happy it works,” Dr. Heath said.