Caltech builds high-resolution microscope that can fit on a chip

Computerworld - University researchers have developed a high-resolution microscope that is small enough to sit on a computer chip.

The tiny microscope has the magnifying power of a top-quality optical microscope and is designed so scientists can use it in the field to analyze blood samples for malaria or to check water supplies for pathogens, according to the California Institute of Technology, where the research was done.

The new device, dubbed the optofluidic microscope, could be mass-produced for about $10 per microscope, officials say.

"The whole thing is truly compact. It could be put in a cell phone. And it can use just sunlight for illumination, which makes it very appealing for Third World applications," said Changhuei Yang, an assistant professor at Caltech and a developer of the device, in a statement. "Our research is motivated by the fact that microscopes have been around since the 16th century, and yet their basic design has undergone very little change and has proven prohibitively expensive to miniaturize. Our new design operates on a different principle and allows us to do away with lenses and bulky optical elements."

The microscope is built by putting a layer of metal on top of a grid of sensors -- the same sensors used in digital cameras. The university reports that developers then punched a line of holes less than one-millionth of a meter in diameter into the metal. Each hole links up to one pixel on the sensor grid. Then a tiny channel, which will carry the liquid sample to be analyzed, goes on top of the metal.

Sunlight offers enough illumination for the microscope.

Yang noted that health care workers could carry the microscopes to test people for malaria, and military medics could take disposable versions onto the battlefield.

"We could build hundreds or thousands of optofluidic microscopes onto a single chip, which would allow many organisms to be imaged and analyzed at once," said Xiquan Cui, the lead graduate student on the project, in a statement.

Yang said that the microscope chips could be used in devices that are implanted into the human body to hunt down and isolate cancer cells circulating in the blood stream.

The Defense Advanced Research Projects Agency, or DARPA, the National Science Foundation and the National Institutes of Health fund the research.

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