Researchers at Caltech have created a high-resolution, lens-free microscope that fits on a dime-size chip, and this tiny $10 microscope could broaden access to imaging technology — or be incorporated into large arrays, enabling high-throughput imaging in biology labs:
The Caltech device uses a system of tiny fluid channels called microfluidics to direct cells and even microscopic animals over a light-sensing chip. The chip, an off-the-shelf sensor identical to those found in digital cameras, is covered with a thin layer of metal that blocks out most of the pixels. A few hundred tiny apertures punched in the metal along the fluid channel let light in. As the sample flows through the microscope, each aperture captures an image. One version of the microscope uses gravity to control the flow of the sample across the apertures. Another version, which allows for much better control, uses an electrical potential to drive the flow of cells.The 100 to 200 images are then combined using simple image-processing software. The processing power in a PDA is more than sufficient to perform the calculations, says Caltech engineer Changhuei Yang, who designed the microscope. The microscope must be illuminated from above, but sunlight is sufficient. The resolution of the microscope is similar to that of a conventional light microscope — about one micrometer — and is limited by the size of the apertures.