Electrical engineers at the University of California San Diego developed a technology that improves the resolution of an ordinary light microscope so that it can be used to directly observe finer structures and details in living cells. The technology relies on a specially engineered material that shortens the wavelength of light as it illuminates the sample--this shrunken light is what essentially enables the microscope to image in higher resolution.
"This material converts low resolution light to high resolution light," said Zhaowei Liu, a professor of electrical and computer engineering at UC San Diego. "It's very simple and easy to use. Just place a sample on the material, then put the whole thing under a normal microscope--no fancy modification needed."
With the technology, a conventional light microscope can be used to image live subcellular structures with a resolution of up to 40 nanometers. It comprises a microscope slide that's coated with a type of light-shrinking material called a hyperbolic metamaterial. It is made up of nanometers-thin alternating layers of silver and silica glass. As light passes through, its wavelengths shorten and scatter to generate a series of random high-resolution speckled patterns. When a sample is mounted on the slide, it gets illuminated in different ways by this series of speckled light patterns. This creates a series of low resolution images, which are all captured and then pieced together by a reconstruction algorithm to produce a high resolution image.
Liu's team is now expanding the technology to do high resolution imaging in three-dimensional space.
Photo: Electrical engineers developed a technology that improves the resolution of an ordinary light microscope so that it can be used to directly observe finer structures and details in living cells. Credit: Junxiang Zhao