First Full-Color Micro Images Produced with a 100,000-dpi Resolution
SINGAPORE—August 13, 2012—Researchers from A*STAR’s Institute of Materials Research and Engineering (IMRE) have developed a method for creating sharp, full-color images at 100,000 dpi, using metal-laced nanometer-sized structures, without the need for inks or dyes. The sample image released measured just 50 micrometers across.
This breakthrough allows coloring to be treated not as an inking process, but as a lithographic matter, which can potentially revolutionize the way images are printed and be further developed for use in high-resolution reflective color displays and high-density optical data storage.
The inspiration for the research was derived from stained glass, which is traditionally made by mixing tiny fragments of metal into the glass. It was found that nanoparticles from these metal fragments scattered light passing through the glass to give stained glass its colors. Using a similar concept with the help of modern nanotechnology tools, the researchers precisely patterned metal nanostructures, and designed the surface to reflect the light to achieve the color images.
“The resolution of printed color images very much depends on the size and spacing between individual ‘nanodots’ of color,” explained Dr Karthik Kumar, one of the key researchers involved. “The closer the dots are together—and because of their small size—the higher the resolution of the image. With the ability to accurately position these extremely small color dots, we were able to demonstrate the highest theoretical print color resolution of 100,000 dpi.”
“Instead of using different dyes for different colors, we encoded color information into the size and position of tiny metal disks,” added Dr Joel Yang, the project leader of the research. “These disks then interact with light through the phenomenon of plasmon resonances. The team built a database of color that corresponded to a specific nanostructure pattern, size and spacing. These nanostructures were then positioned accordingly.
“Similar to a child’s ‘coloring-by-numbers’ image, the sizes and positions of these nanostructures defined the ‘numbers’. But instead of sequentially coloring each area with a different ink, an ultrathin and uniform metal film was deposited across the entire image causing the ‘encoded’ colors to appear all at once, almost like magic!” continued Dr. Yang.
The researchers from IMRE had also collaborated with A*STAR’s Institute of High Performance Computing (IHPC) to design the pattern using computer simulation and modeling. IHPC’s Dr Ravi Hegde said, “The computer simulations were vital in understanding how the structures gave rise to such rich colors. This knowledge is currently being used to predict the behavior of more complicated nanostructure arrays.”
The researchers are currently working with Exploit Technologies Pte Ltd (ETPL), A*STAR’s technology transfer arm, to engage potential collaborators and to explore licensing the technology.
The Institute of Materials Research and Engineering (IMRE) is a research institute of the Agency for Science, Technology and Research (A*STAR). The Institute has capabilities in materials analysis an characterization, design and growth, patterning and fabrication, and synthesis and integration. We house a range of state-of-the-art equipment for materials research including development, processing and characterization. IMRE conducts a wide range of research, which includes novel materials for organic solar cells, photovoltaics, printed electronics, catalysis, bio-mimetics, microfluidics, quantum dots, heterostructures, sustainable materials, atom technology, etc. We collaborate actively with other research institutes, universities, public bodies, and a wide spectrum of industrial companies, both globally and locally.
The Agency for Science, Technology and Research (A*STAR) is the lead agency for fostering world-class scientific research and talent for a vibrant knowledge-based and innovation-driven Singapore. A*STAR oversees 14 biomedical sciences and physical sciences and engineering research institutes, and six consortia and centers, located in Biopolis and Fusionopolis as well as their immediate vicinity.