Specialized microscopes that can image individual atoms have opened up the nanometer-scaled world to scientists. But existing scanning probe microscopes, which move an extremely fine tip along a surface, are able only to map the topography of the atomic world; they cannot easily distinguish between different compounds.
To overcome this chemical blindness, scientists at Max Planck Institute in Martinsried, Germany, have built a scanning microscope able to perform infrared (IR) spectroscopy-a common analytical technique that exploits the characteristic IR absorption of different compounds. The tip of the microscope is positioned just above the sample and is illuminated by an infrared beam; the tip then senses the IR absorption of the sample beneath it. The Max Planck researchers have identified different polymers with a resolution of 100 nanometers, and hope to achieve resolution as fine as 10 nanometers.