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nanotimes News in Brief
These sensors have numerous applications. For in- stance, they can be used to measure the pressure of gases. To do this, the elastomer film is stretched like a membrane across a ring. If gas exerts pressu- re on the sensor membrane, it deforms – which is detected by the sensor.
http://www.isc.fraunhofer.de
11-04 :: April/May 2011
In a single pass, the ultrathin microscope can deliver high- resolution images of objects the size of a matchbox. © Fraunhofer IOF
German Researchers at the Fraunhofer Institute for Applied Optics and Precision Engineering IOF in Jena developed a new microscope.
“Essentially, we can examine a field as large as we want,” remarks IOF group manager Dr. Frank Wippermann. “At five micrometers, the resolution is similar to that of a scanner.” There is also another benefit to the new system: With an optical length of just 5.3mm (0.209inch), the microscope is extreme- ly flat.
But how did researchers accomplish this feat? “Our ultrathin microscope consists of not just one but a multitude of tiny imaging channels, with lots of tiny lenses arrayed alongside one another. Each channel records a tiny segment of the object at the same size for a 1:1 image,” Wippermann explains. Each slice is roughly 300 x 300 µm² in size and fits seamlessly alongside the neighboring slice; a com- puter program then assembles these to generate the overall picture. The difference between this tech-
nology and a scanner microscope: all of the image slices are recorded simultaneously.
The imaging system consists of three glass plates with the tiny lenses applied to them, both on top and beneath. These three glass plates are then stacked on top of one another. Each channel also contains two achromatic lenses, so the light passes through a total of eight lenses. Several steps are involved in applying the lenses to glass substrates: first, the scientists coat a glass plate with photoresi- stant emulsion and expose this to UV light through a mask. The portions exposed to the light become hardened. If the plate is then placed in a special solution, all that remains on the surface are lots of tiny cylinders of photoresist; the rest of the coating dissolves away. Now, the researchers heat the glass plate: the cylinders melt down, leaving spherical lenses. Working from this master tool, the resear-
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