July R&D Round UpJuly 11, 2008 By: Melanie Martella, Sensors
This month, pressure sensing contact lenses, 3D nanostructures in magnetic materials, a robot for pipeline checking, and pocket-sized nuclear magnetic resonance imaging.
Glaucoma Testing in a Lens
For sufferers of glaucoma (retinal damage caused by an intra-ocular pressure that's too high AKA optical hypertension), monitoring the disease requires frequent trips to the opthalmologist. However, Researchers Hailin Cong and Tingrui Pan at the University of California - Davis have created a contact lens with embedded pressure sensors that could be used to monitor such conditions. Although the lens itself is impressive enough, the technique they used to achieve it is more so. Contact lenses are made of a polymer called polydimethylsulfoxane (PDMS), which is (currently) cast in molds to create the needed shape. However, the range of shapes achievable is limited by the molds. The researchers discovered that, by adding a chemical to the polymer, they could cause the mixture to polymerize when exposed to UV light. Create an appropriate mask, zap the doped mixture with UV light, and wherever the light hits the material will polymerize, allowing them to create features as small as 10 nm. By adding silver to the mix, Cong and Pan could create conductive paths in the material.
Those busy people at NIST have discovered a way to build complex, 3D nanoscale structures out of magnetic materials paving the way for novel 3D MEMS actuators and inductors. The technique adapts an existing semiconductor manufacturing method for complex 3D copper interconnects called Damascene metallization. During the traditional approach, trenches cut in the silicon are filled with copper and the surface is ground down to reveal the copper paths before additional layers are added. The NIST researchers have figured out how to do the same thing but with ferromagnetic materials rather than copper.
Robots in the Pipes
Scandinavian research organization SINTEF are applying their knowledge of snake-inspired robots to develop one that can navigate industrial piping systems, including vertical pipe runs. Science Daily's "The Robot That Climbs In The Pipe" has a longer description of the research, including the (to me) fascinating fact that they're using a LEGO Mindstorm robot (with an attached camera) to collect data in order to train the robot's vision system. While this project is still in the design stage, if they can bring their idea to reality, pipeline monitoring could get a lot easier.
It's not just consumer electronics that are getting smaller, courtesy of a collaboration between Magritek and the Fraunhofer Institute for Biomedical Technology Engineering's Magnetic Resonance working group. The researchers have created pocket-sized magnetic resonance scanners that have potential applications ranging from analyzing arctic ice cores to checking the fat content of cheese during processing. Rather than use the huge cooled superconducting magnets required for medical MRI scanners, the team have used extra-strong permanent magnets arranged so that their field lines overlap to create a homogeneous field. This has allowed the researchers to drastically shrink the size of the devices and make them portable.
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