Announcements - constriction transducer
Today, Joel continued the work on the PMMA fiber constriction device. He completed and tested the oven containing an omega-shaped nikel-chromium alloy wire. Previously, Joel wrote the manual for the REX C100 PID temperature controller, which will be used to set up the temperature profiles around the PMMA fiber. See Joel's main document for this project.
Last week Tibi made a few constriction transducers using the fiber splicer, which are as sensitive as the joint-type. Two of them were brought to Phil's lab, and one was tested with Phil's Mosquito. They are made from 125/62.5 MM glass fiber, they have 4 constriction zones, and the tip is coated with silver using our own coating method.
We asked Hang to model the constriction transducer in order to optimize it.
Tibi and Jonathan are modifying an old optical fiber splicer to fabricate the constriction transducer. The idea is to use a platinum filament to locally heat the glass fiber very close to the melting point and pull it a few microns to create a constriction. Yassine might help with automation. More info to come. [need a very simple 3D model, need pictures of the omega-shaped filament].
During the last work party on Mars 07, 2012, we discovered that we needed to use a platinum alloy as heating element. We acquired a sample to test and it actually worked A LOT BETTER than other heating elements we tested during the previous trial. Although we did not succeed in manufacturing a constriction transducer, we advanced this project quite a bit. We also improved our setup by using some optical fiber alignment tools we manufactured from a thermoplastic polymer. See pictures taken documenting this Work. Open experimental report.
Glass optical fiber going through platinum alloy heating element
We tried two types of heating elements, tungsten and chrome-nickel. Both wires form crystals when they are heated and end up burning before the glass fiber softens enough to be pulled.
Open report : 2012 07 March Work Party - constriction transducer Tibi and Jonathan
We discovered this new possibility at the beginning of March 2012. See the source of inspiration.
glass optical fiber going through tungsten coil