wise2004

Preparation and Characterization of Fluorescent Glass MicrobarcodesWomen in Science and Engineering, Summer Program 2004 : Preparation and Characterization of Fluorescent Glass Microbarcodes Women in Science and Engineering, Summer Program 2004 Absorption and Fluorescence How and why we see colored glass: Visible Light- every color is absorbed except the color(s) that you see. When the glass is opaque the light is reflected instead of transmitted and that is how the color is seen. Fluorescence: UV from black light source provides energy for an electron to move to a different orbital and after it stays awhile it falls back down creating visible light (fluorescence). Fluorescence is used as an amplifier in optics Optical Properties of Glass Bend light Disperse light through something like a prism Absorb/filter light Guide light (fiber optic cable) How We Made Our Own Glass Gathered and added ingredients for 150g batch. One of the following dopants Chromium (green) Cobalt (dark blue) Dysprosium (clear, fluoresced yellow) Neodymium (purple) Samarium (clear, fluoresced orange) Erbium (pink) Terbium (clear, fluoresced teal) Europium (clear, fluoresced red) Uranium (light yellow, fluoresced lime green) Mixed all ingredients together. Placed mixed ingredients into crucible. Placed crucible into furnace. Furnace heated to 1200ºC and the glass allowed to melt. Charged the glass by adding more batch. Poured glass into graphite molds. Molten glass was annealed. Blowing Glass There are two types of pipes: -Blow Pipe (hollow inside) -Punty (piece of stainless steal) Making a flower: The blow pipe first has to be heated in the glory hole (big furnace). The pipe should glow light red or orange to indicate it is warm and will not take all of the heat out of the glass. The glass is put onto the blow pipe by twirling it into glass that is in the bottom of the melting furnace. A little piece of glass will attach to the end of the blow pipe since both the pipe and the glass are hot, causing it to stick to each other. The clear glass is shaped by rolling it on a table. In order to put color into the flower, the top of the blow pipe with glass is laid in glass powder. The color only needs to be on the inside. Next the blow pipe is stuck back into the glory hole and heated up until they melt all together. In order to shape the flower it is taken over the the bench. While twirling the blow pipe, you will use tweezers dipped in water. Also, your hands will be dipped into water. Flower will start to form as it cools. You pull the flower in order to get the stem portion of the flower. Drops of water are put at the end to break the flower off. Then the flower is put into the annealing furnace. Making a paper weight: The first steps are very similar to making a flower except the punty is used. The paper weight can be shaped it into whatever shape you want and the color is added by pieces of glass as above. After the color clear glass is put on top. When the paper weight is almost finished a you form a jackline which looks like an hour glass shape back by the end of the Punty and then crack off the paper weight. To finish the paper weight you put a couple drops of water right on hour glass crack. When the paper weight is cooled down you put it into the annealing furnace. Background Information Characteristics of glass: Brittle Common glasses are transparent 72% sand (Silicon Dioxide-SiO2 or silica) Solid but has the atomic structure of a liquid because it is a “super-cooled” liquid Low thermal expansion and low thermal conductivity Non-crystalline solid Four main ways to make glass and examples: Blown- bottles, light bulbs, art, drinking glasses Floated- flat sheets (windows) Drawn- ribbons, fibers (woven into thin sheets) Cast/Pressed- eye glasses, kitchenware Barcodes How they are made: -We bonded several fluorescent glasses and stretched the glass similar to when we made our own glass pieces. Uses: Bombs- security Real barcodes Identification mechanism Drug screening Industry: -They use the fiber draw tower and pull strands of glass to a width of 5μm (20 strands can fit across one strand of human hair). Penn State Instructors and Assistants: Dr. John Hellman, Dr. David Green, Dr. Carlo Pantano Jane Howell, Rob Schaut, Joe Ryan, Elam Leed, and Andrea Fortunato WISE 2004 Students: Lauren Kirkland Jamie Svoboda Helen Larsen Giovanna Tyler Lindsey Mason Emily Wible Jessica Serra Holly Yauch Barcodes under visible light Barcodes under a black light Conclusions Fluorescent glasses are easily manufactured and cheap. They have many uses besides for the enjoyment of the audience. The fluorescence from the glasses can be used to make barcodes which can be used in many different applications. Dysprosium Europium Samarium Terbium Uranium