Ellis Medicine

Just summarize for those who don't know, what is a laser anyway and what--?$$A laser is a device that's able to generate light in a form that essentially has one color. And it could be essentially a color that you can see or it could be a color that you can't see. What you can see is from blue to red, the colors in a rainbow. And if you look at, if you put numbers on those colors okay and we'll use microns as numbers, and if you go from .4 to say .8 microns, that's going from blue which is .4 to red which is .8. If you go below .4 you're in a region that's referred to as ultraviolet and that's sort of the color that you can't see and this is the color that everyone is concerned about you know dealing with ultraviolet coming from the sun that can cause skin cancer. If you go above .8 say to 1 and larger that's into the infrared. Lasers operate from the ultraviolet through what you can see all the way into the infrared. The uniqueness of the laser in addition to the fact that it's very, it's only of one color you know the, sort of the, the word that best describes that it's a fairly large word but it's called, it's monochromatic and that means one color. The other feature of the laser is that it's the most collimated light source known to man. If you take a flashlight and shine the flashlight over some distance, the light beam from a flashlight essentially diverges as it leaves the flashlight source.$$It gets wider and wider.$$It gets wider and wider.$$Disperses.$$And it's the same for your headlamp on your car you know, the light coming from that headlight divide, diverges out okay. The light from a laser stays very collimated. If I took a laser in this room and shined it on the wall over here and shined it on another wall the spot on the wall is almost the same size as the beam leaving the source. If you shine a laser beam from the earth to the moon, the moon is 250,000 miles away. When the laser beam gets to the moon it's going to cover an area maybe the size of this museum. And you say well that's not so good but you have to think how far did the laser travel? It traveled 250,000 miles and when it got to the moon it only illuminated a region that's the size of this museum. That's a pretty collimated light source. Being that collimated, that means that if you put this light source through a lens you're able to focus it down to a very, very small spot okay. I usually tell kids in the classroom I always ask the question, how many you know how many students have taken a magnifying glass and either ignited paper or tried to pop an ant and most of them was--raised their hand. But you're able to do that, you're able to walk around in the sun and for the most part it doesn't bother you unless you're out there too long. But if you focus the rays from the sun you know through a magnifying class it's able to focus down to a very, very small spot such that the intensity is so high that you can ignite the paper and the kids that were able to pop the ants always ask the question, why did you know why did the ant stand still? So I says--but it probably temporarily blinded it. That's what you're able to do with a laser. I've spent the last thirty-five years taking the laser beam such that if the laser beam is the size of a quarter, you know I could put something in front of the beam very quickly and it will do nothing to it. When it goes through a lens and it's focused down I can do things like what we just talked about. I can weld copper to aluminum, I can cut with it, I can heat treat with it, I can do so many different things totally non-contact which is the most exciting thing of all that you don't have to touch the part, the component, the material and you're able to impart this energy which is nothing other than light on a material in order to energize it and do some useful things.$Okay. So in 2004, you published 'Laser Hotwire Welding for Minimizing Defects' during the international congress on applications of lasers and electro optics proceedings. Right, that's (unclear).$$Okay. This hotwire laser approach you know just prior to that you know we had a patent issued in this area also and the idea, some of the materials that they use for you know building certain components for gas turbines as well as for jet engines, these materials are super-alloys. Typically when they are welded the material aspects is such that you know they will literally crack. And so we came up with this technique of this hotwire laser welding where we would essentially--it would be used to join two materials that are very difficult to weld, okay, number one. Number two, we would be able to reduce the amount of heat that would go into the welding process because we've used another means of heating the wire that we would be feeding into the joint. And we were able to demonstrate that we could weld some of these materials without cracking them okay, and without the part actually having distortion which is another issue that occurs with certain welding techniques, even with lasers. And even in the same time frame you know there was like a ten-year period where we were doing research for Lockheed Martin [American defense, technology, aerospace, advanced technology company] and when we came up with this technique the folks at NASA [National Aeronautics and Space Agency] was interested, became interested in the technique relative to the space shuttle. And the space shuttle, all the welding on the space shuttle because it's aluminum is done with another process that's called friction stir welding. And they wanted to go to, away from aluminum to some of the nickel-based alloys but they didn't have a good way at that time cause friction stir welding would not work with these nickel based alloys. And we were showing that we could use this hotwire laser process to weld the materials that they had of interest without having distortion and still maintaining the properties that they want. And I had actually visited the location where they make the fuel tanks for the shuttle down in Michoud [NASA Michoud Assembly Facility, New Orleans, Louisiana] in Louisiana and presented this technology and so forth. And we were in the process of moving forward with that and on my way home when I was in the Atlanta [Georgia] airport, that's when the Challenger [space shuttle Challenger] went down. And so I was really obviously taken back because I was, I mean I was just there where they actually made these you know fuel tanks and we were look--because where they were going was you know they wanted to--you know because the fuel tank is discarded you know with the shuttle the way it works now and they were heading in the direction of having the system to be able to come back to earth and be able to be re-used. And that was the reason for going to the new material but after that accident that approach went out, you know they just went down a different track. But that's where that, that was the potential use for that technology and it's still an area that you know we're still doing work in.