Judith Todd calls it a basic science project, to understand the physics of how to sustain laser plasma - a bubble of ionized gas created by absorbing the power of a laser beam or beams - and then how to use the plasma to develop novel compositions and microstructures on surfaces.

Plasmas are familiar in nature in the form of bolts of lightning or the flame of a match. "It has been shown you can use a laser plasma to make a chromium oxide coating that is ultra-hard, corrosion resistant, and wear resistant," Dr. Todd remarked about the Center’s first sponsored research project, which she heads in collaboration with Drs. Copley, Martukanitz, Merdes, Keay and Reutzel from Penn State’s Applied Research Laboratory, Dr. Semak from the Electro-Optics Center, and Professors Modest (Mechanical and Nuclear Engineering), Agrawal, Lakhtakia, Segall and Xu (Engineering Science and Mechanics), and Roy (Materials Research Institute). This is a truly multidisciplinary collaboration. The three-year project is funded by the Office of Naval Research.

The Center for MultiscaleWave-Materials Interactions is still under construction, Dr. Todd explained on a rainy day in March as we walked from her office in the Earth-Engineering Sciences Building to the Research West building, a stone’s throw away. "Part of the reason for creating this new facility is that it is open to non-US citizens," she said. "Although ARL and the Electro Optics Center have some of the best laser facilities in the country, you can’t just go in and teach students how to operate the equipment. Because of the nature of ARL’s work, visitors must be escorted within their laboratory and there are restrictions on foreign nationals. So we created this open facility to conduct both teaching and research in collaboration with ARL, EOC, the College of Engineering, and the Materials Research Institute."

What sets the Center for Multiscale Wave-Materials Interactions apart from other laser processing laboratories is their concept of using beams of different energies, such as a very high powered 10.6 micron wavelength carbon dioxide laser along with a Neodynium:YAG laser with a 1.06 micron wavelength and a very short wavelength excimer laser, which is used in semiconductor manufacturing and eye surgery, to create a new type of surface that you couldn’t get using each one by itself.

The Center is only a month old, and is still a work in progress. In one of the two labs on opposite sides of a newly painted hallway, Dr. Jian Xu, an assistant professor in Engineering Science and Mechanics, has set up a laser system and deposition chambers. In one chamber Dr. Xu makes nanoscale quantum dots - semiconductor crystals that trap electrons- then transfers the quantum dots to the second chamber and attaches them to biological molecules. His biofunctionalized quantum dots require laser processing.

Across the hall in the second lab, post-docs Puneit Dua and Ravindra Akarapu were at work on the laser plasma project. There was still equipment in boxes and not all of the lasers have been completely installed. By Materials Day in April, Dr. Todd would like to open the lab for tours and have all the equipment up and running.

Akarapu turned on one of the powerful lasers and Dua donned a welding mask and peered into the laser chamber. The concentrated laser beam shot out of a tube onto a alumina plate and within a few seconds we heard a crack and a corner of the plate shattered.

"We are doing experiments on alumina plate showing you can create plasma and redeposit species onto it," Todd explained. "We will study how species (the ionized particles, electrons, and atoms) get incorporated into plasma, and how you can feed other species into plasma to help sustain it," Todd said. "Another idea is to try and create plasma with lasers and put those together with plasma from microwaves. I don’t think anyone has put those two together before. But we’d like to try."

The U.S. lags behind Europe and Japan in laser technology. There are few places where students can be trained in the field in this country, which gives the Center the opportunity to create national leadership in laser materials research and training. "With this new center, it will be possible to span from basic research to prototype to process, plus develop students for the workforce," Todd said. "Industry, if they’re interested, can support basic research here, then take the research over the wall to ARL and develop a prototype."

Some 50 faculty in multiple colleges and units across campus and as far as Hershey have expressed interest in laser interaction with materials. Graduate education in laser materials processing is currently a five-course program from which students choose four courses for a certificate. In the next phase of course development, Todd plans to introduce a laser optics certificate option. The interest has been great enough to support the graduate program and help support the Center. "We can create a unique facility here," she said, "but we are right at the beginning."

Dr. Todd invites the materials community to tour the labs on Materials Day. Call her to set up a tour of the Center and the ARL facilities next door. She can be reached at (814) 863-0771. Judith Todd is P.B. Breneman Department Head Chair, Department of Engineering Science and Mechanics.

Credit to Penn State Materials Research Institute