Dr. Desiderio Kovar received his BS degree from UC Berkeley and his MS and Ph.D. from Carnegie Mellon University, all in Materials Science and Engineering. After completing postdoctoral training at the University of Michigan, he joined the faculty at the University of Texas at Austin. He currently is a Professor and William J. Murray Fellow in Engineering. He serves as the Graduate Advisor for the Materials Science and Engineering Program and as Faculty Director for the Longhorn Maker Studio.
Laser Ablation of Microparticle Aerosols
The Laser Ablation of Microparticle Aerosol (LAMA) process utilizes conventional, low-cost micron sized particles of virtually any inorganic material as a feedstock. The micron-sized powders are aerosolized and ablated using a pulsed laser to produce an aerosol of charged, unagglomerated nanoparticles. The nanoparticles are then accelerated through a supersonic jet to velocities of 400-1200 m/sec and impacted onto a substrate. By rastering the substrate beneath the jet nozzle, thick patterned lines can be directly written at high speeds and at room temperature. Compared to other processes advantages of the LAMA process include: 1) Nanostructured films from virtually any inorganic material can be produced 2) Highly non-equilibrium nanostructured composites can be deposited which exhibit unique and potentially advantageous properties 3) Films with tick nesses of more than 100 µm can be produced 4) Films can be patterned at high velocity and without the need for device-specific tooling 5) Since films are deposited at room temperature, polymeric substrates can be used and 6) the impaction velocities can be controlled, allowing films with a large range of densities to be produced.
Sintering of Nanoparticles and Nanoparticulate Thick Films
Due to their high surface area, high surface energy, and low melting temperature, nanoparticles can be sintered at a much lower temperature than conventional, micron-sized powder particles. This research is aimed understanding fundamental phenomena that influence the sintering of nanoparticles. The aim is to produce high quality thick films at low processing temperature by supersonic impaction of nanoparticles, followed by a low temperature anneal. Such a process would allow low cost polymeric substrates to replace ceramic and glass substrates that are currently used.
This research is performed in collaboration with the Keto, Becker, and Ferreira research groups. This material is based upon work supported by the National Science Foundation under Grant No. DMR 1006894
Microconfigured Materials with Improved Physical and Mechanical Properties
Although there is currently great interest in engineering materials at the nanoscale, there are also tremendous opportunities to influence properties by altering microscale features. Ceramic foams and honeycombs are two examples of micro-scale cellular ceramics that are used in reformers, catalytic converters, particulate filters and porous burners because of the their superior thermo-mechanical properties. We are developing methods for designing, processing, and testing of novel cellular ceramics with non-uniform cellular geometries.