This EArly-concept Grant for Exploratory Research (EAGER) project is to develop high performance bulk thermoelectric materials by manipulating their structures at the meso-, micro-, and nano-scale. Achieving a broad range of length scales in the structure of thermoelectric materials is expected to maximize phonon scattering, which will in turn maximize the performance of thermoelectric materials due to the depletion of phononic (or lattice) thermal conduction. Here, the novel idea is to utilize continuum-level fluid mechanics (layering technique) for designing meso/micro-scale structures while creating micro/nano-scale structures with self-assembly and eutectic growth. Through meso-/micro-scale layering and structuring with liquid phase precursors, the size and distribution of nanoparticle inoculants will be manipulated to control the heterogeneous nucleation and solid phase formation at micro-/nano-scales. This new out-of-the-box but high-risk approach integrating fluid mechanics into materials science/engineering will provide new insight and research direction.
Thermoelectric energy conversion systems offer an excellent strategy for improving sustainability of our electric power base by scavenging waste heat from various power consuming systems including automobiles and power plants or for providing effective compact cooling for computers and electronic devices with robustness and silence. The research will provide rational and novel methodologies of improving their efficiency by modifying material structures. In addition, research outcomes include crucial knowledge for fully utilizing nanoparticles by solving one of the major hurdles, nanoparticle aggregation. This new approach combining continuum level fluid mechanics and controlling structures down to nanoscale related to material science/engineering may bring subsequent research related to rational design of multi-scale structured materials. The research also include training of Ph.D students with experience in interdisciplinary collaborative research; broadening participation of undergraduate students belonging to underrepresented groups through the NSF-funded Louis Stokes Alliance for Minority Participation at Texas A&M University and the Center for Enhancement of Engineering Diversity at Virgina Tech; and integrating nanoscale thermal transport phenomena into undergraduate/graduate courses.
