University of Illinois at Urbana–Champaign, Mechanical and Industrial Engineering, Ph.D. May 2002
Fluid Mechanics Lab
Fluid Mechanics II
Thermal transport in nanostructured systems; surface phonon polaritons; localized surface phonons; Fourier transform infrared (FTIR) spectroscopy, and attenuated total reflectance (ATR-FTIR); gas chromatography/flame ionization studies
We make and study subwavelength temperature sensors that respond to SiO2 polar crystal lattice vibrations caused by infrared light. This work will lead to integrated temperature sensors – thermometers that can be embedded in high temperature GaN and SiC power electronics – polar crystal materials. Infrared light waves couple to crystal lattice vibrations. The coupled vibrational properties respond to temperature changes -- much faster than acoustic and other mechanical waves, lending to the high sensitivity of this approach.
We also make and study a new type of material that passively restricts and increases how much heat flows through it. This work will lead to integrated thermal circuits, using components analogous to electronic diodes. The new material is based on nanostructured polar crystal materials that strongly transmit infrared light energy at specific temperatures.
NSF Engineering Research Center (ERC):
Engineering Research Center for Power Optimization for Electro-Thermal Systems (POETS)
E.J. Tervo, O.S. Adewuyi, J.S. Hammonds Jr., B.A. Cola, “High Polariton Thermal Conductivity in SiO2 Nanoparticle Beds”, Materials Horizons, Forthcoming (2016).
J.S. Hammonds Jr, K.A. Stancil, and C.E. Stokes, “Quality factor temperature dependence of a surface phonon polariton resonance cavity”, Applied Physics Letters, 105 (2014) 114107.
A.J. Vincent-Johnson, Y. Schwab, H.S. Mann, M. Francoeur, J.S. Hammonds Jr., and G. Scarel, “Origin of the low frequency radiation emitted by radiative polaritons excited by infrared radiation in planar La2O3 films”, Journal of Physics: Condensed Matter, 25 (2013) 035901.
O. Adewuyi, and J.S. Hammonds Jr., “Negative refraction via radiative surface phonon polaritons in a SiC based multilayer structure”, Optical Engineering, 51 (2012) 120502.
Congratulations to the Howard University Class of 2016 Mechanical Engineering Department Graduates!Read More >>
Howard University held it's annual Research Symposium April 14th, 2016 as part of its week of events for Research Week. Three students from the department of mechanical engineering presented oral and poster presentations on their current research.Read More >>