AVS 61st International Symposium & Exhibition
    Nanometer-scale Science and Technology Monday Sessions
       Session NS+SE-MoM

Invited Paper NS+SE-MoM8
Effects of Chemical Bonding on Heat Transfer Across Interfaces

Monday, November 10, 2014, 10:40 am, Room 304

Session: Delivering Energy and Mass at the Nanoscale 
Presenter: Paul Braun, University of Illinois at Urbana-Champaign
Authors: P. Braun, University of Illinois at Urbana-Champaign
M. Losego, University of Illinois at Urbana-Champaign
M. Grady, University of Illinois at Urbana-Champaign
N. Sottos, University of Illinois at Urbana-Champaign
D.G. Cahill, University of Illinois at Urbana-Champaign
Correspondent: Click to Email
Interfaces often dictate heat flow in micro- and nanostructured systems. However, despite the growing importance of thermal management in micro- and nanoscale devices, a unified understanding of the atomic-scale structural features contributing to interfacial heat transport does not exist. Herein, we experimentally demonstrate a link between interfacial bonding character and thermal conductance at the atomic level. Our experimental system consists of a gold film transfer-printed to a self-assembled monolayer (SAM) with systematically varied termination chemistries. Using a combination of ultrafast pump–probe techniques (time-domain thermoreflectance, TDTR, and picosecond acoustics) and laser spallation experiments, we independently measure and correlate changes in bonding strength and heat flow at the gold–SAM interface. For example, we experimentally demonstrate that varying the density of covalent bonds within this single bonding layer modulates both interfacial stiffness and interfacial thermal conductance. We believe that this experimental system will enable future quantification of other interfacial phenomena and will be a critical tool to stimulate and validate new theories describing the mechanisms of interfacial heat transport. Ultimately, these findings will impact applications, including thermoelectric energy harvesting, microelectronics cooling, and spatial targeting for hyperthermal therapeutics.