Nano-Material and Structural Engineering for Thermal Highways
Abstract
The AOARD-KRF "thermal management" project has led to several developments and breakthroughs driven by collaborative efforts between the Korean groups (Seoul National University and KRISS) and the group at Brown University. Two main objectives were set for the project: improvement of thermoelectric efficiency and demonstration of "thermal diodes" with heat-flow rectification. Both objectives were successfully met, and in fact, exceeded. One breakthrough - thermal-voltage imaging with unprecedented atomic resolution that exceeds classical limits is particularly noteworthy. It was unanticipated at the start but propelled by growing interests arising from this effort. It will likely extend its impact beyond thermal management into basic sciences for years to come. Several strategies for improving thermal functionality in electronic materials were implemented via AIPEL patterning, AAO-templated nanomesh formation and atomic-layered doping. Thermal rectification effects have been ascertained by engineering into the structure phase-changing and strongly temperature dependent materials. An ultrathin (~40nm) film that is infrared (heat) reflecting, light-transmitting (>90%), highly conductive (~1000 S/cm) and also EMI-shielding (>20dB) stands out as another example outcome of the exploration of an atomic-layer engineering approach. It could lead to defense and civilian applications in near term. A novel concept of self-regulated cooling, inspired by nature (e.g. human skin sweating), was implemented, tested, and proven to be effective. This success, however still preliminary, opens a pathway to explorations of wearable, scalable, distributed, self-powered cooling and temperature regulation, as well as to its underlying science of phase-transitions in nano-capillary fluidics. Details of key findings have been documented in some 10 publications, including one to appear in Nature Materials, one patent application, and several more to follow.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 14, 2013
- Accession Number
- ADA586780
Entities
People
- Ho-ki Lyeo
- Jimmy Xu
- Ki-Bum Kim
Organizations
- Seoul National University