Research & Development World

  • R&D World Home
  • Topics
    • Aerospace
    • Automotive
    • Biotech
    • Careers
    • Chemistry
    • Environment
    • Energy
    • Life Science
    • Material Science
    • R&D Management
    • Physics
  • Technology
    • 3D Printing
    • A.I./Robotics
    • Software
    • Battery Technology
    • Controlled Environments
      • Cleanrooms
      • Graphene
      • Lasers
      • Regulations/Standards
      • Sensors
    • Imaging
    • Nanotechnology
    • Scientific Computing
      • Big Data
      • HPC/Supercomputing
      • Informatics
      • Security
    • Semiconductors
  • R&D Market Pulse
  • R&D 100
    • Call for Nominations: The 2025 R&D 100 Awards
    • R&D 100 Awards Event
    • R&D 100 Submissions
    • Winner Archive
    • Explore the 2024 R&D 100 award winners and finalists
  • Resources
    • Research Reports
    • Digital Issues
    • R&D Index
    • Subscribe
    • Video
    • Webinars
  • Global Funding Forecast
  • Top Labs
  • Advertise
  • SUBSCRIBE

“White Graphene” Structures Take the Heat

By R&D Editors | July 15, 2015

A 3D structure of hexagonal boron nitride sheets and boron nitride nanotubes could be a tunable material to control heat in electronics, according to researchers at Rice University. Image: The Shahsavari GroupThree-dimensional structures of boron nitride might be the right stuff to keep small electronics cool, according to scientists at Rice University.

Rice researchers Rouzbeh Shahsavari and Navid Sakhavand have completed the first theoretical analysis of how 3D boron nitride might be used as a tunable material to control heat flow in such devices.

Their work appears in the most recent issue of the American Chemical Society journal Applied Materials and Interfaces.

In its two-dimensional form, hexagonal boron nitride (h-BN), aka white graphene, looks just like the atom-thick form of carbon known as graphene. One well-studied difference is that h-BN is a natural insulator, where perfect graphene presents no barrier to electricity.

But like graphene, h-BN is a good conductor of heat, which can be quantified in the form of phonons. (Technically, a phonon is one part — a “quasiparticle” – in a collective excitation of atoms.) Using boron nitride to control heat flow seemed worthy of a closer look, Shahsavari says.

“Typically in all electronics, it is highly desired to get heat out of the system as quickly and efficiently as possible,” he says. “One of the drawbacks in electronics, especially when you have layered materials on a substrate, is that heat moves very quickly in one direction, along a conductive plane, but not so good from layer to layer. Multiple stacked graphene layers is a good example of this.”

Heat moves ballistically across flat planes of boron nitride, too, but the Rice simulations showed that 3D structures of h-BN planes connected by boron nitride nanotubes would be able to move phonons in all directions, whether in-plane or across planes, Shahsavari says.

The researchers calculated how phonons would flow across four such structures with nanotubes of various lengths and densities. They found the junctions of pillars and planes acted like yellow traffic lights, not stopping but significantly slowing the flow of phonons from layer to layer, Shahsavari says. Both the length and density of the pillars had an effect on the heat flow: more and/or shorter pillars slowed conduction, while longer pillars presented fewer barriers and thus sped things along.

While researchers have already made graphene/carbon nanotube junctions, Shahsavari believes such junctions for boron nitride materials could be just as promising. “Given the insulating properties of boron nitride, they can enable and complement the creation of 3D, graphene-based nanoelectronics.

“This type of 3D thermal-management system can open up opportunities for thermal switches, or thermal rectifiers, where the heat flowing in one direction can be different than the reverse direction,” Shahsavari says. “This can be done by changing the shape of the material, or changing its mass — say one side is heavier than the other — to create a switch. The heat would always prefer to go one way, but in the reverse direction it would be slower.”

Shahsavari is an assistant professor of civil and environmental engineering and of materials science and nanoengineering. Sakhavand is a former graduate student at Rice.

The National Science Foundation and the Rice Department of Civil and Environmental Engineering supported the research. The researchers used the National Science Foundation-supported DAVinCI supercomputer administered by Rice’s Ken Kennedy Institute for Information Technology. They also used computing resources supported by the National Institutes of Health, IBM, CISCO, Qlogic, and Adaptive Computing.

Release Date: July 15, 2015
Source: Rice University 

Related Articles Read More >

The emerging materials shaping next-generation semiconductor electronics
24 R&D trends that redefined 2024
Graphene-based flowmeter sensor measures nano-rate fluid flows, Part 3: The sensor
Graphene-based flowmeter sensor measures nano-rate fluid flows, Part 2: The graphene context
rd newsletter
EXPAND YOUR KNOWLEDGE AND STAY CONNECTED
Get the latest info on technologies, trends, and strategies in Research & Development.
RD 25 Power Index

R&D World Digital Issues

Fall 2024 issue

Browse the most current issue of R&D World and back issues in an easy to use high quality format. Clip, share and download with the leading R&D magazine today.

Research & Development World
  • Subscribe to R&D World Magazine
  • Enews Sign Up
  • Contact Us
  • About Us
  • Drug Discovery & Development
  • Pharmaceutical Processing
  • Global Funding Forecast

Copyright © 2025 WTWH Media LLC. All Rights Reserved. The material on this site may not be reproduced, distributed, transmitted, cached or otherwise used, except with the prior written permission of WTWH Media
Privacy Policy | Advertising | About Us

Search R&D World

  • R&D World Home
  • Topics
    • Aerospace
    • Automotive
    • Biotech
    • Careers
    • Chemistry
    • Environment
    • Energy
    • Life Science
    • Material Science
    • R&D Management
    • Physics
  • Technology
    • 3D Printing
    • A.I./Robotics
    • Software
    • Battery Technology
    • Controlled Environments
      • Cleanrooms
      • Graphene
      • Lasers
      • Regulations/Standards
      • Sensors
    • Imaging
    • Nanotechnology
    • Scientific Computing
      • Big Data
      • HPC/Supercomputing
      • Informatics
      • Security
    • Semiconductors
  • R&D Market Pulse
  • R&D 100
    • Call for Nominations: The 2025 R&D 100 Awards
    • R&D 100 Awards Event
    • R&D 100 Submissions
    • Winner Archive
    • Explore the 2024 R&D 100 award winners and finalists
  • Resources
    • Research Reports
    • Digital Issues
    • R&D Index
    • Subscribe
    • Video
    • Webinars
  • Global Funding Forecast
  • Top Labs
  • Advertise
  • SUBSCRIBE