How Can We Design Electronic Devices That Don’t Overheat?
November 14, 2018 | Stanford UniversityEstimated reading time: 2 minutes
You’ve felt the heat before — the smartphone that warms while running a navigation app or the laptop that gets too hot for your lap.
The heat produced by electronic devices does more than annoy users. Heat-induced voids and cracking can cause chips and circuits to fail.
Now a Stanford-led engineering team has developed a way to not only manage heat, but help route it away from delicate devices. Writing in Nature Communications, the researchers describe a thermal transistor — a nanoscale switch that can conduct heat away from electronic components and insulate them against its damaging effects.
“Developing a practical thermal transistor could be a game changer in how we design electronics,” said senior author Kenneth Goodson, a professor of mechanical engineering.
Researchers have been trying to develop heat switches for years. Previous thermal transistors proved too big, too slow and not sensitive enough for practical use. The challenge has been finding a nanoscale technology that could toggle on and off repeatedly, have a large hot-to-cool switching contrast and no moving parts.
Aided by electrical engineer Eric Pop and materials scientist Yi Cui, Goodson’s team overcame these obstacles by starting with a thin layer of molybdenum disulfide, a semiconducting crystal that is made up of layered sheets of atoms. Just 10 nanometers thick and effective at room temperatures, this material could be integrated into today’s electronics, a critical factor to making the technology practical.
In order to make this heat-conducting semiconductor into a transistor-like switch, the researchers bathed the material in a liquid with lots of lithium ions. When a small electrical current is applied to the system, the lithium atoms begin to infuse into the layers of the crystal, changing its heat-conducting characteristics. As the lithium concentration increases, the thermal transistor switches off. Working with Davide Donadio’s group at the University of California, Davis, the researchers discovered that this happens because the lithium ions push apart the atoms of the crystal. This makes it harder for the heat to get through.
Aditya Sood, a postdoctoral scholar with Goodson and Pop and co-first author on the paper, likened the thermal transistor to the thermostat in a car. When the car is cold, the thermostat is off, preventing coolant from flowing, and the engine retains heat. As the engine warms, the thermostat opens and coolant begins to move to keep the engine at an optimal temperature. The researchers envision that thermal transistors connected to computer chips would switch on and off to help limit the heat damage in sensitive electronic devices.
Besides enabling dynamic heat control, the team’s results provide new insights into what causes lithium ion batteries to fail. As the porous materials in a battery are infused with lithium, they impede the flow of heat and can cause temperatures to shoot up. Thinking about this process is crucial to designing safer batteries.
In a more distant future the researchers imagine that thermal transistors could be arranged in circuits to compute using heat logic, much as semiconductor transistors compute using electricity. But while excited by the potential to control heat at the nanoscale, the researchers say this technology is comparable to where the first electronic transistors were some 70 years ago, when even the inventors couldn’t fully envision what they had made possible.
“For the first time, however, a practical nanoscale thermal transistor is within reach,” Goodson says.
Suggested Items
IDTechEx Examines the Opportunities for Wearables in Digital Health
04/19/2024 | IDTechExIDTechEx’s report, “Digital Health and Artificial Intelligence 2024-2034: Trends, Opportunities, and Outlook”, covers this ongoing trend in the consumer health wearables market and includes analysis of the opportunities and roadmap for biometric monitoring.
Absolute EMS Champions Collaboration Between Humans and Robots in Modern Manufacturing
04/19/2024 | Absolute EMS, Inc.Absolute EMS, Inc., an award-winning EMS provider of turnkey contract manufacturing services, offers a perfect factory environment that seamlessly blends robotic automation with human expertise.
ZESTRON Welcomes Whitlock Associates as New Addition to their Existing Rep Team in Florida
04/19/2024 | ZESTRONZESTRON, the leading global provider of high-precision cleaning products, services, and training solutions in the electronics manufacturing and semiconductor industries, is thrilled to announce the addition of Whitlock Associates to its esteemed network of sales representatives.
IPC Bestows Posthumous Hall of Fame Award to Industry Icon Michael Ford
04/18/2024 | IPCIPC honored the late Michael Ford, Aegis Software, for his extraordinary contributions to the global electronics manufacturing industry with the IPC Raymond E. Pritchard Hall of Fame Award at IPC APEX EXPO 2024. IPC’s most prestigious honor, the Hall of Fame Award is given to individuals who have provided exceptional service and advancement to IPC and the electronics industry. Ford, an industry leader and valued IPC volunteer, died suddenly in January 2024.
SEMI Applauds U.S. Chips Act Award for Samsung Electronics Facilities to Strengthen Domestic Semiconductor Supply Chain
04/17/2024 | SEMISEMI, the industry association serving the global electronics design and manufacturing supply chain, applauded the United States Department of Commerce’s announcement of a Preliminary Memorandum of Terms for an award under the CHIPS and Science Act to support the expansion of Samsung Electronics’ presence in Texas and the company’s development and production of leading-edge chips.