In a study published in Science, a team at the University of Southern California unveiled a new type of memory device that continues to operate at 700 degrees Celsius (~1300 degrees Fahrenheit). That temperature exceeds molten lava and goes far beyond anything previously achieved for this class of technology. The device showed no sign of failure. In fact, 700 degrees was simply the maximum their equipment could test.
“You may call it a revolution,” said Joshua Yang, team lead and Arthur B. Freeman chair professor at the Ming Hsieh Department of Electrical and Computer Engineering at the USC Viterbi School of Engineering and the USC School of Advanced Computing. “It is the best high-temperature memory ever demonstrated.”
The new device is known as a memristor, a nanoscale component that can both store data and perform computations. It is constructed like a microscopic layered structure, with two electrodes on either side and a thin ceramic layer in between.
Jian Zhao, the study’s first author, built the device using tungsten for the top electrode, hafnium oxide ceramic in the middle, and graphene for the bottom layer. Tungsten has the highest melting point of any element, while graphene, a single-atom-thick sheet of carbon, is known for its exceptional strength and heat resistance.
This combination produced remarkable performance. The device retained data for more than 50 hours at 700 degrees without needing to be refreshed. It also endured over one billion switching cycles at that temperature and operated at just 1.5 volts with speeds measured in tens of nanoseconds.
Further investigation revealed why the device performed so well. In conventional electronics, heat causes metal atoms in the top electrode to slowly migrate through the ceramic layer. Eventually, they reach the bottom electrode, creating a permanent connection that short-circuits the device and leaves it stuck in the on state.
Graphene prevents this failure. Its interaction with tungsten is, as Yang described it, similar to oil and water. Tungsten atoms that approach the graphene surface cannot attach to it. Without a stable point to settle, they drift away instead of forming a conductive bridge. This prevents short circuits and preserves the device’s function even under extreme heat.
The researchers confirmed this mechanism using advanced electron microscopy, spectroscopy, and quantum-level simulations. By understanding what happens at the atomic interface, they have turned an unexpected result into a principle that could guide future designs. Other materials with similar surface properties could be identified, which may help scale the technology for industrial production.
Electronics capable of operating above 500 degrees Celsius have long been a goal for space exploration. Venus, for example, has a surface temperature around that level, and every lander sent there has failed in part due to extreme heat. Current silicon-based chips cannot survive such conditions.
“We are now above 700 degrees, and we suspect it will go higher,” Yang said.
The potential applications go far beyond space missions. Geothermal energy systems require electronics that can function deep underground, where surrounding rock can glow red-hot. Nuclear and fusion systems also expose equipment to intense heat. Even in everyday settings, durability improves significantly. A device rated for 700 degrees would be extremely robust at the roughly 125-degree temperatures often reached inside automotive electronics.
In addition to storing data, the device offers a major advantage for artificial intelligence. Many AI systems rely heavily on matrix multiplication, a mathematical operation used in tasks like image recognition and language processing. Traditional computers perform these calculations step by step, consuming large amounts of energy.
Memristors approach the problem differently. By using Ohm’s Law, where voltage times conductance equals current, the device performs calculations directly as electricity flows through it. The result is obtained instantly as the measured current.
“Over 92 percent of the computing in AI systems like ChatGPT is nothing but matrix multiplication,” Yang said. “This type of device can perform that in the most efficient way, orders of magnitude faster and at lower energy.”
Despite the promising results, Yang emphasizes that practical applications are still some distance away. Memory is only one part of a complete computing system. High-temperature logic circuits will also need to be developed and integrated. In addition, the current devices were built manually at very small scales in a laboratory setting, so manufacturing at scale will take time.
“This is the first step,” Yang said. “It’s still a long way to go. But logically, you can see: now it makes it possible. The missing component has been made.”
Image – A newly developed memory device can survive extreme heat—up to 700°C—without breaking down, overcoming a major barrier in electronics. Even more striking, it could dramatically speed up AI computations while using far less energy. Courtesy of: AI/ScienceDaily.com.
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