ANN ARBOR, Mich. -- Scientists have developed a groundbreaking computer memory device that can operate at temperatures over 1100°F (600°C) - hot enough to withstand the blazing conditions inside jet engines, geothermal wells, and even on the surface of Venus. This breakthrough could help overcome one of the most fundamental limitations of modern electronics: their inability to function at very high temperatures.
Contemporary electronics are built on silicon semiconductors, which start to fail at temperatures above 150°C (302°F). When heated above this temperature, these semiconductors begin conducting uncontrollable levels of current. Since electronics are precisely manufactured to operate at specific current levels, this heat-induced current can wipe information from a device's memory. This temperature limit has prevented the use of sophisticated electronics in environments like aerospace engines (150°C-600°C), Venus exploration missions (550°C), and deep geothermal wells (300°C-600°C).
A research team led by scientists from the University of Michigan, in collaboration with Sandia National Laboratory, has now shattered this thermal barrier. Their device, detailed in a recent paper published in the journal Device, operates through an electrochemical process similar to a battery, but instead of storing energy, it stores information. The system uses a solid electrolyte barrier that allows only oxygen ions to move between layers while blocking other charged particles.
"It could enable electronic devices that didn't exist for high-temperature applications before," says Yiyang Li, assistant professor of materials science and engineering at the University of Michigan and the study's senior corresponding author, in a statement.
The device's architecture consists of three main layers: a semiconductor made of tantalum oxide, a metal layer of tantalum, and a solid electrolyte called yttria-stabilized zirconia (YSZ) sandwiched between them. Three platinum electrodes control the movement of oxygen ions through this structure. Unlike the electrons in conventional memory, these oxygen ions remain stable even at extreme temperatures.
When oxygen atoms leave the tantalum oxide layer, they create a region of metallic tantalum. Simultaneously, a tantalum oxide layer forms on the opposite side of the barrier. These layers maintain their separation, much like oil and water, ensuring the stored information remains stable until deliberately changed by applying a new voltage. By controlling the oxygen content, the researchers can change how easily electrical current flows through the material, creating different states that represent stored information.
The researchers demonstrated their device's remarkable durability through rigorous testing. It could switch between different states more than 10,000 times without failing and maintained its stored information for at least 24 hours at both 400°C (752°F) and 600°C (1,112°F). Currently, the device can store one bit of information, but Li notes that "with more development and investment, it could in theory hold megabytes or gigabytes of data."
The system does have one significant limitation: new information can only be written to the device at temperatures above 250°C (500°F). However, the researchers suggest this constraint could be overcome by incorporating a heater for devices that need to operate at lower temperatures.
Beyond just storing binary information (ones and zeros), the device can maintain multiple intermediate states, making it capable of analog storage. This capability could be particularly valuable for artificial intelligence applications in extreme environments, where processing power and energy efficiency are crucial concerns.
"There's a lot of interest in using AI to improve monitoring in these extreme settings, but they require beefy processor chips that run on a lot of power, and a lot of these extreme settings also have strict power budgets," explained Alec Talin, a senior scientist at Sandia National Laboratories and study co-author. "In-memory computing chips could help process some of that data before it reaches the AI chips and reduce the device's overall power use."
While other high-temperature memory technologies exist, this new device offers distinct advantages: it operates at lower voltages than alternatives like ferroelectric memory and polycrystalline platinum electrode nanogaps, while providing more analog states for in-memory computing. The device can maintain its information states above 1100°F for more than 24 hours, matching the temperature performance of the best existing technologies while offering these additional benefits.
The researchers have already filed a patent and are seeking partners to bring the technology to market. This advancement could enable new generations of electronics capable of operating in environments that were previously off-limits to sophisticated computer systems, from the depths of geothermal wells to the surface of other planets.