This Flexible Pressure Sensor Really Keeps Its Cool, Even When Operating in Lava Eruptions
Capable of withstanding the temperatures you'd find in an erupting volcano, this flexible pressure sensor can go where others fear to tread.
Researchers from the University of Houston and King Abdullah University of Science and Technology (KAUST) have developed piezoelectric sensors which can flex under pressure and operate in extreme environments — including in temperatures associated with volcanic eruptions.
The team, led by corresponding author Jae-Hyun Ryou, associate professor of mechanical engineering, was looking for ways to build sensors which could survive where standard electronics would fail — high-pressure petrochemical pipelines from geothermal wells where the temperature reaches over 1,100°F and mafic volcanic lava eruptions which get as hot as 1,650°F. "Highly sensitive, reliable and durable sensors that can tolerate such extreme environments are necessary for the efficiency, maintenance, and integrity of these applications," Ryou explains.
The team's work builds on earlier efforts to turn single-crystal gallium nitride films into piezoelectric pressure sensors — the results of which outperformed rival devices but began to lose sensitivity when heated above 660°F. Deciding the design needed a wider bandgap — the minimum energy needed to excite an electron and thus conduct electricity — the team switched to aluminum nitride films instead, and discovered a major improvement in maximum operating temperature.
"Our plan is to use the sensor in several harsh scenarios," Ryou says of the group's real-world testing plans, following lab experiments which included running the sensor inside a high-temperature furnace. "For example, in nuclear plants for neutron exposure and hydrogen storage to test under high pressure. AlN sensors can operate in neutron-exposed atmospheres and at very high-pressure ranges thanks to its stable material properties."
The researchers are also looking at other uses for the sensor technology, including using its flexibility in wearable health monitoring systems and soft robotics — but there's no word yet on a timeline for commercialization. "It's hard to put a specific date on when that might be," says first author Nam-In Kim, "but I think it's our job as engineers to make it happen as soon as possible."
The team's work has been published under closed-access terms in the journal Advanced Functional Materials.