Sensors operating in nuclear reactors, geothermal wells, petrochemical plants and other harsh industrial environments must be able to endure elevated temperatures. A new piezoelectric sensor designed by researchers from King Abdullah University of Science and Technology (Saudi Arabia) and the University of Houston has been demonstrated to withstand these industrial heat extremes.

The design builds on a device previously developed with single-crystalline gallium nitride (GaN), thin films for harsh-environment applications. A decline in sensor sensitivity at temperatures higher than 350° C was attributed to an insufficiently wide bandgap, leading the researchers to engineer a sensor with aluminum nitride (AIN).

This material alteration proved successful in overcoming thermal hurdles, as the AIN sensor performed effectively in temperatures as high as 900° C, reportedly the temperature at which the hottest type of lava on Earth erupts. Relative to the GaN-based sensor, the AIN-based device offers a wider bandgap and an even higher temperature range.

The sensor also features high radiation resistance and is resistant to organic solvents, seawater, ultraviolet light, and weak acids and alkalis. Its flexibility offers scope for inclusion in wearable sensors in personal health care monitoring products and for use in precise-sensing soft robotics.

The research is published in Advanced Functional Materials.