Fraunhofer to develop sensors that can withstand downhole geothermal conditions
Fraunhoffer-Gesselschaft #WeKnowHow video screenshot (source: Fraunhofer website)
Carlo Cariaga
7 Dec 2021
Project "eHarsh" aims to develop sensors that can potentially be used in the extreme pressure and temperature conditions of geothermal systems
Eight institutes of Fraunhofer – Gesselschaft are working on a project that aims to develop sensor systems that can withstand extremely high temperatures and pressures. A potential application of these sensors is in the wellbores and pumps of geothermal systems.
The project, called “eHarsh,” addresses the problem of conventional sensors getting damaged in environments that are classified as extremely harsh. These include extreme pressure and temperature, as well as exposure to aggressive gases and liquids, and dust.
“We have a lot of in-depth knowledge within the individual institutes,” says eHarsh Coordinator Holger Kappert from the Fraunhofer Institute for Microelectronic Circuits and Systems IMS. “We know a lot about heat-resistant ceramics and we have the ability to test material properties and produce robust microelectronic circuits. On our own, though, none of us were capable of creating this type of sensor. It was only through cooperation and the combination of many individual technologies that we were able to succeed.”
The aim of the project is to include the electrical components for signal processing into the robust sensors. Having the signal processing happen in the sensors themselves helps in producing high-quality sensor signals. “It also means we can network the sensors better in the future, saving on cabling effort.” added Kappert.
The sensor casing developed for the project can withstand temperatures of up to 500 degrees Celsius. The internal electrical components can withstand around 300 degrees Celsius and pressures of up to 200 bar. Some of the materials used for the sensor were a heat-resistant ceramic circuit board and conductors with a tungsten admixture A challenge that the team encountered was to how to keep the internal components intact even if the sensors go through repeated heating and cooling cycles.
“Overall, the interdisciplinary nature of ‘eHarsh’ has allowed us to successfully develop a technology platform for robust sensor systems for many different uses,” summarizes Kappert.
Source: Fraunhofer
