Wireless Passive Sensor Technology through Electrically Conductive Media over an Acoustic Channel

Area of Science:

• Materials Science and Engineering
• Sensor Technology
• Mechanical Engineering

Background:

• Hydrogen storage in carbon-fiber-reinforced polymer (CFRP) tanks is crucial for climate-friendly mobility.
• Internal monitoring of these high-pressure tanks is essential for safety and long-term operation.
• Existing wired and wireless technologies are unsuitable for internal tank monitoring due to the harsh environment.

Purpose of the Study:

• To present a novel passive wireless sensor technology for internal monitoring of CFRP hydrogen tanks.
• To demonstrate acoustic communication through the tank hull using ultrasonic waves.
• To enable wireless temperature measurement within the operational range of hydrogen tanks.

Main Methods:

• Development of a passive wireless sensor node utilizing an analog resonant sensor with a high quality factor.
• Implementation of an ultrasonic communication channel through the electrically conductive CFRP tank hull.
• Characterization of electric impedances and acoustic transmission for designing the measurement setup.

Main Results:

• Successful wireless temperature measurement through a 10 mm CFRP plate.
• Demonstrated operation across the full temperature range of -40 to 110 °C.
• Achieved a high-resolution temperature measurement with less than 1 mK accuracy.

Conclusions:

• The developed passive wireless sensor technology is effective for monitoring CFRP hydrogen tanks.
• Ultrasonic acoustic communication provides a viable method for internal tank sensing.
• This technology enhances the safety and reliability of hydrogen-based mobility solutions.