5G-enabled, battery-less smart skins for self-monitoring megastructures and digital twin applications

Area of Science:

• Electrical Engineering
• Materials Science
• Structural Health Monitoring

Background:

• The advancement of 5G infrastructure creates opportunities for deploying battery-less sensors.
• Fully-passive devices offer enhanced detectability for self-monitoring megastructures.
• Existing battery-less solutions have limitations in detectability and monitoring scope.

Purpose of the Study:

• To develop and demonstrate a battery-less mmWave reflect-array sensor for local strain monitoring.
• To enable ubiquitous structural health monitoring of composite materials using passive sensors.
• To explore the potential of these sensors for digital twinning applications in smart cities.

Main Methods:

• Utilized a Van-Atta array design for a 'smart' skin sensor.
• Developed millimeter-wave identification (mmID) tags for mounting or embedding in composite materials.
• Tested sensor prototypes on carbon fiber and glass fiber composites, measuring radar cross-section, resolution, and sensitivity.

Main Results:

• Prototypes exhibited high radar cross-sections (-33.75 dBsm mounted, -35.00 dBsm embedded).
• Achieved a minimum strain resolution of 202 µ-strain, even at 40° off-axis.
• Demonstrated repeatable and recoverable strain responses (0-3000 µ-strain) with high sensitivity.

Conclusions:

• The 5G-enabled, battery-less mmWave sensor provides a highly detectable solution for structural health monitoring.
• The 'smart' skin sensor facilitates local strain monitoring of composite materials with wide interrogation angles.
• These passive sensors hold significant potential for ubiquitous digital twinning in future smart city architectures.