Impedance-Domain Decoupled Single-Architecture Multimodal Strain Sensor Array for Full-Field Strain Mapping

Area of Science:

• Materials Science
• Mechanical Engineering
• Sensor Technology

Background:

• Multimodal strain sensors offer expanded sensing capabilities but often suffer from complex designs and crosstalk.
• Existing devices lack intrinsic pathways for capturing dynamic strain information, limiting their application scope.

Purpose of the Study:

• To develop a simplified multimodal sensor with intrinsically decoupled sensing pathways for dynamic and static strain.
• To enable high-fidelity structural health assessment through spatiotemporal strain mapping.

Main Methods:

• A novel sandwich-type piezoelectric architecture was designed, integrating a microcrack-based piezoresistive layer as both electrode and sensing element.
• Ultrasonic spray coating was employed for scalable fabrication of large-area sensor arrays (>10 cm × 10 cm).
• Impedance-domain separation was utilized within a shared electrical channel to decouple piezoresistive (strain magnitude) and piezoelectric (strain rate) outputs.

Main Results:

• The sensor achieved intrinsically decoupled dynamic-static strain sensing, with piezoelectric output reflecting strain rate and piezoresistive output reflecting strain magnitude.
• The piezoresistive layer demonstrated an ultrawide linear strain range (0.001%-45%) and a high dynamic response (up to 700 Hz).
• Fabricated sensor arrays exhibited uniform morphology and reliable performance, enabling spatiotemporal mapping of micron-scale deformations.

Conclusions:

• The simplified multimodal sensor architecture offers a robust framework for comprehensive structural health assessment.
• The developed technology facilitates reliable identification of failure sites under vibrational excitations.
• This approach paves the way for advanced, high-fidelity monitoring systems in various engineering applications.