Flexible Sensorized Tube for Pipeline Defect Detection Based on Bending and Pressure Sensing

Area of Science:

• Materials Science and Engineering
• Sensor Technology
• Civil Infrastructure Monitoring

Background:

• Urban pipelines are critical infrastructure, but their curved and confined nature complicates sensing.
• Existing flexible sensors suffer from signal interference between pressure and bending measurements.
• A need exists for robust, multimodal sensing solutions for pipeline integrity assessment.

Purpose of the Study:

• To develop an integrated multi-array sensor for urban pipelines capable of distinguishing pressure and bending signals.
• To address the challenge of cross-interference in conventional flexible sensing devices.
• To enable reliable defect detection and spatial monitoring within complex pipeline structures.

Main Methods:

• Integration of laser-induced graphene pressure sensors and bending sensors onto a polydimethylsiloxane substrate using flexible printed circuits.
• Development of a sensing architecture based on geometry-induced strain-field differentiation.
• Testing in simulated pipeline environments to analyze signal patterns from defects like protrusions and corrosion.

Main Results:

• The integrated sensor demonstrated high linearity (R² > 0.99), low hysteresis (2.68%), and a fast response time (~50 ms) under pressure loading (0-120 kPa).
• Geometry-induced strain-field differentiation effectively suppressed pressure-bending cross-interference.
• Distinct signal patterns were observed for protrusion and corrosion defects, enabling clear identification.

Conclusions:

• The proposed sensor integration strategy provides stable and reliable multimodal signal acquisition for urban pipelines.
• The device enables accurate defect identification and spatial posture sensing in complex, curved pipeline conditions.
• This technology offers a promising solution for enhanced pipeline integrity monitoring and maintenance.