Flexible and Highly Sensitive Strain Sensor Array with Controlled Metal Cracks for Detecting Strain Distribution on Equipment Surfaces

With the improvement of the intelligence of mechanical equipment, it is essential to grasp the operation state of equipment to ensure its safety. The detection of strain distribution of the structural parts is an important method for strength verification of these equipment. The traditional strain gauge, can only detect a single point, can not reflect the overall strain distribution state of the structural surface, and it is not suitable for relatively small space and difficult to fit irregular curved surface. This paper proposes a flexible strain sensor array with controlled metal cracks that can accurately detect the strain distribution on the surface of the structural parts. In the flexible strain sensor designed by us, a triangular array structure is localized at the sensitive unit to realize the controlled manufacturing of micro-cracks. The consistency of the sensor unit is ensured through the lithograph-sputteringstripping process, enabling the successful fabrication of the sensor array. Upon testing, our sensor demonstrates the capability to detect micro-strains as low as 33 (0.0033%), with a gauge factor (GF) reaching 220 at very small strain levels. The proposed sensor array not only has high sensitivity, but also can solve the problem of insufficient detection points of traditional strain gauges, and can accurately reflect the strain distribution state of the structure surface. These characteristics make it have potential applications in equipment surface strain detection.