A Flexible Piezoelectric Strain Sensor Array With Laser-Patterned Serpentine Interconnects

In consideration of its high electromechanical coupling coefficient, thinned piezoelectric thick film from the bulk materials by chemical and mechanical polishing (CMP) process is used for high-performance piezoelectric harvesters and flexible sensors. Here, the flexible strain sensor 3 × 3 array based on CMP fabrication method is presented for the first time, and the laser-patterned flexible stainless steel serpentine wires as interconnects signal. The testing results show that the output voltages of the strain sensor array exhibit good linearity towards the corresponding strains, and also increase with the applied frequency. The maximum sensitivity of strain sensor array is 1.88 mV/με. Moreover, this sensor array is demonstrated to monitor the surface strain of a complex structure such as the contraction and expansion of irregular balloon, which indicates its great promising in monitoring vital signs for heart healthcare.