A Pressure Sensor Based on a Polymer Optical Waveguide With Three Cascaded Microring Resonators

Traditional electrical pressure sensors are prone to electromagnetic interference; however, the emergence of optical pressure sensors offers a novel means of fabricating flexible devices. A pressure sensor based on a polymer optical waveguide is presented in this article that incorporates three cascaded microring resonators (MRRs) for enhanced sensitivity and accuracy. The sensor was fabricated from a polymer with a low Young’s modulus to achieve flexibility and enhanced sensitivity. The wavelength change in the output spectrum of the sensor was utilized to precisely measure the pressure applied to the device, and the structural parameters and the cascaded array of MRRs were optimized to improve the sensitivity of the pressure sensor. The experimental results show that the sensor has a sensitivity of 21.86 pm/kPa within the pressure range of 0–20 kPa with an accuracy of 1 kPa. The proposed MRR array pressure sensor exhibits high sensitivity and excellent linearity and can be easily integrated into a device, indicating considerable application potential for wearable optical sensing.