Silicon nanostructure-based photonic MEMS sensor for biosensing application

• Published in: Journal of nanophotonics 2021-04, Vol.15 (2), p.026001-026001
• Main Authors: Upadhyaya, Anup M, Srivastava, Maneesh C, Sharan, Preeta, Roy, Sandip Kumar
• Format: Article
• Language: English
• ISSN: 1934-2608; 1934-2608
• DOI: 10.1117/1.JNP.15.026001

We explored the design of an optical pressure sensor. The objective is to create a photonic microelectromechanical system-based cantilever sensor design to detect prostate-specific antigen, a protein biomarker associated with prostate cancer. Sensor’s performance for the early detection of cancerous cells is dependent on sensitivity. The designed sensor consists of a hexagonal ring integrated with microcantilevers. Two types of microcantilever such as rectangular profile and V profile with integrated photonic sensing layer are investigated for sensitivity, quality factor, and resonant wavelength. The analysis shows that a geometrical modification of microcantilever has a significant effect on sensitivity enhancement. The finite difference time domain tool is used for designing photonic ring resonator patches. Numerical analysis of microcantilever is considered to investigate surface stress behavior. The cantilever deformation due to applied pressure resulted in a change in the index of refraction. Results show that the sensitivity of 55  nm  /  MPa for a triangular-shaped microcantilever obtained is higher compared to the rectangular-shaped microcantilever with a sensitivity of 0.19  nm  /  MPa. The designed structures have significantly higher sensitivities than the previously published sensitivity of 3.27  nm  /  MPa at wavelength 1550 nm. The maximum quality factor obtained for the rectangular shape is 2852 and 77,510 for the triangular shape. Triangular-shaped microcantilever can minimize winding inflexibility or stiffness. This capability of the triangular-shaped microcantilever enhances feasibility in making the final packaging and future fabrication.