Portable Automatic Microring Resonator System Using a Subwavelength Grating Metamaterial Waveguide for High-Sensitivity Real-Time Optical-Biosensing Applications. - Varun Soni; Ching-Wen Chang; Xiaochuan Xu; Chao Wang; Hai Yan; Michael J. D'Agati; Li-Wei Tu; Quark Yungsung Chen; Huiping Tian; Ray T. Chen (IEEE Trans. Biomed. Eng., 2021)