Fig. 1. Schematic diagram of microfiber fabrication

Fig. 2. Schematic diagram of the process of coated PVA

Fig. 3. U-shaped sensor structure illustration

Fig. 4. U-shaped sensor electron microscope diagram

Fig. 5. Transmittance spectrum of the sensor at 34% RH

Fig. 6. Sensor humidity experimental equipment diagram

Fig. 7. Spectrogram of resonant peak wavelength at 1 420~1 475 with humidity for sensor S-1 with a fit at 1 450~1 480 nm

Fig. 8. Spectrogram of resonant peak wavelength at 1 430~1 488 with humidity for sensor S-2 with a fit at 1 464~1 488 nm

Fig. 9. Spectral diagram of the resonant peak wavelength of sensor S-3 at 1 410~1 470 nm as a function of humidity

Fig. 10. Fitting diagram of resonant peak wavelength variation with humidity of sensor S-3 at 1 440~1 470 nm

Fig. 11. Spectrogram of resonant peak wavelength at 1 411~1 485 nm with humidity for sensor S-4 with a fit at 1 462~1 485 nm

Fig. 12. Diagram of sensor S-2 humidity stability

Fig. 13. Spectral diagram and fitting of resonant peak wavelength variation with temperature of sensor S-1 at 1 450~1 480 nm