. 2019 Nov 27;19(23):5196. doi: 10.3390/s19235196

Table 2.

Performance comparison of MKR-based relative humidity sensors with different sensitive materials and the physical parameters of MKRs.

Authors/Publication Year	MKR Material	Waist Diameter of Microfiber	Knot Diameter of MKR	Humidity-Sensitive Material	Sensitivity		Resolution (*RH: Relative Humidity)	Response Time
Authors/Publication Year	MKR Material	Waist Diameter of Microfiber	Knot Diameter of MKR	Humidity-Sensitive Material	Wavelength	Transmission Power	Resolution (*RH: Relative Humidity)	Response Time
Y. Wu et al./2011 [34]	Silica MKR	1.2 μm	500 μm	Not Available	~12 pm/10% RH	Not Available	0.017% RH	Not Available
Y. Wu et al./2011 [34]	Polymer MKR	2.1 μm	500 μm	Not Available	~88 pm/10% RH	Not Available	0.0023% RH	~0.5 s
K. Xu et al./2019 [35]	Silica MKR at 2-mm Waveband	1 μm	395 μm	Not Available	~10 pm/% RH	0.034 dB/% RH	Not Available	Rising: ~0.8 s Falling: ~1.55 s
M. Gouveia/2014 [36]	Silica MKR	3 μm	250 μm	Nafion	0.11 nm/% RH for low RH 0.29 nm/% RH for High RH	Not Available	Not Available	Not Available
S. Azzuhria et al./2018 [42]	Silica MKR	Not Available	3.02 μm	Graphene Oxide	0.0104 nm/% RH (0.0095 nm/% w/o Graphene Oxide)	Not Available	0.096 % RH (0.1% RH w/o graphene oxide)	Not Available
A. D. D. Le et al./2018 [29]	Silica MKR	4 μm	380 μm	Polyvinyl Alcohol (PVA)	-1.53 nm/% RH	Not Available	Not Available	Not Available
M. Faruki et al./2016 [55]	Silica MKR	2.1 μm	2.5 mm	Titanium Dioxide (TiO₂)	2.5 pm/% RH (1.3 pm/%RH w/o TiO₂)	0.0836 dB/% RH (0.0626 dB/%RH w/o TiO₂)	Not Available	Response: ~25 s Recovery: ~30 s