## 3 Conclusions and Perspective
\begin{table}
\begin{tabular}{c c c c} \hline
**Filler** & **Polymer Backbone** & **Proton Conductivity (S cm\({}^{-1}\))** & **Conditions** \\ \hline MOF-bpy [125] & Nafion & \(2.6\times 10^{-2}\) & Ambient conditions \\ \hline MOF-bpe [125] & Nafion & \(2.95\times 10^{-1}\) & Ambient conditions \\ \hline ZTF-67 NFMs [126] & Nafion & \(2.88\times 10^{-1}\) & 80 \({}^{\circ}\)C, 100\% RH \\ \hline ZHNFs [127] & Nafion & \(2.77\times 10^{-1}\) & 80 \({}^{\circ}\)C, 100\% RH \\ \hline MOF-Mn1 [128] & Nafion & \(3.35\times 10^{-4}\) & 70 \({}^{\circ}\)C, 30\% RH \\ \hline MOF-Mn2 [128] & Nafion & \(3.67\times 10^{-4}\) & 70 \({}^{\circ}\)C, 30\% RH \\ \hline H\({}_{3}\)PO\({}_{4}\)/Ni-BDC [129] & PAN & \(1.05\times 10^{-2}\) & 80 \({}^{\circ}\)C, 90\% RH \\ \hline Ni-BDC [129] & PAN & \(1.67\times 10^{-4}\) & 80 \({}^{\circ}\)C, 90\% RH \\ \hline
[BMIM]BF4@Uio-67) [130] & PAN & \(2.53\times 10^{-4}\) & 90 \({}^{\circ}\)C, 35\% RH \\ \hline Ni-BDC [131] & PAN & \(6.04\times 10^{-5}\) & 90 \({}^{\circ}\)C, 90\% RH \\ \hline Zr-Cr-SO\({}_{3}\)H [132] & BSP & \(1.54\times 10^{-1}\) & 80 \({}^{\circ}\)C, 100\% RH \\ \hline MOF-Z4 [133] & PVA & \(2.1\times 10^{-4}\) & 65 \({}^{\circ}\)C, 98\% RH \\ \hline MOF-Z5 [133] & PVA & \(2.9\times 10^{-4}\) & 65 \({}^{\circ}\)C, 98\% RH \\ \hline ZTF-8 [134] & PBI & \(3.1\times 10^{-3}\) & 200 \({}^{\circ}\)C, anhydrous \\ \hline ZIF-67 [134] & PBI & \(4.1\times 10^{-2}\) & 200 \({}^{\circ}\)C, anhydrous \\ \hline ZIF-8 + ZIF-67 [134] & PBI & \(9.1\times 10^{-2}\) & 200 \({}^{\circ}\)C, anhydrous \\ \hline MIL-100(Fe) [135] & sPSU & \(2.55\times 10^{-3}\) & 25 \({}^{\circ}\)C, 100\% RH \\ \hline UiO-66-NH\({}_{2}\)-Glu [136] & sPSU & \(2.1\times 10^{-1}\) & 80 \({}^{\circ}\)C, 100\% RH \\ \hline \end{tabular}  
* SPES—sulfonated polyethersulfone; SPEEK—sulfonated poly(ether ether ketone); PBI—polybenzimidazole; SPS–sulfonated polysulfone; SPAEK—sulfonated poly(arylene ether ketone); SPPO—sulfonated poly(phenylene oxide); PAN—polyacrylonitrile; BSP, PBA—poly(butyl acrylate); sPSU—sulfonated polysulfone; BSP—branched sulfonated polymer.  
\end{table} 
Table 2: _Cont._Improvements in certainty will require more powerful and accurate practical models, and artificial-intelligence-based methods will be in demand [137; 138; 139; 140; 141; 142]. Conceptualization, A.K., V.K., P.P. and S.S.; investigation, A.K. ; resources, A.K. and P.P. ; data curation, A.K. ; writing--original draft preparation, A.K. ; writing--review and editing, A.K., V.K., S.S. and P.P. ; visualization, A.K. and S.S.; supervision, V.K. and S.S.; project administration, V.K. and S.S.; funding acquisition V.K., S.S. and P.P. All authors have read and agreed to the published version of the manuscript. This work acknowledges support from Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Science, ICT & Future Planning (No. 2022R1A2C1006090, 2017R1A2B4008801), NRF Basic Research Programme in Science and Engineering by the Ministry of Education (No. 2017R1D1A1B03036226). V.K. also thankfully acknowledges the support from the National Convergence Research of Scientific Challenges through the National Research Foundation of Korea (NRF) funded by Ministry of Science and ICT (No. 2021 MSF7A1017476) and by the INDO-KOREA JNC program of the National Research Foundation of Korea Grant No. 2017K1A3A1A68. Not Applicable. The authors declare no conflict of interest. References