“…Thus, the selection of optimal materials satisfying these requirements needs to be the priority before the fabrication of microfluidic devices, including polymers [14,102,117,128], metals [135], glass [105,114,136], silicon [114,136], and ceramics [137]. Among which, polymers, including PDMS [102,126,[138][139][140][141], PMMA [14,128,[142][143][144][145], epoxy resins [15], hydrogels [110,146,147], etc [19], are increasingly used for microfluidic devices because of their merits of low cost and outstanding formability [126]. PDMS is one of the most widely used materials for microfluidic devices [126] with the merits of high elasticity, low viscosity variation with temperature, water resistance, 10 µm [41,122,132] Photosensitive resin [41], Negative Hydrogel [133] Two-photon polymerization (TPP) 50 nm [119,123] Photoresist [123], Negative Sol-gel [119] small surface tension, weather resistance, high shear resistance, low cost, well-operated mold, excellent clarity, natural hydrophobicity, biological compatibility [111], and electrical insulation…”