Diethylene glycol monobutyl ether

Five units of a roll‐to‐roll printing system (Figure S2, Supporting Information) were used, namely the unwinder, first gravure unit, second gravure unit, imprinting unit, and finally rewinder unit from left to right. Rolls with 270 mm width were used to print and imprint the carbon‐black thin films and PDMS‐based PCR chips. Carbon‐black ink with 1000 C_p viscosity was used, prepared by mixing the solvent of diethylene glycol mono butyl ether (Sigma Aldrich) and carbon‐black paste (Dozentech Korea) using a mechanical stirrer at room temperature for 2 h. The flexographic plate‐based mold was first designed using AutoCAD software. The designed flexographic plate was fabricated by Hyunjin Flexo in Korea.

The following metal precursors and solvents were used: Titanium (IV) isopropoxide (Sigma-Aldrich, 97%), hafnium (IV) isopropoxide isopropanol adduct (Alfa Aesar, 99%), ammonium (meta)tungstate hydrate (Sigma-Aldrich, ≥85.0%), 2-ethylhexanoic acid (2-EHA) (Sigma-Aldrich, 99%), xylene (Sigma-Aldrich, ≥98.5%), ethanol absolute (VWR chemicals, ≥99.8%), diethylene glycol monobutyl ether (Sigma-Aldrich, ≥98.0%). 50 nm Au nanospheres (Citrate, BioPure^TM) in USP purified water (1 mg/mL) were purchased from nanoComposix Inc (San Diego, USA). Hydrophilic fumed silicon dioxide nanoparticles (Aerosil^®, A380) were obtained from Evonik Industries AG (Essen, Germany).