1：Experimental Design and Method Selection:

The study involved preparing a particle-free reactive silver ink composed of silver-isopropanolamine complex, formic acid, and hydroxyethyl cellulose adhesive agent. The ink was characterized for stability, and flexible electrodes were fabricated via mask-printing and thermal sintering on polyimide substrates. Effects of sintering parameters and adhesive agent content on electrical and mechanical properties were investigated.

2：Sample Selection and Data Sources:

Polyimide substrates (0.1 mm thick) from Toray Industries, Inc. were used. All reagents were analytical grade, and deionized water was used throughout.

3：1 mm thick) from Toray Industries, Inc. were used. All reagents were analytical grade, and deionized water was used throughout. List of Experimental Equipment and Materials:

3. List of Experimental Equipment and Materials: Materials included silver acetate, formic acid, isopropanolamine, hydroxyethyl cellulose, ethanol, isopropanol, and polyimide substrates. Equipment included UV–vis spectrophotometer, FT-IR spectrophotometer, XRD, XPS, TG apparatus, TEM, SEM with EDS, four-point probe, surface profiler, digital milliohmmeter, and constant temperature box.

4：Experimental Procedures and Operational Workflow:

The ink was prepared by mixing IPA, deionized water, and formic acid at 3°C, dissolving silver acetate, filtering, adding HEC, and storing at -5°C. PI substrates were cleaned and dried. Ink was patterned via mask-printing (50 μm mask thickness) and sintered at temperatures from 70 to 130°C for 1 to 8 hours. Characterization included UV–vis, FT-IR, XRD, XPS, TG, TEM, SEM, electrical resistivity measurements, and flexibility tests (bending, twisting, folding).

5：Data Analysis Methods:

Electrical resistivity was calculated from sheet resistivity and thickness measurements. Microstructure porosity was calculated using Matlab software. Statistical analysis of resistance changes after mechanical tests was performed.