Fig. 3

a Schematic observation of accumulated energy on the polymer film and puncture force using a force analyzer. Actual analysis was conducted using 5 × 5 DMN FTA array. b Representative image of accumulated energy on the CMC film by the pressure of micropillars (350 µm diameter) until the film puncture point at different CMC film concentrations. c Applied force at film puncture of 350 µm diameter micropillar according to the film’s polymer solution concentration. (n = 5, mean ± S.E.). d Image showing 300 µm, 350 µm, and 400 µm diameter micropillars used in the experiment (Scale bar = 500 µm). e Measured film puncture force of 2%, 4%, and 6% CMC film following the micropillars’ diameter (300 µm, 350 µm, and 400 µm) (n = 5, mean ± S.E.). Statistical significance was set at p < 0.05; ^*p < 0.05, ^**p < 0.01, ^***p < 0.001