The Young's modulus for the Mylar (biaxially-oriented polyethylene terephthalate) and cellulose acetate ribbons used in the experiments were obtained using a commercial Instron Universal Testing Instrument. In this test, the stress-strain relation is measured while the ribbon is clamped at its ends and stretched longitudinally with a prescribed velocity using a servo motor, while the tensile force is recorded using strain gauges. To obtain the mechanical response of Mylar, we performed tensile

more »

... ests using ribbons with width W = 7.0 ± 0.3mm, length L 0 = 50.0 ± 0.3mm, and thickness t = 254±3μm. The tension was increased with a speed 15μm/s. For cellulose acetate, we performed tensile tests using ribbons with width W = 20.0 ± 0.3mm, length L 0 = 70.0 ± 0.3mm, and thickness t = 254±3μm. The tension was increased with a speed 1mm/s in this case. Figure S1: Stress-strain curves for (a) Mylar and (b) Cellulose acetate. (a) Loading curves of ribbon composed of Mylar showing a linear response for strains smaller than 2% and characterized by a Young's modulus E = 3.4GPa obtained by a linear fit (black dashed line). At larger strain, nonlinear response and plastic behavior are observed. (b) Loading curves of ribbon made of cellulose acetate showing a linear response for strain smaller than 2% and characterized by a Young's modulus E = 2.2GPa obtained by a linear fit (black dashed line). At larger strain, nonlinear response is observed rapidly followed by a complete rupture of the sample. In Figure S1 , we plot the stress-strain response of the ribbon of both materials. Here the stress is calculated as the tensile force F divided by the cross section area Wt and the strain is calculated using Electronic Supplementary Material (ESI) for Soft Matter. This journal is