Fig. 1
From: Matched asymptotic solution for crease nucleation in soft solids
Crease formation in a compressed soft slab. a A 5 × 5 × 2 cm3 soft block is made by mixing 37.2 mL of deionised water containing Blue Dextran (1 mg/mL) with 16 mL of 0.5 M Tris–HCl buffer at pH 6.8, and 8.75 mL of a solution containing Acrylamide (30% w/v) and Bis-acrylamide (0.8% w/v) in a soft silicone-based mould. In total 625 μL of APS solution (10% w/v) and 125 μL TEMED were gently mixed to the gel-forming mixture, which was allowed to polymerise for 1 h. b The gel is then gently pulled out from the mould and axially compressed by hand using polystyrene sheets to avoid friction. The white arrow indicates the finite crease at the free surface observed at an axial stretch of about \(\lambda _x \simeq 0.6\)
