mbnu FY2021 Annual Report 3.1.1

Fig. 1: Evolution of retardation fields with increasing Wi (i.e., flow rate) for a viscoelastic wormlike micellar solution in the ordered staggered post array and in aligned arrays with increasing disorder β: (A) normalized, time-averaged retardation fields δ/max(δ) and (B) local retardation fluctuations rms. Flow is from left to right and the field of view is centered at the coordinate origin at the center of each array (54% of full field of view shown). (Scale bar: 250 μm). For an initially aligned array, it is seen that introducing disorder tends to enhance the chaotic fluctuations. This contrasts with the results of Walkama et al. for introducing disorder to a staggered array.