Mechanical stress versus strain curves of passive gels whose initial structures were prepared through thermal (black) or active aggregation based on the amplitude of the internal torque, as indicated by the colour of the curve: 1 k B T (purple) and 3 k B T (blue). All simulations were performed with initial structures prepared at Φ = 0.31. The extensile response (positive strain) is markedly different for gels obtained via thermal or active aggregation. The gels assembled in the thermal bath responded linearly and symmetrically, behaving as an elastic solid in the range shown. The gels produced through active aggregation were highly nonlinear, elastic in compression and stiff under extension. Compression and extension curves are plotted independently (see Supplementary Information for the deformation protocol). Each data symbol is the average of 24 measurements and the error bars show the standard deviation ( Supplementary Information ).
