Table 1.

Strain-induced blue→red chromatic transition of silk–PDA composite materials as a function of protein molecular weight

Silk fibroin molecular weight, kDa	Strain-induced blue→red chromatic transition, %
350–230	5.68 ± 0.32
310–150	6.24 ± 0.77
220–95	7.59 ± 0.45
130–75	8.56 ± 0.82