(A) Quantification of the storage modulus (G’), and (B) tan(δ) of the scaffolds with varying amounts of total carbon (graphene flakes and carbon nanotubes) using nanoindentation analysis (N=6 independent gels, n>5 measurements per gel). Gels with 1% (blue) and 2% (red) w/v alginate content are compared. Mean and standard error are shown for each graph. (C) Quantification of the bulk G’ versus % strain, with varying amounts of carbon (%) and with either 1% or 2% w/v alginate. N=4 independent gels for each composition. Legend (right) denotes the alginate w/v % of the composite, and the total amount of additive in the scaffold (%). (D) Quantification of gel conductivity with varying amounts of carbon, for 1% (blue) and 2% (red) w/v alginate. N=5 independent gels for each composition, with n>12 measurements per gel. Mean and s.d. are shown for each graph.