Table 2. A comparison of the electrochemical effective area A _eff, calculated via the quasi-reversible Randles–Ševčík equation (see Methods section) and the geometrical surface area A _Geo, (calculated from the physical contact area immersed within 1 mM hexaammineruthenium (III) chloride/0.1 M KCl) of the graphene/PLA and printed 3DE. The real area percentage, A_Real, is also presented for additional comparison (see Methods section).

Electrode	AGeo/cm2	Aeff/cm2	AReal/%
Graphene/PLA	0.13	0.066	50.77
3DE	0.36	0.085	23.61