Fig. 2: Characterization of the wireless electrical nanopatches.

a AFM image of graphene nanosheets and the corresponding size statistics. b Raman spectra of graphene nanosheets. c COMSOL simulation showing the generated electrical field on a graphene nanosheet under a rotating magnetic field. d Analysis of the induced electrical signals of a graphene nanosheet under the magnetic field at different stages in a representative cycle. e Voltage generated on the graphene film made of graphene nanosheets when placed under a rotating magnetic field at rotation speeds of 600 rpm. f Fluorescence images of NSCs after being wrapped with graphene nanosheets for 3 h and cultured for two days. The graphene nanosheets were labeled with a dye to give red fluorescence. The cell membrane was pre-stained with PKH67 into green. The nuclei were stained into blue by Hoechst. g SEM image of NSCs after being individually wrapped with graphene nanosheets. h Viability of NSCs after being wrapped with graphene nanosheets at concentrations of 0, 30, 60, and 90 μg mL⁻¹ for 1, 2 and 3 days. Data represent three independent experiments and are presented as the mean ± standard deviation, as analyzed by a one-way ANOVA, with Tukey’s multiple comparisons test (nsp>0.05 compared to the 0 μg mL⁻¹ group). i Proliferation of nanopatch-wrapped and unwrapped NSCs in the absence or present of a 600-rpm magnetic field for 1, 2, and 3 days. Data represent three independent experiments and are presented as the mean ± standard deviation, as analyzed by a one-way ANOVA, with Tukey’s multiple comparisons test (nsp>0.05 compared to the Ctrl group).