Fig. 1

a Schematic of the fabrication process of the MWCNT/graphene hybrid sensor. All scale bars in the photographs of the sensors are 5 mm. b SEM images of MWCNT/graphene hybrids. The MWCNT and graphene are randomly distributed on the Ecoflex substrate. c Partial enlargement of b. The green dotted line is the edge of graphene and the red arrows indicate the MWCNTs that bridge the graphenes. d Raman spectra of pristine Ecoflex, MWCNT-, graphene-, and MWCNT-graphene-coated Ecoflex.