Fig. 2.

Structural characterization of the sensing materials and electrode. a SEM image of the accordion-microstructured MXene. The scale bar is 500 nm. b Tyndall effect of the Ti₃C₂T_x nanosheets solution. c TEM image of the Ti₃C₂T_x nanosheets. The scale bar is 100 nm. d Laser pattern of a Chinese dragon. e SEM image and its corresponding large view of the Ti₃C₂T_x nanosheets coated n-WF. The scale bar is 40 µm and 500 nm, respectively. f Bending deformation of the Ti₃C₂T_x electrode and its corresponding resistance change. Inset is the optical image of the Ti₃C₂T_x -coated n-WF. g Iontronic film on a bending PET film. h Mechanical performance of the PVA-KOH film. Inset is corresponding cross-sectional view of the PVA-KOH film. The scale bar is 10 µm