a–f, The responses of the sodium (a), potassium (b), glucose (c), lactate (d), temperature (e) sensors and of the FPCB (f) after 0, 30 and 60 cycles of bending. g–l, The responses of the sodium (g), potassium (h), glucose (i), lactate (j),and temperature (k) sensors and of the FPCB (l) during bending. The radii of curvature for the bending study of sensors and the FPCB were 1.5 cm and 3 cm, respectively. Data recording was paused for 30 s to change the conditions and settings.