Fig. 2

a Electrical conductivity of PVA-CNT composites as a function of CNT concentration. b SEM image of a double-clamped piezoresistive polymer resonator made by the process illustrated in Figure 1, H = 115 µm, h = 20 µm. c Vibration amplitude and phase of the first, second, and third flexural out-of-plane modes of resonance measured optically. d Zoom on the magnitude of displacement and phase of the first flexural out-of-plane resonant frequency measured optically. Inset: snapshot of the mode shape of the first resonance mode measured optically