Fig. 4: Electrical performance of AiFoam.
From: Artificially innervated self-healing foams as synthetic piezo-impedance sensor skins
a Nyquist plots of foam materials with different volume fractional μNi loadings. Re(Z) represents the real part of the impedance and Im(Z) represents the imaginary part of the impedance. Inset is the equivalent circuit of the foam materials, where R1 represents the bulk resistance; CPE1 and R2 represent the double-layered constant phase element (CPE) and the polarization resistance of one of the component, respectively; CPE2 and R3 represent the double-layered capacitance and the polarization resistance of the other component; W1 represents the mass transport process. CPE is used to account imperfect capacitance caused by imperfect interfaces or nonuniformity (Supplementary Fig. 17). b The real part of the dielectric permittivity of foam materials with different volume fractional μNi loadings under the frequency range of 1–105 Hz. The error bars are calculated based on three samples. c Resistance and d capacitance change responses of AiFoam with different volume fractional μNi loadings under normal pressure. R0 and C0 represent the initial resistance and capacitance of the sensor, whereas R and C represent the resistance and capacitance of the sensor during the pressing test. The data of c, d were collected simultaneously.
