A novel fluidic strain sensor for large strain measurement

A Soft Strain Sensor Based on Ionic and Metal Liquids

“…As previously demonstrated [23], the resistivity of the saline solution is much greater than that of eGaIn. Indeed, the conduction mechanism of saline solution is fundamentally different from that of eGaIn, since it is the movement of hydrated ions that makes a saline solution electrically conductive.…”

“…Cheung et al have proposed a cylindrical strain sensor using a saline solution and reported the analysis of the impedance of the solutions over a very wide range of frequency and strain [23]. However, the sensor was considerably larger than in the present study and involved the use of rigid metal electrodes.…”

“…Hence, the final NiNs and NiCCF proportion used in our interfaces was chosen as a trade-off between the two above undesired effects: the chosen mixture contained 4% NiNs and 0.09% (length 800 μm) NiCCF by volume. The measured resistivity was 80 /cm, which was much greater than eGaIn, but negligible compared to that of the ionic solution [23]. The interaction between the two different particle types is apparent in the scanning electron microscopy image shown in Figure 5.…”

“…At the other extreme, an extremely high frequency will increase the conductivity of the solution by the Debye-Falkenhagen effect [39]. As previously shown, at frequencies between 40 Hz and 10 MHz, the real part of the impedance will slowly decrease in a predictable way [23]. The dependence of the resistance of the ionic solution on frequency will have an impact on eq.…”

“…Previous characterization of the dependence of the impedance of the ionic solution on frequency [23], [38] shows that the frequency of the AC signal can be a major influence on the flow of ions and thus on the real part of the impedance. Direct current (or an extremely low frequency) will cause electrolysis and polarize the electrodes.…”