A tunable palladium nanoparticle film-based strain sensor in a Mott variable-range hopping regime

Abstract

 Palladium nanoparticle film-based strain sensor was fabricated by controllable deposition of nanoclusters onto flexible polymeric sheet in gas phase.  Mott variable-range hopping (VRH) transport was found to be dominant in our devices.  The gauge factor (sensitivity), which may be up to one order of magnitude greater than traditional semiconductor gauges, can be tuned by adjusting the inter-particle distance in metal nanoparticle films.  The sensor exhibits good repeatability and reliability of their electrical responses to strains.

Thin Film Protected Flexible Nanoparticle Strain Sensors: Experiments and Modeling

“…Figure 5 shows the relative resistance change of sputtered NPs on flexible substrates reported by different groups [ 35 , 36 ], underlying that Equation (3) is not able to describe their behaviour. The relative resistance change displays strain ranges that can be described with a linear Equation (4) and others where they are still linear but with a different slope ( Figure 6 ) and, hence, different sensitivity.…”

“… Relative resistance change over strain for different strain sensors based on sputtering deposited NPs. Zheng et al [ 35 ] Cr NPs-based sensor, Xie et al [ 36 ] Pd NPs -based sensor and this paper with Pt NPs. The solid-colour lines are the fitting of Equations (4) and (9) in the case of strain sensing devices, exhibiting two distinctive linear regions and the fitting of Equations (4), (9) and (12) for strain sensors with 3 different linear regions.…”

“…Relative resistance change over strain for different strain sensors based on sputtering deposited NPs. Zheng et al[35] Cr NPs -based sensor, Xie et al[36] Pd NPs -based sensor and this paper with Pt NPs. The colour lines are the fitting of Equation (4).…”

“…The model is compared not only with our data, but also with other results reported in the literature. Xie et al [ 36 ] manufactured Pd NPs-based strain sensors, using the sputtering technique and found that the g-factor is not a constant, but changes over the applied strain range. Lee et al [ 37 ] also reported non-linear behaviour of their sensor based on silver NPs.…”

“…Lee et al [ 37 ] also reported non-linear behaviour of their sensor based on silver NPs. Up to now, most attempts to model the behaviour of strain sensing devices made by either solvent-free or colloidal NPs are based on the physical model proposed by Herman et al [ 28 ], by directly applying it to the experimental data set or by applying minor modifications [ 36 ]. This approach however does not take into account key aspects of straining flexible devices that employ solvent-free NPs.…”