Nanoparticle films as sensitive strain gauges

Abstract

We demonstrate that thin films consisting of cross-linked nanoparticle aggregates function as highly sensitive strain gauges. The sensors exploit the exponential dependence of the interparticle tunnel resistance on the particle separation. Their sensitivity (gauge factor) is two orders of magnitude higher than that of conventional metal foil gauges and rivals that of state-of-the-art semiconductor gauges. We describe the strain gauge behavior in a tunneling model that predicts the dependence of the gauge factor on several parameters, in particular, the nanoparticle size, the interparticle separation gap, and the conductance of the linker molecules.

Metallic nanoparticle-based strain sensors elaborated by atomic layer deposition

“…At a strain of 0.5%, a sensitivity DR=R e of 70 is reached which is comparable to that of the NP-based strain gauges elaborated from colloidal solutions. 13,14,17,19,20 As previously suggested in the literature, [13][14][15][16][17][18][19][20] the exponential increase of DR/R with tensile strain e which is observed in Fig. 3(b) is consistent with the exponential dependence of tunnelling resistance on the interparticle separation distance.…”

“…1 For the last ten years, the research on piezoresistive transducers has mainly been focused on the use of nanomaterials to optimize sensitivity, power consumption, and sensor miniaturization. For instance, Si nanowires, [2][3][4] carbon nanotubes, [5][6][7] graphene, [8][9][10] MoS 2 , 10 SiC nanoribbons, 11 Ag nanowires, 12 and metallic nanoparticle (NP) assemblies [13][14][15][16][17][18][19][20] have been exploited at the laboratory scale to achieve very large gauge factors (GFs) which rival the state-of-the-art bulk Si gauges. Although the use of nanomaterials has attracted a lot of attention in the literature these past few years, many technological obstacles (manipulation of individual nanostructures, complexity of the process, sensor reproducibility, etc.)…”

“…(4). According to the simplified electron tunneling model which was used in many different recent studies on NPbased strain gauges, the relative resistance change with strain of the tunneling contribution R T can be expressed as 13,14,19,20 …”

“…According to the literature, the high sensitivity of metallic NP strain gauges is attributed to the modulation, with respect to the strain, of electron tunnelling events between neighbouring NPs. [13][14][15][16][17][18][19][20] These metallic NP strain sensors are usually elaborated from colloidal solutions which are transferred to a variety of substrates by inkjet printing, airbrush spraying, layer-by-layer deposition, centrifugal method, or convective self-assembly. [13][14][15][16][18][19][20] However, such processes are unconventional for the silicon industry, and therefore, they cannot address traditional MEMS applications.…”

Internal triaxial strain imaging of visibly opaque black rubbers with terahertz polarization spectroscopy

“…In particular, because it is well known that the strain localization leads to failure through cracks, 2,3 the evaluation of the spatial strain distribution is quite important. To date, numerous techniques have been introduced for evaluating the strain, for example, by using X-ray, 4,5 visible light, 6 and electric 7 and optical strain gauging. 8 The strain evaluation techniques based on visible light such as photoelasticity 9,10 and digital image correlation (DIC) techniques 11,12 have a clear advantage compared with other methods.…”