Article pubs.acs.org/JPCC
Influence of the Humidity on Nanoparticle-Based Resistive Strain Gauges Lucas Digianantonio,† Mélanie Gauvin,† Thomas Alnasser,† David Babonneau,‡ Benoit Viallet,† Jérémie Grisolia,† Guillaume Viau,† Alessandro Coati,§ Yves Garreau,§,∥ and Laurence Ressier*,† †
LPCNO, INSA-CNRS-UPS, 135 avenue de Rangueil, 31077 Toulouse, France Institut P’, Département Physique et Mécanique des Matériaux, UPR 3346 CNRS, Université de Poitiers, 11 Boulevard Marie et Pierre Curie, 86962 Futuroscope Chasseneuil, France § Synchrotron Soleil, L’Orme des Merisiers Saint-Aubin, 91192 Gif-sur-Yvette, France ∥ Université Paris Diderot, Sorbonne-Paris-Cité, MPQ, UMR 7162 CNRS, Paris Cedex 13, France ‡
S Supporting Information *
ABSTRACT: The strong impact of humidity over the performances of gold colloidal nanoparticle (NP)-based resistive strain gauges is quantified and investigated by coupling electro-mechanical and in situ small-angle X-ray scattering measurements. When the relative humidity increases from 0% to 60%, the electrical resistance at rest of the NP-based sensors increases by 40%, and their sensitivity increases by 50%. This is accompanied by a rise of about 1% to 2% in the center-tocenter distance between neighboring NPs and by an increase of the compactness of the NP assembly, possible evidence of a reorganization of the NPs. An encapsulation solution, based on alternating polymer and alumina layers, stabilizes the performances of the NP-based strain gauges for strains up to 0.4%. This approach could be extended to other flexible NP-based devices.
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INTRODUCTION Over the past few years, highly sensitive nanoparticle (NP)based strain gauges have been developed.1−6 This new type of strain sensor exploits the exponential dependence of the electrical tunnel resistance between colloidal NPs assembled on a flexible substrate within the interparticle distance variation. These sensors present additional strong advantages: a low electrical consumption due to their high electrical resistance at rest (tunable between 100 kΩ and 10 MΩ), which is very interesting for wireless applications for instance, and a high capability of integration thanks to the reduced size of their active area (
