Colour-changing strain sensors
Responsable : Thomas Maurer, ICD/LNIO
Towards a novel generation of strain sensors integrated into matter
Some nano deformations visible to the naked eye thanks to innovative integrated optical nanosensors
Metal NanoParticles (MNPs) are known to support Localized Surface Plasmons (LSP) that are highly sensitive, not only to the MNPs chemical composition or size, but also to interparticle resonant coupling when the gap between MNPs is less than the nanoparticle diameter.
This open the way to new smart sensors integrated into matter: some color-changing plasmonic strain sensors based on the spectral variation of plasmonic coupling versus interparticle distances when stretching a composite film that incorporates MNPs.
A fruitful collaboration between the LNIO and Laval University (Québec) has been started to self-organize dense Au NPs rings onto elastomeric film in order to increase sensitivity.
The first prototype, made in collaboration with Univ. Geneva and Univ. Calabria, consisted of 23 nm Au NPs immobilized onto a PDMS substrate with an average distance of 39 nm between neighbouring NPs.
In this way plasmonic coupling effects become visible and the resulting gold-coated flexible tape can be utilized as a color-changing strain sensor.
As nanoparticules act as nanosensors able to predict deformations (SHM), some potential applications could be found in packaging, nanoimprint or industrial paint.
> 1 patent relative to plasmomechanics
- Non-contact sensors
- Large deformations
- Direct integration into matter