Optical strain detectors based on gold/elastomer nanoparticulated films

The application of two different optical effects is demonstrated for the detection of strain applied to elastomeric films. On one hand, dense coatings made of silica-coated gold nanoparticles (Au@SiO2 NPs), which are built up onto poly(dimethylsiloxane) (PDMS) elastomeric films, using the layer-by-layer(LbL) method, provide intense surface plasmon resonance (SPR) absorption. On the other hand, polystyrene spheres can be deposited as ordered monolayers to create patterned PDMS films with well-defined light diffraction. Both effects were used to monitor the structural damage of such PDMS films upon stretching, remaining both physical phenomena (absorption from the gold film and diffraction from the ordered structure) active for optical sensing applications in the early detection of structural damage in critical infrastructures.