Flexible nanocomposites with all-optical tactile sensing capability

Plasmonic resonators have generated much interest in recent years due to their ability to localize optical energy into thin continuous metallic regions. We present the integration of such resonators into flexible polydimethylsiloxane-gold nanocomposite materials that couple light efficiently, in order to prepare a totally optical layout for tactile sensors, able to detect low applied pressure forces. The development of plasmonic nanostructured resonators of thin gold layers onto polydimethylsiloxane is achieved using light texturing. In particular, this technique creates uniform patterns of gold nanoparticles forming quasi continuous gold thin layers behaving as plasmonic resonators. The excitation of the resonators and the detection of the signal after the application of the pressure are done through optical fibers avoiding electrical connections or circuits embedded into the elastomer. The proposed totally optical tactile sensor is easily processable and ideal for upscaling oriented towards humanoid robotics and biocompatible elastomeric human interface skin prostheses.