Time-Resolved Plasmonics used to On-Line Monitor Metal/Elastomer Deposition for Low-Voltage Dielectric Elastomer Transducers

Compliant hetero-nanostructures provide access to nano-photonics, flexible electronics, and artificial muscles. These nanometer-thin polymers and metals are regularly predicated on molecular beam deposition-a technique that leads reliably to homogeneous films and enables the precise in situ monitoring of forming nanostructures. Herein, it is demonstrated that spectroscopic ellipsometry can be used to on-line monitor film formation with a sub-nanometer resolution and the evolution of the related optical properties of the hetero-nanostructure. The data recorded include plasmonic fingerprints of Au islands as well as film formation on self-assembled polydimethylsiloxane (PDMS). Bi-functionalized thiol-PDMS, tailored for thermal deposition, serves as a self-assembled adhesion layer for Au electrodes. Suppressed localized plasmonic activity indicates the formation of a homogeneous Au film on thiol-PDMS and wrinkled Cr/PDMS, contrary to the well-known establishment of Au islands on bare PDMS. The tailored hetero-nanostructures based on Au/thiol-PDMS and Au on wrinkled Cr/PDMS adhesion layers enable the fabrication of stretchable electronics and low-voltage dielectric elastomer sensors and actuators for artificial muscles and tunable optics.