Silver thin films generated by Pulsed Laser Deposition on plasma-treated surface of silicones to get dielectric elastomer transducers

Abstract

Due to their high stability over a wide range of temperature or moisture, silicone-based dielectric elastomer transducers (DETs) are of great scientific interest. In this regard, highly stretchable silicone elastomer films were prepared on the basis of a high molecular weight (Mn = 380,000 gmol−1) polydimethylsiloxane‑α,ω‑diol (PDMS) and stabilized by condensation crosslinking at room temperature, process which was monitored by IR spectroscopy. The obtained films were treated in oxygen radio-frequency (RF) plasma at 50 and 60 W for 3, 6 and 12 min. Depending on plasma treatment conditions, different surface morphologies were obtained, as evidenced by the atomic force microscopy (AFM), while chemical modifications were investigated by X-ray photoelectron spectroscopy (XPS). The elastomer films activated on both sides were further used as substrate for silver electrode deposition through Pulsed Laser Deposition (PLD) to obtain DETs. The deposited films were investigated from the point of view of mechanical and electrical behavior in normal state and after repeated mechanical stresses to assess the suitability of silver layer as stretchable electrode. Moreover, the achieved DETs were successfully tested in terms of actuation displacement.