Methods to ease the release of thin polydimethylsiloxane films from difficult substrates

Abstract

Silicone elastomers are used as dielectric electroactive polymers for making actuators, generators, sensors, and as artificial muscles in medical applications. Current requirements in the actuator manufacturing put a strict limitation on the thickness of the elastomers, such that a maximum permissible thickness is around 25-50 μm. The relatively small Young's modulus for these elastomers is a requirement for actuation capabilities. However, peeling and release of such films during manufacture processes are very difficult. To ease the release of the films, techniques such as the use of release agents like surfactants and detergents, incorporating resins in the silicone matrix and grafting/adding low surface energy functionalities to the silicone elastomer have been tested. The methods used are required not to interfere with the Young's modulus and the dielectric permittivity in a negative way. Polysorbate-20, a non-ionic surfactant, fulfills all requirements and gives the lowest peel forces for the films.

The Current State of Silicone-Based Dielectric Elastomer Transducers

“…In the commercial fi lm coating process of Danfoss PolyPower, the major processing issue was high surface energies related to the release of the thin fi lms with micro-structural corrugations from the carrier web. [76][77][78] Unsuccessful release usually caused the detrimental tearing of fi lms. Also, when considering product reliability, the tearing of elastomer fi lms after electrical breakdown is a crucial problem.…”

“…It becomes crucial in processing, as the thickness of the elastomer films is reduced to increase transducer performance. In the commercial film coating process of Danfoss PolyPower, the major processing issue was high surface energies related to the release of the thin films with micro‐structural corrugations from the carrier web . Unsuccessful release usually caused the detrimental tearing of films.…”

The influence of static pre-stretching on the mechanical ageing of filled silicone rubbers for dielectric elastomer applications

“…In this case, post-curing was performed by heating a cured elastomer at 200°C for 4 hours subsequent to the traditional curing procedure, where the most common conditions for dielectric silicone elastomers are curing at ~120°C for 10-30 minutes. [33] To our knowledge the effect of post-curing on, for example, dielectric breakdown strength has never been investigated, since the fraction of volatiles is so low (usually cited at 1-2% by the elastomer supplier) that it seems irrelevant.…”

Polydimethylsiloxane/monomer casting nylon copolymers: Preparation, flame‐retardant properties, and wear‐resistant properties

“…Polydimethylsiloxane (PDMS) has many applications due to its unique properties, which mainly arise from its structure composed of organic grafted methyl group and inorganic SiO bond. These significant properties include great molecular flexibility, low surface energy, good hydrophobicity, flame retardancy, and so forth . PDMS had been widely added to PU to improve mechanical properties and surface and bulk properties .…”