Artificial Muscles: Dielectric Elastomers Responsive to Low Voltages

• Published in: Macromolecular rapid communications. Vol. 40; no. 16; pp. e1900205 - n/a
• Main Authors: Sheima, Yauhen, Caspari, Philip, Opris, Dorina M.
• Format: Journal Article
• Language: English
• Published: Germany Wiley Subscription Services, Inc 01.08.2019
• Subjects: Actuation; Actuators; Artificial muscles; Breakdown; Chemical reactions; dielectric elastomer actuators; Dielectric properties; Elastic properties; Elastomers; Elastomers - chemistry; Electrochemical Techniques; high permittivity elastomers; high permittivity polysiloxanes; Low voltage; Mechanical properties; Modulus of elasticity; Muscles; Organic chemistry; Permittivity; Storage modulus; Thin films; thiol‐ene addition; Voltage; dielectric elastomer actuators; thiol-ene addition; high permittivity polysiloxanes; high permittivity elastomers; thin films
• ISSN: 1022-1336; 1521-3927; 1521-3927
• DOI: 10.1002/marc.201900205

The lack of soft high‐dielectric‐permittivity elastomers responsive to a low voltage has been a long‐standing obstacle for the industrialization of dielectric elastomer actuators (DEA) technology. Here, elastomers that not only possess a high dielectric permittivity of 18 and good elastic and insulating properties but are also processable in very thin films by conventional techniques are reported. Additionally, the elastic modulus can be easily tuned. A soft elastomer with a storage modulus of E = 350 kPa, a tanδ = 0.007 at 0.05 Hz, and a lateral actuation strain of 13% at 13 V µm−1 is prepared. A stable lateral actuation over 50 000 cycles at 10 Hz is demonstrated. A stiffer elastomer with an E = 790 kPa, a tanδ = 0.0018 at 0.05 Hz, a large out‐of‐plane actuation at 41 V µm−1, and breakdown fields of almost 100 V µm−1 is also developed. Such breakdown fields are the highest ever reported for a high‐permittivity elastomer. Additionally, actuators operable at a voltage as low as 200 V are also demonstrated. Because the materials used are cheap and easily available, and the chemical reactions leading to them allow upscaling, they have the potential to advance the DEA technology. A synthetic pathway to nitrile‐modified polysiloxane elastomers with high dielectric permittivity, which are processable into very thin films, is developed. Because the elastomers actuated at unprecedentedly low voltages, give large actuation, and have an unprecedentedly high dielectric breakdown, they have the potential to revolutionize dielectric elastomer actuator technology.