Zeytun Karaman Cansu, Raman Venkatesan Thulasinath, Nüesch Frank A, Opris Dorina M
Laboratory for Functional Polymers, Swiss Federal Laboratories for Materials Science and Technology Empa, Ueberlandstr. 129, CH-8600 Dübendorf, Switzerland.
Institute of Chemical Sciences and Engineering, Ecole Polytechnique Federale de Lausanne, EPFL, Station 6, CH-1015 Lausanne, Switzerland.
ACS Appl Mater Interfaces. 2025 Jul 2;17(26):38504-38514. doi: 10.1021/acsami.5c06610. Epub 2025 Jun 17.
Dielectric elastomer actuators (DEAs) are soft transducers well-suited to precise motion applications in robotics and prosthetics. However, low dielectric permittivity or very soft elastomers result in a high operating voltage or low force output. These issues can be mitigated using high dielectric permittivity elastomers in a stack actuator. To optimize electromechanical performance, we synthesized high-permittivity polysiloxanes with varying ratios of ethyl sulfonyl thioether and butane thioether groups. The best material exhibited a dielectric permittivity of 16.2 at 10 kHz and 25 °C, a low conductivity of 1.8 × 10 S cm, and a large lateral actuation strain of 13% at a low electric field of 8.2 V μm (1 Hz, 900 V), whereas state-of-the-art nitrile- and methyl sulfonyl-functionalized polysiloxane required electric fields exceeding 20 V μm for the same actuation. A stack of five single-layer actuators using this material as the dielectric exhibited a thickness strain of 4.5% at a low electric field of 14.5 V μm (1 Hz, 1600 V). The stack actuator showed stable performance at 1200 V over various frequencies, including 5 and 10 Hz, and maintained a reversible actuation over 4000 cycles at 1 Hz.
介电弹性体驱动器（DEAs）是一种软换能器，非常适合用于机器人技术和假肢中的精确运动应用。然而，低介电常数或非常柔软的弹性体会导致高工作电压或低力输出。使用堆叠式驱动器中的高介电常数弹性体可以缓解这些问题。为了优化机电性能，我们合成了具有不同比例乙磺酰硫醚和丁烷硫醚基团的高介电常数聚硅氧烷。最佳材料在10 kHz和25°C下的介电常数为16.2，电导率低至1.8×10 S cm，在8.2 V μm的低电场（1 Hz，900 V）下横向驱动应变高达13%，而目前最先进的腈基和甲基磺酰基功能化聚硅氧烷在相同驱动下需要超过20 V μm的电场。使用这种材料作为电介质的五个单层驱动器堆叠在14.5 V μm的低电场（1 Hz，1600 V）下表现出4.5%的厚度应变。该堆叠式驱动器在1200 V的各种频率（包括5和10 Hz）下表现出稳定的性能，并在1 Hz下经过4000次循环仍保持可逆驱动。
