Possibilities of Artificial Muscles Using Dielectric Elastomers and their Applications

Abstract

The recent developments in dielectric elastomers (DE) are spectacular. Currently, a DE as an actuator, 0.15 g of acrylic sandwiching SWCNT electrodes, is capable of lifting a weight of 8 kg by more than 1 mm at a speed of 88 msec. In the near future, DE motors could be used to drive electric vehicles. Moreover, the DE can be used as a high-efficiency sensor with the same structure. With a diameter of 20 mm and a thickness of 0.5 mm, it can accurately measure pressure from several kg to 150 kg. In addition, reversing this DE actuator (DEA) movement also enables high-efficiency power generation. In other words, when the DEA is stretched or pushed, it generates electric power. Single wall nanotubes (SWCNTs) were used as an electrode, and an acrylic DE power generation cartridge with a diameter of 80 mm was used. When the center of the DE power generation cartridge is pushed by about 15 mm, a power of 33.6 mJ is generated. Using these two DE cartridges, it was possible to charge a secondary battery through a DC converter. In addition to this power generator, practical research and development of power generation using wave power, wind power, waste heat, and fluids (ocean currents, water currents, etc.) is progressing. In this paper, we have described state-of-the-art DEAs, DE generators (including the case that the power generated locally by microgenerators are consumed locally), and DE sensors and explained their usefulness.

Examination of factors to improve the performance of dielectric elastomer transducers and their applications

“…Materials studied as elastomers for DEs are silicone, acrylic, polyurethane, fluorosilicone, fluoroelastomer, polybutadiene, isopylene, hydrogenated nitrile rubber (HNBR) [8,17,18,20,21].…”

“…As a method of softening the elastomer film, it is possible to increase the amount of crosslinking agent by cutting one of the double bonds or performing both and adjusting the hardness [17,18]. Figure 3 shows the SS curve of HNBR ver.1, HNBR ver.3, and HBR ver.…”

“…A high voltage is required to drive the DEA, and the normal voltage must be made to a high voltage using the Cock Croft Walton Circuit (booster circuit) [17,48]. Figure 7 shows an example of a booster circuit that drives a sheet-type DEA vibrator in a game [17].…”

“…A high voltage is required to drive the DEA, and the normal voltage must be made to a high voltage using the Cock Croft Walton Circuit (booster circuit) [17,48]. Figure 7 shows an example of a booster circuit that drives a sheet-type DEA vibrator in a game [17]. Most of the circuits shown in the figure are equalizer circuits for controlling the audio circuit and sound built into headphones.…”

“…The DE also functions as a sensor and generator. Therefore, the most promising candidate for EAP technology can be considered as DEs [8,17,18]. In 1991, Pelrine and Chiba at the Stanford Research Institute (SRI) in the United States embarked on the first research and development projects on DEs [7].…”