Possibility of a Portable Power Generator Using Dielectric Elastomers and a Charging System for Secondary Batteries

Abstract

Energy generation using dielectric elastomers (DE) has received a great deal of attention due to their light weight, low cost, and high efficiency. This method is an environmentally friendly system that generates electricity without emitting carbon dioxide and without using rare earths, and can contribute to the reduction of global warming. However, this DE system is expected to be used for wearables, such as shoe power generation, because it is not yet possible to make an energy generation element of a very large size. The problem is that this small DE generator can only generate a small amount of energy at one time. Therefore, in order to increase energy generation efficiency, it is necessary to use a material with higher conductivity for the DE electrode. Moreover, since DE energy generation is output at a high voltage, a circuit capable of stepping down with high efficiency is required in order to use this power for ordinary electric appliances. In addition to this, a circuit that can charge the secondary battery with high efficiency from the surplus power obtained by energy generation is also required. However, these are still technically difficult and have hardly been studied so far. We identified a highly efficient step-down circuit using two diaphragm-type DEs with a diameter of 8 cm, dropped 3000 V to 3.3 V, and succeeded in charging the secondary battery. The possibility of wearable or portable energy generation was shown in a commercial manner.

Possibilities of Artificial Muscles Using Dielectric Elastomers and their Applications

“…This sensor was very flexible and comfortable to wear and was well-received by the elderly. [46, 50, 59, 61 -68, 70 -72, 74, 75], and electrical circuit design [59,[76][77][78]. This chapter discusses actual research and development cases of power generation using renewable energy.…”

“…A portable type of DEG and a rechargeable secondary battery system that can be used in the event of a disaster or earthquake have recently been developed [59]. Figure 18 shows a small DEG device.…”

Recent Development of Dielectric Elastomer Transducers and Potential Applications

“…However, general step-down circuits cannot handle high-voltage, intermittent output of electrical energy. As a way to overcome this, a step-down/accumulator circuit using multiple high-voltage capacitors is effective [25]. Figure 3 is a block diagram of a secondary battery charging circuit developed for small DEG devices.…”

“…First, push the acrylic rod of the DEG unit about 15 mm, and then drive it continually about 20 to 30 times to obtain a stable voltage of 3.3 V. Furthermore, by increasing the capacitance of the storage capacitor in the charging circuit, it is possible to supply current up to 100 mA [25]. Changing the elastomer material depending on the application is recommended.…”

Dielectric Elastomer Multi-Sensors and Tactile Actuators for Robot Fingers in Human-Robot Interaction

“…Chiba et al demonstrated that a 0.15 g DE could lift an 8 kgf weight by more than 1 mm in 88 ms, and they also demonstrated the great potential of ultralightweight and ultra-high performance DE motors [22,23]. They also developed a portable DE generator and showed that it is possible to charge a secondary battery at the same time [24].…”