Soft, Low Complexity Dielectric Elastomer Generators

Abstract

The global demand for renewable energy is forecast to grow rapidly over the next 25 years [1]. A class of variable capacitor power generators called Dielectric Elastomer Generators (DEG), show considerable promise for harvesting from previously unviable sources. This is because they can be directly coupled to large broadband motions without gearing, while maintaining a high energy density, and they have few moving parts, and are highly flexible. At the system level DEG cannot currently realize their full potential for flexibility, simplicity and low mass because they require rigid and bulky external circuitry and often need a secondary high voltage energy source; there is a lack of modelling tools for system level optimization; and there is a lack of experimental data from explicitly described DEG systems. The objectives of this thesis are to provide solutions to these issues. First, system level DEG models with the dynamic electrical systems were developed and experimentally validated. Then the generalized Self-Priming Circuit (SPC) was introduced, an external circuit that enables DEG to operate in a wide range of conditions without a secondary high voltage energy source. These systems do not require an external high voltage energy source because they have the ability to boost their voltage from consumer battery levels up to kilovolt levels by accumulation of generated energy. Generalized SPC were then optimized for voltage boosting and energy production using the system level models. Finally, integrated self-priming systems were introduced. The SPC in these systems was integrated onto the DEG membrane using a flexible electronics technology called Dielectric Elastomer Switches (DES), so that no rigid and bulky external electronics were required. Highly explicit experimental analysis of each system was carried out. These contributions resulted in the publication of three journal articles, two provisional patents, and three conference articles. This work presents the opportunity to produce DEG systems with greater autonomy, softness, simplicity, energy density, and lower cost than previously. With further developments of DES, more complex systems with these benefits will be possible.