Minimization of losses in natural rubber films for dielectric energy harvesters

Description

Wave energy harvesting is a comparably new and increasingly developing branch of the sustainable energy sector. Being versatile in their design and attractively simple in their working principle, dielectric elastomer generators (DEGs) are known as a promising class of wave energy harvesters. DEGs are generally soft elastomeric capacitors that change their capacitance upon stretching. The maximum efficiency of such device is estimated to be up to 42 % (Ahnert et al. 2011), and during the field test it can produce more than 0.1 J/g of an active dielectric material per harvesting cycle (Kornbluh et al. 2012). However, efficiency and energy output of a DEG depends on the properties of dielectric elastomer material, generator design, type and quality of electrode, charging voltage, strain levels, cycle length and some other factors. Nevertheless, current harvester prototypes utilize dielectric elastomer membranes that are lacking all the necessary properties to make DEG economically viable (Graf et al. 2014). Therefore, elastomeric material designed specially for the DEG application is in demand. Natural rubber (NR) films has already been utilized in DEGs (Kaltseis et al. 2014), and NR outperformed other elastomeric materials often used in such devices in terms of dielectric and viscoelastic losses. The present study is focusing on comparing dielectric loss properties of different NR types by using broadband dielectric spectroscopy, and shows the possibility to minimize high losses by the addition of small amounts of nanodiamond filler to the rubber matrix. Moreover, small- and large-scale viscoelastic loss properties of the rubber and rubber-nanodiamond composites are investigated by means of dynamic mechanical analysis and cyclic tensile loading.

Aikajakso	15 toukok. 2017
Tapahtuman otsikko	9th International Exergy, Energy and Environment Symposium
Tapahtuman tyyppi	Conference
Sijainti	Split, KroatiaNäytä kartalla