title: Investigation into the electromechanical properties of dielectric elastomers subjected to pre-stressing.
abstract: Dielectric elastomers (DEs) are being exploited for biological applications such as artificial blood pumps, biomimetic grippers and biomimetic robots. Generally, polyacrylate and silicone rubber (SR) are the most widely used materials for fabricating DEs in terms of mixing with other polymers or compounding them with highly dielectric particles. Furthermore, pre-stretch offers an effective approach to increasing actuated strain and dielectric strength and eliminating 'pull-in' instability. In the work described here, a comparison in electromechanical properties was made between SR/10% barium titanate (BaTiO3) and commercial VHB 4910. Trends in these dielectric parameters are shown graphically for variation in pre-stretch ratio (λpre). It was found that permittivity of SR/10% BaTiO3 was independent of frequency, whereas permittivity was frequency-independent due to the polarization of polymer chains. The maximum deformation and the coupling efficiency for SR/10% BaTiO3 can be achieved at a pre-stretch ratio between 1.6 and 1.9. For VHB 4910, they can be obtained in the pre-stretch ratio range from 2.6 to 3.0. A maximum energy density of 0.05MJ/m(3) was achieved by SR/10% BaTiO3 (λpre=1.6) and VHB 4910 (λpre=3.4). The findings provide an insight into critical pre-stretch ratios required for a range of applications of DEs based on silicone and the commercially available polyacrylate VHB 4910.
authors: Centre for Elastomer Research (CER), Focas Research Institute, Dublin Institute of Technology, Dublin 8, Ireland. Electronic address: liang.jiang@mydit.ie.
authors: Liang
authors: L
authors: Jiang
authors: The Applied Electrochemistry Group (AEG), Focas Research Institute, Dublin Institute of Technology, Dublin 8, Ireland.
authors: Anthony
authors: A
authors: Betts
authors: Department of Mechanical Engineering, Dublin Institute of Technology, Dublin 1, Ireland.
authors: David
authors: D
authors: Kennedy
authors: Centre for Elastomer Research (CER), Focas Research Institute, Dublin Institute of Technology, Dublin 8, Ireland.
authors: Stephen
authors: S
authors: Jerrams
mesh_terms: D017609:Barium Compounds / Q000737:chemistry; D040761:Biomimetic Materials / Q000737:chemistry; D032701:Biomimetics / Q000379:methods; D020724:Elastomers / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry; D012826:Silicone Elastomers / Q000737:chemistry; D014025:Titanium / Q000737:chemistry
chemical_list: D017609:Barium Compounds; D020724:Elastomers; D011108:Polymers; D012826:Silicone Elastomers; C024547:barium titanate(IV); D014025:Titanium
keywords: Dielectric elastomers; Energy density; Pre-stretch; Pull-in instability; Silicone rubber/BaTiO(3); VHB 4910