Inflation of dielectric elastomer membranes for energy harvesting: prestretch, rupture, dielectric breakdown, and the electromechanical instability
Sprache des Vortragstitels:
SPIE 2011 Smart Structures/NDE
Sprache des Tagungstitel:
Since dielectric elastomers are considered as promising candidates
for energy harvesting applications, efforts are increasing to assess the maximal amount of energy that can be generated with a specific material. Recently theoretical works identified dielectric breakdown, rupture and the electromechanical instability as mechanisms limiting the amount of energy that can be electromechanically converted. Nevertheless only sparse experimental data on these material limits is available.
Here we present a fully computer controlled laboratory scale generator setup, where compressed air is used to inflate a dielectric elastomer membrane, a favorable geometry for biaxial deformation, which is achieved at the top region of the balloon shaped membrane. All necessary mechanical and electrical parameters are in situ monitored during inflation of the membrane with different applied voltages. This allows the construction of limiting lines in work conjugate plots confining an area of safe operation states that define the maximal specific energy that can be harvested. Different amounts of pre-stretch of the elastomer
membrane before inflation are used to examine possible operating
conditions of practical devices. In this work we used the common
3M™VHB™4910 polyacrylic elastomer tape but our method and setup
can be readily used to extract the material limits of all kinds of dielectric elastomers which could be interesting for energy harvesting applications.