Zhejiang University, China
Title: Tuning wave propagation in soft phononic crystals via large deformation and multi-field coupling effect
Biography: Weiqiu Chen
Soft electroactive materials can deform to a large extent in a reversible way under mechanical or electrical loading. This unique ability makes them very attractive to be the material candidates for designing smart and tunable devices, structures and systems. We will report some recent advances in tunable soft Phononic Crystals (PCs) in which waves can be manipulated according to the application purpose. In particular, attention will be paid to a simple one-dimensional soft PC cylinder made of dielectric elastomer. A series of mechanically negligible soft electrodes are placed periodically along the dielectric elastomer cylinder and hence the material is actually uniform in the undeformed state as well as in the uniformly pre-stretched state subjected to a static axial force only. Th e periodicity of the structure that is required for a PC is acquired via two diff erent loading paths. In the fi rst path, we fi x the ongitudinal stretch and then apply an electric voltage over any two neighboring electrodes. In the second path, the axial force is kept unchanged and then the voltage is applied. Th e outstanding performance regarding
the band gap (BG) property of the soft dielectric PC is well demonstrated through the comparison with the conventional design
adopting the hard piezoelectric material. We also illustrate that the snap-through instability of the axially free PC cylinder made of a generalized Gent material may be used to trigger a sharp transition in the BGs.