Evaluation of a Bionical Piezoelectric Micro-Flapper for Enhanced Fluid Flow Applying Numerical Simulations and Wavelet Transforms

We present a novel concept of a micropump that overcomes typical challenges such as size, integrability and plugging. It is based on the biological approach of fish locomotion, which evolved as the principle in nature for efficient transfer of momentum from a body to a fluid. Nature proofs that this wavelike motion of a flexible long body with increasing amplitude towards the tail, called undulation, works for all scales and frequencies, in gases as well as in liquids. The technical implementation is a thin bending beam with large lateral extensions, similar to the tail fin of a fish. As excitation method a piezoelectric bimorph concept with segmented top-electrodes is chosen. In order to evaluate the generated fluid flow we introduce a sophisticated methodology making use of wavelet transforms and investigations of the local power densities at the fluid structure interface based on simulations and measurements. This way the flapper's efficiency can be assessed quickly, allowing for a comprehensive comparison of various designs, excitations and a benchmark with the natural archetype.