*Article* **3-D Design and Simulation of a Piezoelectric Micropump**

#### **Seyed Amir Fouad Farshchi Yazdi, Alberto Corigliano \* and Raffaele Ardito**

MEMS Modelling and Design Group, Department of Civil and Environmental Engineering, Politecnico di Milano, 20133 Milan, Italy; seyedamir.farshchi@polimi.it (S.A.F.F.Y.); raffaele.ardito@polimi.it (R.A.)

**\*** Correspondence: alberto.corigliano@polimi.it; Tel.: +39-0223994244

Received: 14 February 2019; Accepted: 11 April 2019; Published: 18 April 2019

**Abstract:** The objective of this paper is to carefully study the performances of a new piezoelectric micropump that could be used, e.g., for drug delivery or micro-cooling systems. The proposed micropump is characterized by silicon diaphragms, with a piezoelectric actuation at a 60 V input voltage, and by two passive valves for flow input and output. By means of a 3-D Finite Element (FE) model, the fluid dynamic response during different stages of the working cycle is investigated, together with the fluid–structure interaction. The maximum predicted outflow is 1.62 μL min−1, obtained at 10 Hz working frequency. The computational model enables the optimization of geometrical features, with the goal to improve the pumping efficiency: The outflow is increased until 2.5 μL min−1.

**Keywords:** piezoelectric material; multiphysics simulation; finite element method (FEM); fluid–structure interaction (FSI); micro electromechanical systems (MEMS)
