Analysis of annularly excited bossed diaphragm for performance enhancement of mechanical micropump

Abstract

Piezo actuated mechanical micropumps find extensive application in microfluidic devices for precise delivery of the fluids. The deflection of the diaphragm dramatically influences the performance of the mechanical micropump. The present work emphasises a novel method of annular excitation of the diaphragm to enhance the volumetric performance of the micropump. The proposed work incorporates a bossed diaphragm excited through a novel approach of annular excitation. The amplified piezoelectric actuator is used as a primary source of actuation. In the present work, theoretical and finite element methods are considered to analyse the deflection behaviour of the bossed diaphragm under central and annular excitation. Experimental characterisation is carried out to validate the results obtained from finite element analysis. The annular excitation of the bossed diaphragm delivers a higher range of deflection when compared with the conventional central excitation. The maximum simulated deflection of about 1998.4 µm is achieved with an annularly excited bossed diaphragm at 150 V, 45.5 Hz, which is far superior to the deflection range achieved with a conventional centrally excited bossed diaphragm with the deflection of 725.91 µm at 150 V, 9.96 Hz. The corresponding experimental deflection of annularly excited and centrally excited bossed diaphragm is about 1953.4 ± 8.00 µm at 50 V, 43.5 Hz and 717.99 ± 4.00 µm at 150 V, 9.5 Hz. © 2022 Elsevier B.V.