Design and development of a piezoelectric driven micropump integrated with hollow microneedles for precise insulin delivery

Abstract

A significant rise in diabetes has spurred researchers to develop more painless, patient-friendly, precise therapeutic products for insulin delivery. There is extensive use of valveless micropumps in numerous medical devices since they constitute the key component in the microsystem for fluid control and precision delivery. This study reports a novel integrated insulin delivery device consisting of a valveless piezoelectric-driven micropump, a hollow microneedle array, and a fluid reservoir. At first, a simple, low-cost micropump driven by a piezoelectric disc is fabricated using 3D printing technology. Nozzle/diffuser elements are used instead of any active valves in order to avoid leakage and other complexities. To investigate the viability of the micropump, an analysis of the vibrational performance of the piezoelectric actuator is performed. COMSOL Multiphysics is used to perform the transient analysis of the piezoelectric actuator of the micropump. Further, simulation-based flow analyses are carried out to verify the outcomes of the experimental studies. The experimental results indicate that the maximum flow rate of the micropump is achieved at 400 Hz for insulin. To realize the final aim of this work, an array of hollow SU-8 microneedles is fabricated and then finally integrated with the piezoelectric-driven valveless micropump and fluid reservoir. This integrated insulin delivery device is tuneable and can achieve a maximum flow rate of 120.5 µl min−1 for insulin at 60Vpp, 400 Hz sine wave.