High-precision transdermal drug delivery enabled by a dual-pump parallel valveless piezoelectric micropump integrated with hollow microneedles.

Abstract

Transdermal drug delivery (TDD) system based on piezoelectric micropumps is a novel route of drug delivery that is wearable and highly patient-compliant. The advantage of valveless micropumps, such as their simple structure, high reliability and low cost, have been investigated in comparison to valve-based micropumps. However, the flow pulsation and backflow effect of valveless pump can reduce the controllability and precision of the system. Here, a TDD wearable device integrated with a dual-pump parallel valveless piezoelectric micropump and hollow microneedle array is presented, which is fabricated by means of 3D printing technology. The simulation analysis and experimental results indicate that the dual-pump parallel micropump with asynchronous driving can achieve a full forward flow and reduces the influence of flow pulsation on the system's stability, showing the excellent controllability and high precision of the device. The output flow rate and pressure of the micropump can be controlled by the driving signal, which are about 1.61 mL/min and 700 Pa with the sine driving signal of 40 V, 600 Hz. Through animal experiments, we demonstrate that the device can successfully deliver insulin to mice and control blood glucose. In conclusion, this TDD device which potentially provides low-cost and high-precision results than existing technologies, shows considerable promise in wearable drug delivery applications, especially in managing chronic diseases that require long-term treatment.