High-Precision Transdermal Drug Delivery Device with Piezoelectric Mechanism

Piezoelectric (PE) micropumps are distinguished by their high precision, absence of electromagnetic radiation, and straightforward construction principles, making them vital in biomedicine and drug delivery. Integrating PE micropumps with microneedles creates a stable, accurate transdermal drug delivery device capable of finely tuning dosage, rate, and targeting. This paper proposes such a device, combining a PE micropump with a microneedle array. Initially, the internal flow dynamics of the PE micropump and the microneedle forces were analyzed through simulations. Subsequently, the optimal size for the PE micropump was established via parameter optimization experiments. Comprehensive tests were conducted to assess the device’s output performance, including frequency response, voltage characteristics, and flow resistance properties. Key performance indicators evaluated were output flow, pressure, and resolution. Experimental findings revealed that with a constant driving voltage, the PE micropump’s output flow and pressure initially increase and then decrease as the operating frequency rises. Conversely, with a fixed operating frequency, output flow and pressure positively correlate with the driving voltage, showing a near-linear relationship. Under stable working conditions, output pressure and flow are inversely proportional. The PE micropump achieves an output flow of 4.0 mL/min and a pressure of 35.7 kPa at 70 V and 80 Hz. The output flow rate and pressure of the device with the integrated microneedle array are 3.5 mL/min and 30 kPa, the minimum flow resolution is 0.28 μL, exemplifying the potential applications of PE micropumps and microneedles in the field of biomedicine.