| In response to the problem of slow effectiveness of traditional treatment methods such as oral and intravenous injection,which have side effects on healthy parts of the patient’s body,a new type of implantable micropump is needed.It can optimize the drug distribution,making the treatment process more accurate and reliable.This article presents two structural design schemes for PZT piezoelectric micropumps,including planar diffuser/nozzle tube piezoelectric micropumps and piezoelectric micropumps with sliding cylindrical check valves.The principles of pumps are analyzed based on the inverse piezoelectric effect and fluid mechanics.On this basis,a valveless micropump structure model was constructed using Comsol to study the mechanical and piezoelectric characteristics of the pump,analyze the impact of diffuser/nozzle tubes size on the output performance of the pump,optimize its structural size,and simulate the role of a sliding cylindrical check valve.We studied the fabrication of micropumps using processes such as PDMS-glass bonding and photolithography,and designed and manufactured packaging structures using 3D printing technology to achieve the packaging of micropump test.At room temperature,signal generators and Olympus microscopes were used to study the flow characteristics of micropumps.The experimental results show that when the driving voltage frequency is 1 Hz and the amplitude is 10～20 V,the flow range of the planar diffuser/nozzle tubes piezoelectric micropump is 0.09～0.74 μL/min;Under the same conditions,the flow range of the piezoelectric micropump with a sliding cylindrical check valve is 0.43～2.26 μL/min,analysis shows that the flow rate of a valved micropump is three times that of a valveless micropump.The experimental results show that both the diffuser/nozzle tubes and the sliding cylindrical check valve have certain check functions. |
