A Fast Response, High Flow Rate, Low Power Consumption Pneumatic Proportional Valve for Medical Ventilators Driven by a Piezoelectric Bimorph

In recent years, pneumatic proportional valves have become increasingly prevalent in ventilators, particularly proportional solenoid valves. However, these traditional valves face challenges, including a slow response, being prone to overheating from long-term work, and high power consumption. This study presents the development of a fast response, high flow rate, and low power consumption pneumatic proportional valve specifically designed for medical ventilators. Utilizing a piezoelectric bimorph as the actuator, we innovatively eliminate movable components such as springs while ensuring effective sealing of the valve. A support structure was designed to enhance the mechanical performance of the piezoelectric bimorph. A testing platform was established to rigorously assess the valve’s performance. The results indicate that the valve can achieve a maximum output flow rate of approximately 130 L/min at an input pressure of 4 bar, with a hysteresis rate of 25.3%, a response time of under 10 ms, and a power consumption of just 0.07 W. Furthermore, a comparative analysis with existing commercial proportional solenoid valves demonstrated that it has superior performance in terms of response speed, flow rate, and power efficiency. The piezoelectric proportional valve developed in this study holds the potential to replace conventional proportional solenoid valves, significantly enhancing the response speed of ventilators, reducing their overall power consumption, and facilitating the development of portable ventilators.