Characteristics of Thermally Actuated Pneumatic Proportional Pressure Valves and Their Application

Two types of pneumatic proportional pressure valves that use microelectromechanical system-based thermally actuated chips—a one-chip valve and a two-chip valve—are developed. The relative structures, unilateral driving mechanism, design considerations, control method, and experimental results are demonstrated. Under closed-loop control, the pressure curves of the two valves show good linearity; the rise time of the one-chip valve is about 50 ms and that of the two-chip valve is less than 40 ms. The experimental results reveal that the thermally actuated pneumatic pressure valves meet the general requirements of some industry applications. An actuator driven by the developed two-chip valve is introduced briefly as an application example, and the voltage–displacement and voltage–force output characteristics of the actuator are demonstrated via a test. The test results demonstrate the possibility and feasibility of realising a new type of thermally actuated actuator with a large force output (max. 400 N) and limited displacement (max. 1.8 mm). The designed thermally actuated actuator can be used as a driving device independently or as a pilot stage for other pneumatic control valves.