ABSTRACT
As described in chapter 1, the shape memory effect can be exploited to develop thermal actuators through the Joule effect; therefore, we introduce the description of a simple, pneumatic, normally closed (NC), two-way, mono stable mesovalve activated by a threadlike micro-actuator realized with an NiTi alloy. A preliminary prototype allows a wide range of experimental analyses to highlight the most important design defects and, thus, to improve them with an optimized solution. A pneumatic test bench was employed to properly manage some functional parameters and input-output variables of the prototype device. The electric feeding circuit was designed to generate a square wave train with adjustable amplitude, frequency, and duty cycle. Experimental results on the life of the device and different functional tests showed correlations between the behavior of the valve and some physical quantities, i.e., the mass flow rate and the input pressure.
