Investigations on the application and control of shape memory alloy NiTinol actuators

Abstract

Electrical Mechanical System (MEMS). Among them, Shape Memory Alloys (SMAs) exhibit the ability to recover large mechanical deformation upon heating and cooling. These properties make them well suited for various applications in actuation systems. In this thesis, shape memory alloy, NiTinol (Nickel Titanium Naval Ordnance Laboratory) has been selected due to its unique mechanical properties like Shape Memory Effect (SME) and Super Eleastic Effect (SEE). Various experiments have been carried out to study the change in mechanical properties with respect to temperature. Based on the results it was found that NiTinol in the form of wire is used to control the vibration of a cantilever beam and NiTinol in the form of a spring is used for automatic actuation of fire sprinkler. In this research work, the vibration of a cantilever beam was controlled by hinging 0.5mm diameter NiTinol wire at its free end. NiTinol wire was stretched at both ends inclined to make its strain 2% and fix firmly on vertical column. By supplying electrical current through it, newline