Investigation on Laser assisted actuation of shape memory alloy based micro-valve

This research highly focuses towards development of a Shape Memory Alloy based micro valve and actuation using LASER. Numerous Micro valve designs have been reported with a variety of actuation mechanisms such as piezoelectric, silicon rubber, etc. [1], but the use of these micro valves have been limited. Here LASER is used as actuation medium because of noncontact type and low power energy density source. The micro valve is designed and fabricated to control small amounts of fluid flow of the order of μL/sec. Single way trained NiTi Shape Memory Alloy is used in this micro valve. EDX test and DSC test has been performed to get details of properties of NiTi SMA. In the LASER actuation work, detailed parametric studies have been performed by actuating the one way trained SMA at various Laser fluence, actuation time and spot diameter of Laser .Scanning Electron Microscope test has been performed to check for ablation. A micro-valve array for fluid flow control on macroscopic level is described. The micro-valve array is based on innovative design such that flow rate across micro-valve array can be varied with number of micro-valve opened with each micro-valve is laser actuated and spring returned. The actuation of SMA using LASER shows that the maximum deflection obtained for optimum LASER fluence of 25.48mJ/cm² is 7.29 mm, The flow measurement was performed using an air meter at pressure difference ranging from 1KPa to 5KPa with minimum rate of flow 325 μL/sec.