Laser-Induced Forward Transfer of NiTi for Functional Application

Abstract

Laser-induced forward transfer (LIFT) is a non-lithography, nozzle-free printing technique widely used to transfer different materials with high resolutions. It can deposit functional material without phase change to fabricate actuators, transducers, and other MEMS devices. In this work, LIFT is deployed to deposit NiTi shape memory alloy using CO2 laser (λ = 10.6 µm) in the form of the solid phase. The silicon wafer is used as the donor substrate since it is transparent to the CO2 laser wavelength, while the silica glass is used as an acceptor substrate. The donor substrate is coated with the Polydimethylsiloxane (PDMS) as a sacrificial layer that absorbs the laser energy and induces a thrust force for the transfer mechanism. Over the sacrificial layer, NiTi Shape memory alloy thin film is deposited with DC sputtering technique at working pressure 2 × 10–3 mbar and standoff distance 5 cm. After the donor preparation, the LIFT is deployed at various laser fluences and SOD to transfer NiTi on the silica glass substrate. The deposited geometry’s surface morphology has beenanalyzed using a scanning electron microscope (SEM) and optical microscope. The functionality of the deposited materials has been analyzed using Differential Scanning Calorimetry (DSC). © 2022, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.