Nitinol (NiTi) is an interesting binary alloy which has applications in the medical, aerospace, automotive and energy industries exhibiting properties of superelasticity, shape memory, corrosion resistance, low stiffness, and good biocompatibility. Conventionally on a large scale, NiTi is manufactured via casting and drawing technique which is limited in producing complex shapes, and requires post machining, and specific dies for different geometries. Laser powder bed fusion (PBF-LB) is an emerging technology capable of producing nitinol components which are near-net-shaped, complex, and sustainable. In this thesis, numerical and experimental investigations are presented on NiTi for its applications in NiTi-based actuator systems. Commercial austenitic NiTi tubes were heat treated to achieve elevated austenite finish temperatures up to 27 oC and shape set to allow their usage as actuators. A full factorial design of experiment (DoE) was used to investigate the potential of austenitic, commercial NiTi tubes for actuation force as a function of time, and exposure temperature. A maximum force of 144 N was recorded during the actuation of NiTi tubes. Furthermore, NiTi tubes were manufactured via PBF-LB containing nickel and titanium atomic percentages similar to commercial tubes. The effect of heat treatment on tubes manufactured via both methodologies was investigated where Af temperatures were increased to 25.4 oC and 27 oC for PBF-LB tubes and conventionally drawn tubes respectively. A detailed numerical and experimental analysis was performed on austenitic NiTi lattice structures to investigate their mechanical loading behaviour under 7 % strain and energy absorption characteristics. Lastly, NiTi lattice structures were manufactured via the PBF-LB technique. Non-contact differential imaging correlation (DIC) was used to capture the mechanical strain behaviour of lattice structures and their energy absorption characteristics were measured. The numerical models implemented and analysed in ANSYS® were validated using the DIC-acquired experimental results of the stress-strain behaviour.