This paper aims to simulate using Finite Element Modelling (FEM), a self-activating bistable buckled beam actuator using SMAs. In this work, various parameters such as the dimensions of the beam, shape geometry are studied to determine their effects on the deformation and buckling of the beam under a thermal load. The pre-sizing of the dimensions of the blade shows that the thickness and length of the blade have a minor effect on the maximum displacement of around 0.4 mm. By adapting the geometry to have variable thickness, the behaviour of the buckled beam was completely changed and was shown to be able to transition to another stable mode. The use of geometry optimization allows the division of the beam into segments that can be specifically actuated to improve self-switching. The central vertex of the beam was also able to be displaced by 2 mm. This SMA buckled beam system shows promise for use in compact micro-actuator systems.