The design and construction of aerospace structures is governed by the concept of lightweight design to maximize sustainable loads while increase fuel-efficiency. Despite the use of materials with outstanding mechanical properties, such as aluminium alloys or fibre-reinforced polymers, the monitoring of these structures is of grave importance to ensure the integrity and furthermore the safety of the structure during its service life. Next-generation structural health monitoring systems themselves need to be lightweight and integrated into the structure to accomplish this task. The development of nanomaterial-based thin films with their unique properties made the design of inkjet-printed spatial strain sensors possible. However, the capabilities and qualities of such sensors is dependent on many factors including materials used and the ratio of components, utilized process for deposition of the material on the surface and post-processing procedure. The objective of this study was to develop a carbon nanotube (CNT) based thin film strain sensor and to optimize its electrical properties by enhancing its conductivity. To accomplish this task, the composition of the ink in which the CNTs are dispersed as well as the printing process were modified in comparison to a previous study where the thin film was sprayed onto the surface. The effects of these modifications were studied by microscopy to measure the distribution of CNTs. Additionally, resistance measurements were carried out for piezoresistivity characterization. Lastly, the MATLAB-based open-source software EIDORS was used to verify the electrical behaviour of the thin film sensor using a finite element approach.