Lattice metamaterials, which consist of a combination of air and solid, exhibit favourable characteristics due to their significantly reduced weight in comparison to conventional bulk materials. With advancements in additive manufacturing techniques, the fabrication of these metamaterials in intricate geometries and diverse configurations has become achievable. A recent approach to broaden the range of design possibilities for these materials involves the use of multi-material additive manufacturing technology. This thesis investigates the elastic and inelastic mechanical properties of multi-material lattice structures through analytical, experimental, and finite element analyses. The objective is to comprehensively understand how the presence of different materials in various regions of a lattice material can impact its overall behaviour. The research aims to contribute to the development of high-performance, lightweight materials capable of adapting to environmental stimuli. To this end, 2D and 3D multi-material lattices were designed and fabricated using Polyjet 3D printing technology. The fabricated samples underwent a range of thermo-mechanical tests. First, various analytical models were developed for predicting the elastic behaviour of the lattices in order to investigate the impact of material variation and relative density. Subsequently, in order to understand the mechanical characteristics of the manufactured multi-material lattices beyond the elastic range, several thermo-mechanical studies were conducted. The studies examined how the temperature and strain rate dependence of individual materials affects the overall behaviour of the lattice in both the elastic and post-elastic domains. Ultimately, based on the previous thermo-mechanical investigations and in order to actively manipulate the mechanical characteristics of the structures, a cost-efficient conductive coating was developed and utilised on the polymeric lattice. The application of the coating allowed for precise adjustment of the mechanical properties of the multi-material lattice structures through Joule heating, hence facilitating the development of high-performance metamaterials with enhanced functionality and adaptability.