Today a need is emerging for embedding electronic and sensor functions in the products which needs these functions, and, importantly, to do this without noticeably influencing the mechanical design of the product. This contribution describes an approach used to produce a 2.5/3D free-form rigid and smart objects or randomly shaped circuit. The proposed fabrication process of shaped circuit is compatible with a typical printed circuit manufacturing and electronics assembly. Once the circuit is completed in its flat shape, its random final functional shape is given using thermoforming. In order to be able to deform a given flat circuit to its final form with predictable final spatial positions of components and interconnections. a FEM simulation is conducted to model the thermoforming of polymer based electronic circuits. As one of the process outputs, the wall thickness distribution predicted for the final part is compared with the experimental results . Keywords--- 2.5/3D circuit, Thermoforming, Numerical simulation, Hyperelastic . 2Centre for Microsystems Technology, imec and Ghent University, Technology Park 914, B-9052 Ghent, Belgium, 3KACST-Intel Consortium Center of Excellence in Nano-manufacturing Applications (CENA), Riyadh.