NoMADE : collaborative project financed by Bpifrance and Région Pays de Loire, led by DOREL (a world class juvenile products company) which the purpose is to design a new concept of child seat by increasing its degree of mobility and by improving its characteristics such as weight, dimensions and adaptability to different kinds of transportations. Topological optimization, based on the crash equivalent static load, are included in the first step of the design phase to define the main structural components of the car seat which must satisfy crash-test situation. The possible shapes of the components are dependent on the constitutive material and the associated manufacturing constraints.