Connected digital scales are Withings' historical products. The latest released, the Withings Body Scan, is an innovative product, both in terms of measurement and metrics, and in terms of design. It is positioned as a top-of-the-range product in the field of connected scales.From a mechanical point of view, this innovative design features a different structure from conventional digital scales, since it has no feet. This absence has led to the adoption of a so-called sandwich structure, with a rigid metal plate in the lower part of the scale to ensure correct weight measurement on softer floors (carpets or rugs, for example). This metal plate ensures good weighing performance on these soft floors, but makes the scale considerably heavier. In order to lighten the scale, a carbon-fiber composite stiffener was developed to replace the metal stiffener and reduce the weight of the scale. This development was carried out in partnership with Fairmat, a French start-up that develops composite parts from recycled materials.The development of the new stiffener has resulted in a part that can be easily integrated into the scale simply by replacing the old stiffener. The part has been designed to be produced on a large scale, in terms of manufacturing and cost, and to eventually replace the current stiffener. Functional tests carried out to date have shown that the scale with the new composite stiffener performs identically to the current scale. In terms of mass, the stiffener’s mass has been reduced by 38%, reducing the overall weight of the scale by 11%.In parallel with the development of this part, a numerical method has been developed to enable stiffener designs to be tested by FEM simulation, thus reducing development time and the need for preliminary testing and prototyping. Although this method needs to be refined and validated, it has shown very encouraging results on the composite stiffener example.