For advanced body related applications, there is a need of soft, conformable, elastic, mechanical compliant and washable systems. Smart clothes for health monitoring, sport or professional protection need washable and conformable electronic systems, which can be deformed up to 20%. Implants, like monitoring sensors, or functional implants, need softness, stretchability to comply with the human body, chemical resistance, and biocompatibility. Many technologies are already available, like polyimide or PET/PEN based flexible electronic system, or conductive yarns for textile which can be knitted or embroidered to produce textrodes or textile based electronic systems. However softness and interconnections are still problems. Polymers based electronic system or stretchable electronic systems are a possible solution. We have developed several technologies to produce stretchable electronics systems. They are based on the concept of flexible functional islands, onto which standard SMD components are soldered, interconnected with meanders shaped metallic stretchable interconnections. Metallic interconnections are made from copper or gold and are optimized using FEM analysis. Stretchable electronic systems are then molded in elastomeric (e.g. silicone rubber or polyurethane) matrix. They can sustain at least 100% of elongation and 3000 cycles at 20% of elongation. They can be integrated in textile and they are biocompatible and washable.