InterFlex targets the development and standardisation of interconnects within flexible foil systems: On-foil connections of different components on a single substrate foil and interconnection of several functional foils into a foil system. The integration technologies required, when building a flexible foil system, i.e. homogeneous integration of electrical components on foils, heterogeneous Si IC-to-foil and foil-to-foil integration will be developed. This includes handling and alignment of silicon or foil based components on foil, electrical contacting, mechanical stabilisation, mechanical and electrical contacting via one-step lamination processes, as well as developing interconnection technology by vias. Reliability investigations will prevent failure mechanisms of flexible foil systems and their interconnections.The interconnection technologies will be applied in the realisation of a flexible, energy-autonomous system for environmental sensing with radio frequency communication capabilities. A combination of flexible amorphous silicon, photovoltaics and thin film foil battery provides the energy for driving sensors (temperature, dew point, humidity, CO2 concentration) and reading out their signals as well as driving the transmission of the sensor output to an external base station via a UHF radio frequency link at 868 MHz.The consortium of InterFlex consists of European industrial giants Bosch and ST Microelectronics who combine their expertise on packaging and flexible foil systems. Their expertise in complemented by Henkel Belgium in the materials field and by Infotech in the automation field, as well as leading applied research organisations CEA and Fraunhofer with background in flexible components and systems.