What specifically about the sensors allows them to stay in concrete for 80 years?

The sensors are very robust and do not contain active electronics. The electronics embedded in the sensors are optimally protected by a thick surrounding layer of epoxy resin, ensuring that external influences such as moisture, stress, etc., do not damage the sensor. The statement about the sensors having a very high lifespan is also based on the principle of energy transfer via RFID. This means there are no cable connections or similar components that can become porous over time and weaken the concrete structure. The lifespan has been demonstrated through MTF calculations by the Fraunhofer Institute. Due to the components used, the probability of failure and the durability of the product were examined, resulting in a calculated lifespan of over 200 years. Since we adopt a realistic approach, we guarantee a lifespan of more than 80 years, analogous to the calculated service life of a concrete structure.