This invention relates to a novel wireless barcode MEMS canary which can be embedded in electronic systems and periodically monitored to measure degradation over a period of time. The material used to print the bars of the barcode is selected such that it is capable of changing one or more of its properties in response to a change in ambient conditions. Means are provided for reading out said change in properties such that when an interrogator is brought into proximity to the sensor, the change in properties can be detected. By establishing the relationship between the healthy state of the barcode and its degradation to that of the electronic system and the components, the residual life of the system can be established and preventive measures taken before failure.