Smart Bolts
It is no secret that massive metal structures and structures such as bridges, wind turbines and scaffolding, bolted together, eventually "relax", which is fraught with serious consequences.
Scientists of the German Fraunhofer Cognitive Internet Technologies Cluster (a division of the Fraunhofer Society, the largest European association of applied research institutes — ed. Techcult) proposed to solve this problem by creating a smart device consisting of a bolt and a special washer. How does it work? A pressure sensor made of the thinnest piezoresistive film — DiaForce - is integrated into the washer. If the bolt is tightened to the stop, the film fixes the pressure value at three different points, but as soon as the bolt weakens, the electrical resistance of the film immediately changes, which, in turn, fixes the radio module at the top of the bolt.
Smart Bolts
Then the "alarm" signal encrypted by the module is transmitted to the nearest base station, whose staff has Internet access. Thanks to a special online portal, it is possible to constantly monitor all bolted connections of a particular object. The smart bolt's power source function is performed by a built-in thermoelectric generator operating on the temperature difference between the bolt head and the ambient air. In some cases, when there is a lot of sunlight around, it is possible for the system to operate from solar panels.