When screws “think for themselves”

© Fraunhofer IIS
The “smart screw connection” is a fully integrated IoT device with self-powered wireless data transmission.

Smart screws increase the safety of bridges and scaffolds


Another IoT-COMMs project is about developing a smart screw connection. It enables wireless and self-powered monitoring of connections on safety-relevant structures such as bridges and scaffolds – without any need for additional infrastructure. A system of sensors uses variations in electrical resistance to measure the preload force on the screw connection and uses the pressure difference to determine whether the screw has loosened. The load data gathered by the sensors is transmitted via the mioty® wireless protocol, with the data transfer from each screw configured and encrypted separately.

Integrating energy harvesting into the mioty® LPWAN technology developed by Fraunhofer IIS paves the way for a self-powered system capable of collecting and transmitting sensor data reliably. The energy required for transmitting the sensor data can be harvested from minor vibrations and minimal shifts in temperature.