‘Sensor screw’ measures forces inside machines

Proving that the simplest ideas are often the best, researchers in Germany have come up with an innovative solution to make it easier to measure the forces that act between two components inside a machine.

The so-called 'sensor screw' is, as its name suggests, a screw with an integrated sensor. According to its developers at the Technischen Universität Darmstadt, the device enables users to control uncertainty in load-carrying mechanical systems, and gives them a 'sixth sense', as it were, when dealing with buildings and systems. The patented device can provide measurement data at certain points in time, as well as continuously, making precise quality controls possible. For example, if a piece of equipment that is deformed or whose thickness varies is being transported through a roll train, the sensor screws that hold the rollers would register it immediately. The researchers are also working to develop suitable analysis software so that this information can be relayed in real-time. "Until now, there were no good methods for attaching sensors" said inventor Matthias Brenneis. "Adhesive compounds dissolve easily, especially in a harsh real-world production environments. In addition, externally mounted sensors provide readings from 'outside', which means they could differ from the forces actually acting in the interior of a machine or a component." The advantages of combining a sensor and a machine component, says Brenneis, are obvious: "Screws are available practically everywhere and could be replaced by their 'sensing' counterparts in entire production chains. "What's more, their operation is very simple and the little 'measuring device' is hardly prone to faults. The sensor is located exactly where the forces are acting and therefore works very precisely, so that designing and dimensioning can be carried out more efficiently." The researchers developed the sensor screw over several years. They have now been awarded funding from the German government to take the device into mass production.