When engineers want to know how much stress mechanical components such as wind turbine blades or machine parts are subjected to, they usually do so via a series of sensors. These sensors are typically either built into components, or are glued onto them. A new polymer-metal composite material developed at Germany’s Fraunhofer Institute for Manufacturing Technology and Applied Material Research (IFAM), however, may be about to change that – components made from the material are reportedly able to act as their own sensors.

The electrical resistance of the substance changes as it is subjected to tensile or pressure loads, and these changes are sent as signals through cables to a measuring instrument.

The polymer-metal composite can be made with a wide variety of plastics, and is easily processed using conventional machines such as extruders and injection molders – this means it can be custom-made for specific applications. It can also be laminated into large mats, and in the future could be sprayed onto geometrically complex surfaces.

Developers also claim that it is lightweight, and is a very good conductor of both heat and electricity. Its conductivity can be tweaked by varying the amount of metal it contains, which can be as much as 90 percent by weight.

IFAM is now looking for industry partners to try out the composite, which will be unveiled at the ELECTRONICA 2010 fair in Munich, from November 9 - 12, 2010.