The integration of sensor technology is becoming increasingly important in the era of Industry 4.0 and poses challenges for design engineers, particularly in the case of limited installation space. Therefore, various approaches are being researched to integrate sensor functions into machine elements. 

The rolling bearing has emerged as the preferred source of process data for parameterizing digital twins in order to obtain high-quality data with comparatively little effort. For example, conclusions can be drawn about the operating condition of thebearingby measuring the electrical properties (Fig.7). Since the lubricant film thickness and the deformation in the contact depend on the load, the electrical properties of the rolling element raceway contact change measurably as a function of the load. The determined load data can be used, for example, for process monitoring or incorporated into a real-time service life model that enables improved estimation of the remaining life span. In addition, a statement can be made about the lubricant condition, which exhibits altered electrical properties as aging progresses. Further research and subsequent market introduction of these approaches have the potential to make the benefits of Industry 4.0 easier and more cost-effective to harness. Desig engineers can resort to a familiar catalog of machine elements and at the same time integrate additional sensor functions into the product.