Challenge

A vacuum is more or less ubiquitous; you encounter it when vacuuming or when drinking with a straw. In engineering, it is defined as a volume in which the pressure is significantly lower than atmospheric pressure.  But measuring a vacuum precisely is not at all easy, and moreover, not all vacuums are created equal. An absolute pressure of 0.001 to 1 millibar is referred to as a fine vacuum, but if the pressure is lower – up to 10-7 millibars – then it is a high vacuum. The high vacuum is required in various processes from metal industry to medical technology. Although the measurement of pressure has long been state of the art, thermal vacuum sensors currently have to be combined with other sensors to form a complete system in order to cover the entire measurement range. For the high vacuum range, ionization sensors are usually used for this purpose, but they are expensive.

Goals and procedure

In the NEOVAK project, the research partners want to record the vacuum range from 10-6 millibars to atmospheric pressure with a single thermal sensor element and only one measuring principle. At the same time, the new system is to be reproducible, stable, and insensitive to external influences such as temperature. For the industry, this is something of a small revolution, as it will considerably reduce the technical and thus also the financial effort required for the measurements. To achieve the project goal, miniaturized sensor elements are being developed and combined with dynamic measurement methods – the so-called “3ω” method. Once the most suitable materials and components have been found and an optimized design has been created, experiments will be carried out on miniaturized thermal sensor elements and a vacuum sensor that is based on these elements. Finally, the functionality of the measurement principle will be demonstrated on gas and inertial sensor demonstrators.

Innovations and perspectives

Sensor technology is a key technology for Germany as an industrial location and a growth market. Since 2010, the global market for sensors has doubled to currently around 200 billion US dollars. Especially for Regensburg with its highly innovative environment of medium-sized companies, sensor technology has a high significance that is also expressed by settling the state cluster on sensor technology there. The simpler and less expensive solution envisaged in this project makes a significant contribution to strengthening competitiveness, as the sensor elements lead to completely new applications and sales markets. Despite their simple and compact design, the sensors have high sensitivities and short response times. This might also be very interesting for hydrogen detection in fuel cell vehicles, for example. The approaches researched in NEOVAK will thus lead to further exciting follow-up projects for applications in position and motion sensor technology.