Three researchers from the Institute of Microsystems Engineering (IMTEK) at the University of Freiburg want to develop sensors based on Surface Acoustic Waves (SAW) technology for the smart home sector. The wire-less and battery-less sensors are intended to replace previously available battery-operated products and thus be more resource-saving and environmentally friendly than current solutions.
Surface acoustic waves are sound waves that propagate flat on a surface in two dimensions. The propagation speed of such waves depends on the mechanical deformation of the material, temperature and deposits on the surface. With the aid of these various dependencies, SAW sensors can accurately measure chemical and physical variables, so that they can be used, for example, to determine temperature and pressure. To read out the data, the wireless sensors are in radio communication with a reader via an antenna.
“So far, SAW sensors have not been used in the smart home sector because the sensors do not have a strong enough range to be readable over the required distance and the readers are too expensive,” says Christian Ortolf. However, due to their battery-free power supply and their long service life, SAW sensors are more environmentally friendly and more convenient to use than existing products. To make use of the sensors, the team will also develop cheaper SAW readers that will serve as a bridge to the regular smart home system. For example, the sensors can inform smart home users via mobile phone messages whether a window is still open when they leave the house and the heating is therefore heating up unnecessarily.
The team is assisted in the development of the sensors by the physics simulation software DESMA. “The software allows us to reduce the design process of SAW components from many months to a few weeks, which is why we already have requests to co-design with other companies,” Ortolf says. As a prelude, a sensor is to be developed that registers the opening of windows and doors. In the long term, however, the founding team would also like to position itself in the smart home market and industry with other battery-free products.
The researchers Dr. Christian Ortolf, Taimur Aftab and Sergio Gutierrez from the Institute of Microsystems Engineering (IMTEK) at the University of Freiburg would like to develop sensors based on Surface Acoustic Waves (SAW) technology for the smart home sector. The team is supported in founding their start-up “SenSAWtious” by Prof. Dr. Leonhard Reindl, the former holder of the professorship for Electrical Measurement and Test Methods at the IMTEK and by Prof. Dr. Stefan J. Rupitsch, the new holder of the professorship for Electrical Measurement and Embedded Systems, also at the IMTEK.
