World's smallest impedance spectroscopy system

The larger an industrial machine, the more difficult it is to detect an unwanted deviation in oil pressure or even a leak in a line from the outside in the event of a malfunction. A lot of time often elapses before the needle in the haystack is found by specialist personnel. This results in production losses and high costs. The situation is similar when it comes to identifying the causes of illness in humans. If patients complain of pain in the abdomen, there is usually no way around a complex gastroscopy or colonoscopy. In such cases, electrochemical impedance spectroscopy can help.

In this procedure, a frequency spectrum is sent from one electrode through a medium to a second electrode: From this, a spectrum, i.e. a specific fingerprint of this medium, can be derived. If changes in material or fluid properties become apparent, this can be an indication of either the progressive corrosion of a component or the presence of a certain disease. Until now, impedance analyzers have not been small and mobile enough to be used for these purposes. Researchers at the Fraunhofer Institute for Reliability and Microintegration IZM in Berlin, with support from MST and Sensry, have therefore developed a compact and modular IoT sensor for these applications that can measure impedances and transmit them wirelessly. Consequently, it is not only waterproof but also biomedically compatible.

The sensor is made of a biocompatible polymer and combines the two necessary electrodes with numerous components for analyzing environmental properties, including six sensors for measuring a wide variety of data, in a space measuring just 11 x 16 square millimeters. In addition to temperature, pressure, humidity and sound in the environment, the small multi-talent can also record its own acceleration behavior, rotation or ambient noise. Light and colors can be determined by an integrated light sensor.