Fraunhofer Institute for Physical Measurement Techniques IPM
The traceability of food products or sensitive goods such as pharmaceuticals is becoming increasingly important in times of globalized markets. With modern technology, production and logistics in the food industry can be controlled, documented and monitored efficiently and seamlessly. Here, sensors play an important role since they provide information on a variety of environmental parameters during the production or transport of food. Fraunhofer IPM develops special sensor technology for food monitoring.
Wireless sensor technology
RFID tags equipped with sensors are intelligent companions for goods, enabling seamless monitoring of parameters such as temperature, humidity, light or the concentration of certain gases. In the case of non-compliance with standardized transport conditions, logisticians can actively intervene in the supply chain using GPS positioning. In the event of damage, logging the measured values at any time during transport helps to determine the cause.
Fraunhofer IPM develops small, lightweight and flexible temperature, humidity, light and gas sensors, which can be integrated into the thin and flexible substrate of adhesive labels. Communication and data transfer with the sensor system is wireless, for example using RFID (Radio Frequency Identification). The RFID tags are semi-active UHF or HF RFID tags (868 MHz or 13.56 MHz).
Color change based gas sensors, which we also develop at the institute, already react at room temperature. These colorimetric gas sensors are integrated on an RFID label and function on the principle of color change materials such as pH indicators. The commonly used metal oxide semiconductor sensors for gas detection operate at temperatures above 350 °C and can thus not be used in combination with RFID technology. The high operating temperatures require too much energy and would cause the plastic labels to melt.
ATR spectroscopy
Production control in the beverage industry has a strong economic interest in the online monitoring of various process parameters, such as the concentration of dissolved carbon dioxide, alcohol and sugar content. Fraunhofer IPM develops optical sensors for the parallel determination of CO2, alcohol and sugar. At the core of these sensors is an infrared-optical measuring method based on attenuated total reflection in combination with miniaturized, spectrally tunable infrared sensors.