Fraunhofer Institute for Integrated Systems and Device Technology IISBScreen-printed electrodes are equipped with a functional membrane that delivers sensitivity to chemical analytes in liquid specimen. The ion activity is converted into an electric signal, i.e. a ten-fold increase in concentration leads to a voltage change of roughly 60 mV. The conversion principle qualifies the sensors for facile and objective measurements and opens new applications like continuous monitoring of fluids.
Ion Selective Sensors
Examples
Nutrient analysis for precision farming
Precision farming
Potentiometric ion sensors are evaluated by simply reading a voltage between respective electrodes. In contrast to typically applied spectroscopic detection principles they do not need for transferring samples to a lab. When compared to test stripes, the electric measurement delivers an objective value and the sensor can be used multiple times instead of disposing it after single use.
Nitrate and ammonium sensors are utilized to detect the nutrient content of soil close to the roots of the plant. Together with the historical data and e.g. weather forecast the farmer can thus make a qualified decision on optimum nutrient dose and time and thus avoid over fertilization which is harmful to the environment.
Sweat sensor for sports application
Vital parameters from sweat electrolytes
Smart sensors in sports textiles offer an unobtrusive method for continuous monitoring of physiological parameters during exercise. The electrolyte sensor targets monitoring of ammonia levels in sweat. Real time analysis without need for hindering or even invasive sample collection is a clear advantage over blood analysis.
Ammonia and ammonium in blood are mostly a result of metabolic degradation of proteins during muscular overstrain. Ammonia molecules are permeable through cell membrane and further on get easily transported from blood to sweat. During physical strain the content of ammonia in sweat is in the range of millimols, which is orders of magnitude higher than in normal condition.