Sensor nose for dangerous gases
Modern sensor technology enables the detection of gaseous, toxic substances. Especially in safety-critical working environments, the sensors act as warning devices by sounding the alarm when the concentration of hazardous substances is too high – e.g. as a result of leaking gas systems.
State of the art
As a rule, the sensors are adapted to the substance they are supposed to detect with the aid of a specific coating, so that common analytical devices only allow the detection of a single substance. If the target substance accumulates on this layer, a chemical reaction is triggered, which also causes the electrical conductance of the sensor to change. The course of the changes in conductance enables conclusions to be drawn about the concentration of the substance, whereby in most cases only an exceeding of the limit value is detected.
These restrictions have now been lifted by scientists of the Institute for Automation and Applied Informatics (IAI) at KIT in cooperation with a working group of the Institute for Sensor and Information Systems (ISIS) at Karlsruhe University of Applied Sciences. They produce sensor arrays on microchips whose single elements are coated differently. In addition, the sensors are heated in order to achieve the corresponding reaction of the target substances on the sensor surface at an optimal temperature. Over time, characteristic conductivity changes, so-called conductivity time profiles, result for each target substance, with which the substances contained in the substance mixture can be unambiguously classified. Before it is used for measurement, the sensor is calibrated according to the target substances that are to be detected. If a target substance is detected, the concentration of the target substance and its development is continuously analysed and limit value violations can be displayed. In addition to stationary analysis, mobile use in battery operation is also possible. Furthermore, the source of the substance can be localised with a network of sensors.
The newly developed sensor arrays, which can be produced cost-effectively, cover a wide range of different substances – supported by the thermocyclic operating process. Due to the preceding calibration to a specific target substance, the necessary computing power for the evaluation can be minimized.
Options for companies
KIT is looking for partners to implement a prototype up to the stage of integrating the novel sensors in an analytical device.
Your contact person for this offer
Innovation Manager Karlsruhe Institute of Technology (KIT)
Innovation and Relations Management (IRM) Phone: +49 721 608-25587