The market for sensor related applications and products are growing. An example of such a product is a detector system for measurement of carbon dioxide in air. Within the consumer market one example were these systems are used is as safety switch in kerosene heaters.
Development of products for the consumer market and the low-cost segment involves major challenges for the researchers. The low-cost must be achieved at maintained functionality, performance and security.
For several years Mid Sweden University has been working in close relation with a manufacturer of systems that measures the concentrations of carbon dioxide levels air. The system is based on an indirect gas measurement that uses the property of infrared light absorption in the gas in proportion to its concentration. By illuminating a gas atmosphere with infrared radiation and then allowing an infrared sensor to register the amount of the radiation passing the gas atmosphere, the gas concentration determined. This method is known as the Non dispersive infrared technology. In a kerosene heater application, this system is possible to use as an alarm that is triggered if the carbon dioxide level rises and becomes too high. The type of infrared sensor that is used in this system is also used in ear thermometers, which is also a major commercial market.
The research project ProSpekt consists of the development and manufacturing of cost effective infrared sensors for applications in the 4µm wavelength range. The goal of this project is to examine three types of infrared absorption layers in order to improve the sensitivity of the sensor. The scientists has previously developed a thermopile sensor including a temperature-insulated polymer membrane. By making the detector more sensitive, it would be more attractive in a commercial market.
The researchers are now looking at a part of the project which involves integration of the infrared absorber into the detector membrane. This would allow higher process control and better sensitivity to the detector. Another part of the project is to study the semiconductor lead selenide as infrared absorber. Lead selenide is directly sensitive to light in the MWIR infrared region and could thus provide a simple absorption structure. The project will run until September 2013.