Researchers at the Bilkent University Nanotechnology Research Center (NANOTAM) are working to develop sensors that will give refrigerators an “electronic nose” to detect food spoilage. The project is funded through the SANTEZ program of the Ministry of Industry and Technology.
Consumers often complain about the bad smell in their refrigerators. What they usually do not know is that the smell is due to microbial food spoilage. It originates from chemical gases generated by the biological activities of the bacteria in food products. If a way can be found to detect these gases earlier than a human nose can, the food can be consumed or discarded well before it becomes a danger to health or contaminates other food stored in the refrigerator.
An electronic nose for refrigerators would recognize the volatile organic compounds (VOCs) that come out of bacterial activities at an early stage, well before food spoils. NANOTAM researchers are working to develop a low-cost, energy-efficient smart system with a highly sensitive sensor to detect VOCs. The system is intended for use in commercial refrigerators.
Project researchers M. Deniz Çalışkan and M. Cihan Çakır explain that the sensors are based on micro/nanotechnologies. The active materials that recognize the VOCs are nano-structured metal oxides. The platforms that serve as micro-hotplates for the active material must be heated up to 300-400oC in tens of milliseconds to recognize VOCs. These micro-hotplates are produced using MEMS-based micro/nanofabrication processing technologies, including nanofilm deposition, dry and wet etching, thermal oxidation and nanolithography.
The SANTEZ program under which the project is funded promotes industry-university collaboration in research ventures oriented toward product development. The director of NANOTAM, Prof. Ekmel Özbay, who is also the principal investigator of this new project, states that the use of this kind of nanosensor in refrigerators will be a significant contribution to public health. Moreover, the applications of the research are not limited to refrigerators, since these sensors can also be used in cars and air-conditioning systems.