Global warming has become a worldwide issue. Carbon dioxide (CO₂) is not only a cause of global warming; it impacts our health greatly. To help improve the air quality in homes, offices and hospitals, there is a growing need for sensors that detect CO₂ and other gases. TDK has successfully developed a CO₂ sensor dramatically smaller than conventional ones.
The Rising Importance of CO₂ Sensing
Have you ever struggled to keep focused or felt sleepy after spending a long period of time in a room with inadequate ventilation? The culprit may be CO₂. Because high CO₂ concentration in a room is known to trigger various effects on the human body like headaches, drowsiness and fatigue, CO₂ concentration is often used as an indicator to evaluate air pollution. Today, in-room CO₂ concentration is increasingly being used as a bellwether for ventilation in order to mitigate the spread of coronavirus infections. Furthermore, in an effort to counter global warming, there is a growing need for equipment that can detect the amount of CO₂ emitted from factories, industrial equipment and automobiles. From personal health to global issues, CO₂ sensing is taking on a more crucial role.
Issues with Conventional CO₂ Sensing
Despite the growing needs to measure CO₂ and other chemical substances in the air, CO₂ sensors to date have faced many technical challenges. Conventional gas sensors employ optical techniques to measure the amount of molecules present in a gas, which not only necessitates bulkier packages, they also tend to be power-hungry and costly, limiting the types of equipment that can be fitted with them. While sensors that take an eCO₂ (carbon dioxide equivalent)*1 approach do have the advantages of smaller size and lower power consumption, they measure substances equivalent to CO₂ instead of CO₂ directly, compromising accuracy.
Developing a Microminiature, Ultra-Low Power CO₂ Sensor
Senior Director, Emerging Business InvenSense
By combining novel materials development, MEMS process technologies, and AI and machine learning capabilities, TDK Group company InvenSense has defied past challenges and created the TCE-11101, a miniaturized gas sensor platform capable of directly and accurately detecting CO₂. The TCE-11101 is part of the SmartEnviro™ family of environmental sensors, housed in a miniscule 5 mm x 5 mm x 1 mm package, making it suitable for even mobile devices. It is capable of detecting CO₂ across a very wide, 400 ppm to 50,000 ppm range, while consuming less than 1 mW of power.
Dr. Sreeni D. Rao, Senior Director, Emerging Business at InvenSense, who was in charge of the development, explains: “The TCE-11101 enables not only IoT consumer solutions, but a wide range of health and commercial applications such as leakage detection. It is easy to program and integrate into a system, facilitating final system design and deployment by the customer.” The general availability of TCE-11101 is planned for the second half of 2021.
A Tiny CO₂ Sensor Opens Huge Application Possibilities
Because TDK’s CO₂ sensors are smaller and consume less power compared to conventional sensors, they can be installed in devices where it was simply impossible in the past. These include mobile monitors for measuring the air quality of a room effortlessly, as well as in-vehicle monitors that support safety during long-distance driving. It is also ideal for smart buildings and homes, allowing granular control of heating, ventilation, and air conditioning (HVAC) systems based on CO₂ concentrations.
Dr. Rao also emphasizes the need for gas sensors other than for CO₂. “The air we breathe is composed of many gases besides CO₂. Ozone, carbon monoxide, nitrous oxide, sulfur compounds, methane, acetone, formaldehyde, etc. can all be harmful to human health, so there is a great need to monitor them.”
Systems that control air conditioning according to temperature and humidity are now commonplace. As CO₂ and other gas sensors evolve, more advanced monitoring of the air environment will become possible in the future, which is expected contribute to maintaining the health and well-being of more people.
- eCO₂: Carbon dioxide equivalent. Sensors based on eCO₂ suffer from inaccurate measurements of CO₂.
- MEMS: Micro-electro-mechanical systems. Microscopic devices that integrate electrical circuits and mechanical components. They enable more compact products that consume less power.