IoT Integration of Sensors and Their Application to Environmental Measurement
The Internet of Things (IoT) is gaining attention as one of the next-generation technological revolutions, and sensors are one type of device that connects to the internet to provide useful data. There are various types of sensors, such as physical, chemical, and mechanical sensors. A signal processing circuit is what drives these sensors and converts their output into a voltage value that can be read by a microcomputer. Understanding the principles of sensors requires knowledge of physics, chemistry, electronics, and mechanics. Manufacturing them requires microfabrication and integrated circuit technology, and using them effectively requires knowledge of electronic circuits, microcomputers, and programming. The fusion of multiple technologies is what makes this field interesting, and I have been involved in sensor-related research since my undergraduate years. The targets of measurement are wide-ranging, including engineering, biology, agriculture, and oceanography. To understand the meaning of the data, one needs not only statistical and analytical techniques but also an understanding of the needs of the field where the sensors are used. The recent research trends in IoT, which require the fusion of multiple fields, remind me of the excitement of the 1990s when individuals began using personal computers.
While terms like "data-driven society" and "social big data" exist, we are entering an era where individuals can easily create devices to measure the data they want, share it over the internet, and provide feedback where it's needed. Environmental measurement is one area where this approach is particularly useful. Since the accident at the Fukushima Daiichi Nuclear Power Plant, I have been conducting research on devices that allow citizens to easily measure and share radiation data. Recently, I have expanded the scope of measurement to include PM2.5, slope and landslide information, odors, and water quality. Of course, this data is also measured by government agencies and the Japan Meteorological Agency, but by enabling citizens and farmers to measure data at more granular locations, I believe we can contribute to disaster prevention and improve the safety and productivity of agricultural products. In particular, to create devices that can be used outdoors in places like farmland and disaster sites, we are working in collaboration with companies to develop devices that can be powered by solar cells, combined with Wi-Fi or smartphones, and can be set up and running in about 15 minutes (Figure 1).
One might think that such devices are expensive and difficult for a university to create, but there is a movement of "Makers" and "Hackathons" where individuals build and present their own devices. Thanks to information sharing on the web and elsewhere, even high school students, if motivated, can now build their own devices and share them on the internet. In our laboratory, we are also developing environmental measurement devices that turn existing smartphones into measuring instruments by connecting sensors to them and using their communication functions to share data over the internet (Figure 2).
I hope that our laboratory will nurture individuals who can freely master the wide range of knowledge required in the IoT era, and that they will become leaders in the next generation, bringing happiness to society.
Figure 1. A conceptual diagram and prototype example of environmental measurement using small solar cells and Wi-Fi-connected sensor modules. A wider area can be covered by using sensor networks or cellular networks.
Figure 2. A module and measurement software that can be connected to a smartphone or tablet to measure radiation. It is possible to measure while capturing location information using the GPS function.