In the future, LEDs could serve as data transmitters and energy sources in holistic Internet of Things (IoT) networks. The University of Oulu’s professor Marcos Katz leads SUPERIOT, a Horizon Europe project that aims to develop a flexible IoT system based on the dual-mode use of optical and radio communications. The system will be sustainably powered by printed electronic components made from low-cost, bio-friendly materials. “The SUPERIOT project addresses a critical challenge for the 6G era: how to design IoT systems that meet the demanding performance requirements of future networks while remaining truly sustainable,” Katz said. “As IoT adoption accelerates, projections suggest that hundreds of billions of devices will be deployed globally. This scale raises urgent concerns about energy consumption, material use, and environmental impact.” The SUPERIOT project, led by professor Marcos Katz at the University of Oulu, aims to develop a truly sustainable and highly flexible internet of things (IoT) system based on the dual-mode use of optical and radio communications, combined with the exploitation of printed electronics technology. Courtesy of the University of Oulu. White LEDs are expected to provide approximately 95% of indoor lighting globally by 2035, and unlike conventional sources of light, they can be controlled easily. For these reasons, researchers are keen to explore ways to add additional functionality to the LED lighting infrastructure. “Developing light-based communication is rooted in sustainability,” Katz said. “We’re studying how existing infrastructure, like lighting, can be used in new ways.” Light-based data streams offer many advantages, in addition to energy efficiency. They are faster than radio communications, and more secure. Light communications can only be received by someone who is physically present in the same space as the source. “When the light source is in a closed room, there’s no way for anyone outside to tap into the signal,” Katz said. However, light-based communications also have limitations. A light source is not always available to send or receive information. And, efficient light communication requires a clear line of sight between the transmitter and receiver. “If a finger happens to block the smartphone’s light sensor, the connection weakens or cuts out entirely, prompting the device to fall back on radio waves,” Katz said. The SUPERIOT team envisions that light will complement radio technology rather than replace it. “Our goal is that, in the future, devices could switch flexibly between light and radio, depending on the environment,” Katz said. Katz sees many exciting possibilities for the future use of sustainable, printed electronics-based IoT combining optical and radio wireless technologies. In homes with visible light communication, LiFi, or “light fidelity” networks, could replace wireless Wi-Fi networks. A standard LED light could also function as a data router, sending information to a receiving device. “The LED lamp is modulated to flicker, and the receiver interprets the flicker,” Katz said. “When the light is on, the receiver reads a one; when it’s off, a zero.” A computer or smartphone decodes the light signals. The flickering is too fast for the human eye to see, so a person working remotely, for example, sees only a steady glow from the LED lamp when information is received by the home computer. Data transmission could occur in the reverse direction via infrared light, enabling everyday tasks such as sending an email. “It would be distracting if visible white light were emitted from a phone or computer,” Katz said. “Infrared light allows data to be sent discreetly.” The project team is developing light-based IoT systems for environments where radio signals can interfere with sensitive equipment, like the medical equipment used in hospitals or the gear used in aircraft. Unlike radio communication, light-based communication does not interfere with the radio signals that some apparatuses rely on to work properly. The team is also developing low-cost, printable electronics made with sustainable materials to use as IoT device components. Many devices, from smartphones to sensors, currently depend on components made with scarce materials. The printed electronics will be made from bio-based, renewable, abundant materials. “Our vision is to print complete IoT devices,” Katz said. “The finished product would be a sticker no larger than a bank card, designed to carry out its function seamlessly within the Internet of Things.” As part of an IoT network, a printed tag could, for example, track room temperature and automatically guide ventilation. A printed label could be placed on grocery items to update price changes in real time. In clinical settings, printed IoT devices could be used to track the location of equipment and staff and to monitor patients’ well-being in real time. Beyond data transfer, light could play an important role in smart cities of the future, where many devices will be able to collect data from their surroundings and transmit it autonomously. These devices could be powered by nearby LED lights, using tiny solar cells instead of batteries. “This could save a huge number of disposable batteries,” Katz said. “IoT devices that monitor the environment use so little energy that they can operate entirely on light from their surroundings.” The dual-mode, highly sustainable approach taken by the SUPERIOT team could result in a highly flexible, environment-friendly, low-cost communication system that can operate efficiently under changing conditions and in different scenarios. More information is available at the SUPERIOT website (https://superiot.eu/).