Traditional sensor solutions are cumbersome. They contain environmentally harmful substances such as lead or rare earths, require costly maintenance and often cause hazardous waste due to batteries. The new sensors are based on lead-free aluminium nitride and use special metamaterials produced using 3D printing. These focus metamaterials bundle vibration energy, such as vibrations from rail or road traffic, exactly where it is needed on the sensor (“rainbow trapping”). This maximises the efficiency with which vibration energy is converted into electricity for the sensor
The result is a prototype just 300 micrometres long, i.e. smaller than a five-wheeler, which obtains its energy directly from the environment, works completely without a battery and transmits data wirelessly in real time.
From bridges to 6G stations
The potential applications are diverse. In structural monitoring, the sensors enable continuous, maintenance-free monitoring of bridges, tunnels and high-rise buildings, especially in places that were previously difficult to reach. They provide continuous data on material fatigue, vibrations or any damage and offer the possibility of equipping critical infrastructures with early warning systems. For example, to detect earthquake movements or damage to the terrain.
Another field is opening up with 6G technology. High-frequency, energy-autonomous microsensors will enable a very dense sensor network, which is essential for the next generation of digital communication. The new technology will become a key element for real smart cities.
Sustainability, ethics and regulatory added value
The elimination of lead and rare earths not only protects the environment. The innovation is also beneficial from a regulatory perspective, as no special disposal is required and global supply chains become more independent. The use of freely available materials also increases the economic feasibility and scalability of such solutions.
Interdisciplinary partnership and funding landscape
The technology is the result of a major collective research effort. From mathematical modelling at Imperial College, materials research in Zurich and Milan, through to industrial implementation by the project partners Multiwave and STMicroelectronics. The project was funded by the EU’s Horizon 2020 programme and the EIC Pathfinder, which specifically bridge the gap between basic research and concrete applications, bringing sustainable, microscale sensor technology to where it is most urgently needed – on buildings, in remote areas and in the network technology of the future. The combination of energy self-sufficiency, robust material selection and integrated digitalisation is exemplary for a construction and infrastructure sector that combines ecological transformation and technical innovation. The project thus provides a construction kit for an Internet of Things that works with the environment instead of against it. Pioneering and immediately applicable in practice
