Basements, tunnels, and interior of large buildings often become communication "blind spots" due to wireless signal obstruction. Now, a research team from Aalto University in Finland has developed a new type of intelligent panel called "Metacrystal" that can be manufactured through 3D printing. Without the need for power and electronic components, it can guide radio waves to propagate around obstacles like a mirror reflecting light, providing a new solution for low-cost expansion of coverage in future 6G networks. The relevant results were published in the latest issue of the journal Nature Communications.
With the development of 6G communication towards higher frequency bands, network bandwidth will significantly increase, but high-frequency signals are easily obstructed by walls, human bodies, and other obstacles. The current solution to signal coverage problems usually relies on adding devices such as routers, repeaters, and base stations, which not only have high construction and maintenance costs, but also increase energy consumption.
The meta crystal developed by the research team this time is a passive intelligent panel manufactured through 3D printing. The first author of the paper, Mahdi Asgari, compared it to a "mirror" of radio waves. He explained that when the room lacks light, people can either add more lighting fixtures or use mirrors to direct existing light to the areas that need illumination. The function of a meta crystal is similar, as it does not generate new wireless signals, but rather redirects existing signals to areas that were previously difficult to cover.
These panels can be installed on surfaces such as walls, ceilings, furniture, etc., guiding signals to building corners, obstructed areas, and even directing transmission to specific users or devices, thereby improving wireless network coverage.
Unlike many existing intelligent surfaces that can only perform a single task for a single directional signal, the meta crystal adopts a three-dimensional structural design that can simultaneously process multiple incident signals and operate in multiple frequency bands. In addition to reflecting and transmitting signals, it can also absorb unwanted signals, thereby reducing wireless interference.
The research team stated that traditional reconfigurable intelligent surfaces often require a large number of adjustable units and complex control circuits, which are costly and difficult to deploy widely. The meta crystal panel can be directly manufactured using 3D printing, with an estimated material cost of only a few tens of euros per panel, and can be customized according to specific application scenarios. This technology is particularly suitable for environments with relatively fixed layouts such as factories, warehouses, indoor 5G/6G networks, and long corridors. In these places, passive panels are expected to achieve wireless signal optimization at a lower cost.
At present, the research team is promoting the commercialization of this technology and exploring a new generation of reconfigurable meta crystal panels that can automatically adjust performance according to environmental changes, hoping to apply this intelligent wireless device to indoor spaces and urban outdoor scenes in the future. (Looking into the New Era)