How many times have you wondered why radio antennas have to be rigid and bulky objects? The answer comes from a team of engineers at Columbia University who decided to completely rethink the concept of a radio antenna. Their approach is surprisingly low-tech: they took inspiration from the jacquard knitting technique, the same used for sweaters with Christmas decorations, to create flexible and portable communication devices.
An unexpected breakthrough in radio communications
Le radio antennas traditional are all around us, on the roofs of homes and in telecom facilities. They are essential devices but have always had obvious limitations: they are heavy, bulky and often expensive to produce. These constraints have been a significant obstacle for years, especially for those who live or work in remote areas where portability is essential.
A team of columbia engineering decided to approach this problem from a completely new perspective. Instead of looking for solutions in high technology, they turned to an ancient technique: float-jacquard knitwear, the same one used to create classic decorated sweaters.
The Magic of Smart Knitting for Radio Antenna
The process of creating these radio antennas textiles is as simple as it is ingenious. Using commercially available metallic and dielectric yarns, the team created their prototype. The technique involves using two or more types of yarn to produce a pattern, with one yarn “floating” beneath the fabric when not in use. This innovation is not just theoretical: Each metasurface with a footprint of approximately one square meter is knitted in just 45 minutes. And they are not delicate devices: they resist repeated washing and ironing, maintaining their properties unchanged.
Il Professor Nanfang Yu, a pioneer in research on nanophotonics devices, nostalgically recalled the purple sweater with white cats he wore as a child, noting how the same technique used for those decorations is now the basis of a revolutionary technology.
The float-jacquard knitting technique used to make these textile metasurfaces is exactly the same technique our grandparents used to make sweaters.
The future is in fabrics
The future prospects are exciting. The team is exploring techniques of knitwear modern (there are at least a dozen) to create more complex and multifunctional designs. The goal is to integrate electronic circuits and folding points into fabrics, creating devices that can be easily folded and unfolded or even switch between different electromagnetic functions.
Scalability is another strong point: commercial knitting machines can produce fabrics up to two meters wide, without limitations in length. This opens the way to the creation of radio antennas high-gain with apertures several meters in diameter, so light they can be carried by satellites to communicate across enormous distances.
It is important to emphasize that these devices were fabricated using commercially available yarns and exploiting established manufacturing techniques.
“Textile” Radio Antenna: A Bridge Between Tradition and Innovation
I like to think that this discovery is a perfect example of how innovation often hides in the most mundane aspects of our lives. Professor Yu suggested that knitting communities could find ingenious ways to integrate aesthetics and functionality into a sweater that can also act as a WiFi amplifier (assuming it’s safe for health).
The research, published in the journal Advanced materials (I link it to you here) demonstrates how sometimes the most elegant solutions to complex problems are found by looking back with fresh eyes. In an increasingly high-tech world, it is fascinating to see how an ancient technique can open up new frontiers in the communications of the future.
