Bernardo Dias was frustrated. As a PhD student studying ultrathin materials at the University of Amsterdam, he kept running into the same problem: every time he tried to move delicate atom-thin sheets onto a surface, they would crack into pieces too small to use. That changed when he reached into his kitchen for a roll of cling film. The stuff you wrap leftover pizza in turned out to be exactly what he needed.
Dias and his team just published their findings in the journal ACS Nano. Their discovery solves a tricky problem that has bothered scientists for over two decades. You see, some of the most exciting materials in modern science are now so thin they are literally just one atom thick. Scientists call these "2D materials," and they behave in strange and useful ways. Some conduct electricity with almost no resistance. Others interact strongly with light or flex without breaking. But here's the catch: working with something that thin is incredibly hard.
The old way to peel these layers off crystals involved pressing adhesive tape onto the material and peeling it away, similar to how you might accidentally strip paint when removing painter's tape. It works, but it cracks the material into flakes smaller than the width of a human hair. Far too small to build real devices.
In 2018, researchers found a better method using thin gold films, which let them peel off larger sheets about the size of a centimeter, roughly the width of your pinky finger. But there was still a problem: gold-assisted exfoliation only worked on perfectly flat surfaces. Most real devices have patterns, tiny electrical contacts, and textured surfaces. Cracking remained an issue.
That's where the kitchen cling film came in. Dias noticed something interesting when trying to replicate results from a Japanese research team. Kitchen cling film in Europe is made from a different type of polymer than what they used in Japan. The European version melts at about 120 degrees Celsius (248 degrees Fahrenheit), and that turned out to be the key. By gently heating the cling film, it would melt slightly and make the ultrathin material stick without breaking it.
"The discovery of using cling film for this application came by total accident," said Jorik van de Groep, who supervised Dias and leads the 2D Nanophotonics group at the university. "We observed that the polymer used here melts at 120°C, while theirs did not. This property turned out to be the defining factor in successful 2D material transfer."
The collaboration brought together scientists from multiple Amsterdam institutes, including chemists, nanolithography experts, and complex matter scientists working at Amsterdam Science Park. Their work opens the door to building much more powerful ultrathin electronics and optical devices.
"Encouraged by my supervisor, I went on a detour to find a better method, and it turned out cling wrap has just the right properties to handle these delicate materials gently and effectively," Dias said.