Researchers in the Netherlands have developed a simple method using kitchen cling film to reliably transfer large-area two-dimensional (2D) materials onto patterned surfaces, overcoming a long-standing obstacle in the field. The technique, developed by a team at the University of Amsterdam (UvA) and collaborating institutes, allows sheets roughly one millimeter in size to be picked up and placed with near-perfect success, a significant improvement over earlier probabilistic methods.
Since the isolation of graphene more than two decades ago, 2D materials have attracted intense interest for their unusual properties, including high electronic conductivity, mechanical strength, transparency, and flexibility. A persistent challenge, however, has been producing sheets large enough for practical use and transferring them onto other substrates without cracking or losing quality. The new work addresses this by using low-density polyethylene (LDPE), the same polymer found in common kitchen cling film, as a stamping medium.
Jorik van de Groep, who led the research at the UvA-Institute of Physics 2D Nanophotonics group, said the method enables, for the first time, the transfer of large 2D layers onto almost arbitrarily patterned surfaces. “Being able to do this is crucial since it enables the integration of 2D materials with structures like larger electronic devices and photonic coatings,” he said. “Most importantly, the transfer is no longer probabilistic but has a near-unity yield.”
Early work with 2D materials relied on mechanical exfoliation, using sticky tape to shave flakes from bulk crystals, a technique first demonstrated with graphene. More recently, gold-assisted exfoliation has produced high-quality, centimeter-sized layers of transition-metal dichalcogenides (TMDCs) and other materials, but transferring these onto structured surfaces remained difficult. For nanophotonics and device fabrication, researchers need to place 2D layers onto substrates that already contain electrical contacts, optical coatings, or other patterned features.
The Amsterdam team, which also includes scientists from the Van ‘t Hoff Institute for Molecular Sciences, ARCNL, and AMOLF, detailed its process in the journal ACS Nano. The researchers used a heat-resistant half-sphere covered with LDPE cling film as a stamp, mounted on a precision stage with force sensors. The stamp was moved slowly toward a monolayer of tungsten disulphide (WS₂) heated to 70 °C until contact was made. The system was then heated to 140 °C, causing the LDPE to melt and adhere strongly to the monolayer, before cooling back to 70 °C to solidify the polymer. Finally, the monolayer was pulled away and cleaned to remove residue.
Force sensors in the stage measured forces both in the plane of the 2D material and perpendicular to it, offering control and repeatability while providing insight into contact and friction dynamics. During initial contact, the normal force increased to 120 mN before the stamp was stopped.
To assess the impact of the transfer, the researchers imaged the monolayer before and after the procedure. Cracks covered 8% of the material before transfer, rising to 14% afterward, with new cracks mainly appearing at the edge of the stamp contact area. “As such, the procedure only modestly increases the cracked area fraction and largely preserves the monolayer topography,” van de Groep said. “More importantly, the material retains its good photoluminescence properties.”
The method could benefit scientists working on a range of devices. The team is already using it to develop atomically thin optical elements, optical modulators, single-photon emitters, and other optoelectronic devices. Van de Groep also noted the approach could enable fabrication of complex heterostructures relevant to quantum materials research.
Further optimization is underway, including the construction of a humidity-controlled enclosure around the stamping setup. Because 2D materials and the van-der-Waals adhesion between them depend strongly on surface chemistry and relative humidity, controlling the environment during stamping could improve the process further. The team is also developing additional methods to characterize the thickness of transferred layers.
