Two sheets of carbon. Twist one by 1.1°.

After two decades, the score is clear if you look at what people can buy. 2D materials ship today as additives and films: graphene in composites, coatings, tyres and concrete, graphite-family heat spreaders in phones, conductive additives in battery electrodes, and a few electronic devices, most convincingly graphene magnetic sensors. What did not happen is the version that got the headlines. There is no graphene battery that stores more charge, no mainstream graphene touchscreen, no graphene processor, and graphene has been called a wonder material for twenty years while remaining absent from your laptop. The reasons are consistent across every application: making a perfect small flake is easy and making a merely adequate large one is not, contacting something one atom thick is hard, and incumbent materials are cheap and keep improving.

The credible case for the next decade is narrower and more interesting than the original pitch: 2D semiconductors as a channel material in advanced chips somewhere in the 2030s, because the semiconductor industry has no obvious alternative when silicon stops thinning; niche sensors and medical devices where being all-surface is decisive; and continued unglamorous growth in composites and thermal films. The strongest thing that can be said in the field’s favour is that the industrial research is now being done by chipmakers rather than by enthusiasts, which is usually the sign that a material has stopped being a story and started being an engineering problem. Whether that ends in products is not yet decided, and anyone who tells you otherwise is selling something.