Materials lie at the heart of our century’s major challenges: rapid urbanisation, rising living standards, supply pressures and environmental imperatives. In this issue we show how there are solutions for all this, and that these solutions combine performance, sustainability AND competitiveness.

Materials have always been essential to human life, whether for food, clothing, heating, healthcare, defence, transport or communication. Yet up until the first COP in Rio in 1992, people mainly chose products based on their price, without giving much thought to the materials they were made from, let alone where those materials were sourced, processed and transported. And it was only during the COVID-19 pandemic that we truly realised that it is no longer enough simply to meet the global population’s basic needs for food and shelter. We must also ensure a steady supply of materials for an urban population and a rapidly growing middle class. By 2050, 68% of the world’s population will live in cities (compared to 33% in 1960), and the middle class is expected to account for 65% of the population by 2030 (compared to 15% in 1960). We therefore need materials to provide high-rise housing, packaged food, household appliances, medicines, computers, mobile phones, cars, public transport and tourist travel.

In this issue of the Revue des Mines, we will show you that, even if the task seems insurmountable, solutions do exist thanks to technologies – both new products and new processes – that are becoming ever more efficient at meeting the needs of the world’s citizens. And efficient means lower costs, a smaller environmental footprint AND greater user comfort.

As for new materials, we will be presenting an indefinitely recyclable polymer for the manufacture of sportswear (Brett Helms, founder, Cyklos Materials, USA) and non-isocyanate polyurethane foams that provide thermal insulation for buildings whilst being recyclable (Jean-Marie Raquez, Professor, University of Mons, Belgium). We also devote an article to new generations of batteries that use fewer critical materials (NMC 9-0.5-0.5 lithium batteries vs NMC 5-3-2, which use four times less cobalt) or none at all (sodium batteries), not to mention the recycling of these batteries – so-called “urban mining” (Shirley Meng, Professor, University of Chicago, USA).

As regards new processes, we will first look at methane pyrolysis, a process invented at Mines Paris – PSL and utilised by the American company Monolith, which enables the co-production of hydrogen and carbon black (Laurent Fulcheri, Professor, Mines Paris – PSL, France), as well as the transformation of refined germanium into high-purity single crystals to manufacture high-performance solar cells for space applications (Gervais Jacques, Executive Chairman, 5N Plus, Canada). We will also discuss vertical extrusion for the development of cheaper medicines with no side effects for the treatment of infectious diseases or cancers (Victoire de Margerie, Executive Chair, Rondol Industrie, France), as well as the use of quantum technology to discover deeper mineral deposits and reduce the environmental impact of their exploration (Cathy Foley, former Chief Scientist to the Australian Government).

At the product-process interface, the example of vitrimers—invented by Ludwik Leibler at ESPCI and now being developed by the start-up Mallinda in Colorado (Philip Taynton, CEO, Mallinda, USA)—illustrates that it is possible both to make a product recyclable and to reduce its cost through a faster manufacturing process that generates less waste.

Of course, artificial intelligence is also at the heart of the article by Greg Mulholland, who founded Citrine in California ten years ago, in which he demonstrates that AI applied to materials does not replace scientific expertise, but rather enhances it and accelerates its industrial deployment. Finally, the case put forward by Manoelle Lepoutre, President of the French Academy of Technologies, highlights two categories of technology for accelerating France’s reindustrialisation: new materials for energy, and biomaterials and bio-based materials.

I would like to extend my warmest thanks to my colleagues and friends in France and around the world who have contributed to this issue. I hope you all enjoy reading this – and I hope that, by the end of this special report, you will share our conviction that materials technology is essential for maintaining and developing industries that are both environmentally friendly AND competitive, particularly in France.