Carbon nanotube sandpaper for atomic-precision surface finishing

Abstract Sandpapers, also known as coated abrasives, have served as the most familiar surface finishing tools since their first invention in the 13th century. However, they remain unsuitable for advanced industries requiring nanometer-level precision due to limitations in abrasive uniformity and detachment. Here, we introduce a nano-sandpaper that employs vertically aligned carbon nanotubes (VACNTs) with high aspect ratios as fixed abrasives, achieving an unprecedented grit number of 258 billion, over 500,000 times higher than that of conventional sandpapers. The high aspect ratio and outstanding mechanical properties of carbon nanotubes (CNTs) allow for stable embedding within a polyurethane matrix, enabling atomic-level abrasion precision, long-term durability, and tunable performance through engineered micro/nano-scale surface architectures. This nano-sandpaper demonstrates superior polishing precision, material removal rate, and planarization performance across diverse materials, with outstanding durability and environmental sustainability. By integrating robust one-dimensional nanostructures into engineered surface architectures, this study advances nano-to-micro fabrication for atomic-level polishing, paving the way for scalable and sustainable precision manufacturing. Graphical abstract