Textile products have been an indispensable part of daily human life for 27,000 years. The textiles used by humans evolved from early natural fibers such as cotton, wool, linen, and silk to modern synthetic fibers. Fabrics provide essential functions for humans, serving as a second layer of skin for purposes such as insulation and protection [1,2]. With advancements in manufacturing technologies and the development of textile materials, textile applications have become increasingly diverse and widespread. Life without textiles cannot be imagined. Moreover, with improvements in living standards and advances in science and technology, textile functions have expanded beyond simple warmth, insulation, comfort, and aesthetics. Textiles are now designed with antimicrobial properties [3,4], ultraviolet (UV) resistance [5], flame retardancy [6], waterproofing [7], self-cleaning [8,9], cut resistance [10], and sensing capabilities in intelligent wearable fabrics. The pursuit of intelligence and multifunctionality has broadened the scope of textile applications. Functionalized textiles enhance resource efficiency and contribute to sustainable development. As consumer demand for personalization and customization increases, companies offer broader ranges of textile choices in their products to meet individual needs.

Currently, the addition of a functional master batch (e.g., UV shielding agents) during the spinning process and the surface modification of fibers/fabrics are the most important methods for achieving textile functionalization. However, some functional masterbatches have problems such as toxicity, anomalous diffusion, and agglomeration, which limit their further application [11]. Surface modification, the mainstream method for textile functionalization, involves grafting or coating fiber surfaces to endow textiles with additional functions. Traditional surface modification methods, including mat dry curing [12,13], coating [14], microwave irradiation [15,16], electrophoretic deposition [17], layer-by-layer assembly [18], enzyme immobilization [19], and the sol-gel method [20,21], have been widely utilized by industry to enhance the properties of fiber materials or endow them with multifunctionality to meet market demands. However, several common problems occur when using these methods: (i) these processes significantly increase the weight of the fibers and change the original flexibility of the materials; (ii) the realization of functionality is often at the expense of comfort in the existing functional products; and (iii) the laundering/abrasion durability is poor because the chemical bonding between the coating and the fabric is weak, which largely limits the application of functional textiles. Therefore, more efficient strategies must be developed to improve the properties of fiber materials while simplifying the operational process.

Atomic layer deposition (ALD), a new functionalization method and technology, has been used to achieve multifunctionality in fibers and fabrics [[22], [23], [24], [25], [26]]. ALD is a special chemical vapor deposition technique that forms thin films using pulsed alternating passage of gaseous precursors into the reaction chamber and chemical adsorption reactions on the surface of the deposited substrate. ALD exhibits excellent three-dimensional (3D) conformality, large-area uniformity, and precise sub-monolayer film thickness control, which are difficult to achieve with conventional physical or chemical vapor deposition [[27], [28], [29]]. These advantages make ALD a good candidate for the fabrication of functionalized fabrics [[30], [31], [32], [33], [34], [35]].

In this article, ALD technology is first summarized and its growth mechanism is discussed in detail. The factors influencing ALD are then examined, and commonly used ALD-derived technologies such as plasma-enhanced ALD (PEALD) and molecular layer deposition (MLD) are compared. Subsequently, the research progress and breakthroughs in inorganic nanofilms prepared by ALD to achieve multifunctional properties on textiles, such as antimicrobial properties, UV-resistance, heat-insulation, multifunctional wetting, structural coloring, thermoelectric (TE) elements, and flexible sensing are reviewed. Finally, the future developments and possible challenges of ALD for the large-scale production of multifunctional fabrics are presented, which are expected to drive the development of next-generation advanced functional textiles.