Additive manufacturing of aerogels: Recent advancements and innovations

Aerogels are a unique class of nanostructured materials renowned for their exceptional properties, including ultralow density, outstanding thermal insulation, and low dielectric constant. Traditionally, aerogels have been fabricated through sol-gel processing in various geometries; however, the emergence of additive manufacturing (AM) has revolutionized their processing by introducing unprecedented design flexibility. AM offers significant advantages such as customized geometries, tailored structures, and enhanced scalability for practical and industrial applications. This review provides an in-depth analysis of recent advancements in the AM of aerogels, beginning with a discussion on the fundamentals of aerogel materials, including their sol-gel processing, drying techniques, and formability. Both organic and inorganic aerogels are explored, emphasizing their unique properties and potential applications. The review then delves into the concept of AM, categorizing its various approaches, and examines cutting-edge AM techniques for aerogel fabrication, such as direct ink writing (DIW), direct cryo writing (DCW), inkjet printing, and vat polymerization (VP). Furthermore, post-processing strategies to enhance the structural and functional properties of additively manufactured aerogels are discussed, highlighting their transformative potential across diverse fields.