Human-integrated devices include wearable and implantable devices for monitoring vital human signals or interacting with the human body. [1-3] The human-integrated devices needed to be tethered to the organs or the human skin for implementing their functions such as sensing and energy harvesting. [4-18] The economical, agile, customizable manufacturing, and integration of multifunctional device modules into networked systems with mechanical compliance and robustness will enable unprecedented human-integrated smart wearables [19-23] and usher in exciting opportunities in emerging technologies such as electronics, [24-29] wearable computation, [30-36] human-machine interface, [37-42] robotics, [43-48] and advanced healthcare. [49-54] The fabrication of stateof-the-art microelectronics involves hightemperature processing steps, which are generally incompatible with the flexible substrates (e.g., paper, polymer, fiber, etc.) [55-61] widely used in the wearable devices. Moreover, the current microfabrication technologies are not well positioned to process the emerging functional nanomaterials (e.g., nanowires [NWs] and 2D materials). [62-65] Such incomparability severely limits the pace of deploying these emerging materials (despite their unprecedented properties) in wearable and flexible device technologies. The additive manufacturing (AM) processes have emerged as potential candidates for addressing the earlier limitations of the current microfabrication technologies in fabricating flexible/wearable printed devices with diversified functionalities, e.g., energy harvesting/storage, sensing, actuation, and computation, leveraging advantages such as maskless processing, versatile ink formulation, low cost, low processing temperature, and scalability. [66-71] Researchers have devoted tremendous efforts to develop the related technologies, and several reviews have provided excellent discussions on the material formulation and process aspects of AM techniques. [63,72-79] However, to our best knowledge, there are few review reports about the ink-based additive nanomanufacturing of functional materials for human-integrated smart wearables. To fill this gap, here we review the recent progress in ink-based
