Combination therapy is a promising approach to enhancing antitumor efficacy and overcoming multidrug resistance. Intravesical instillation of Bacillus Calmette–Guérin (BCG) combined with chemotherapy has been employed to improve bladder cancer treatment efficacy, but outcomes are often limited by high-dose drug irritation, poor patient tolerance, and insufficient targeting. To overcome these limitations, we propose a microrobot (MR)-based targeted drug delivery strategy for precise co-delivery of BCG and paclitaxel to bladder tumors, facilitating sustained drug release and minimizing off-target effects. The MRs are fabricated using a layer-by-layer assembly technique, incorporating antitumor drugs, magnetic nanoparticles, and viable BCG. Under the synergistic action of external magnetic fields and hydrogen microbubbles generated through chemical reactions, the MRs achieve targeted navigation and effective accumulation within the 3-dimensional tumor microenvironment. Subsequently, the combined chemotherapeutic and immunostimulatory effects effectively inhibit tumor progression. This approach not only minimizes off-target effects but also facilitates sustained drug release. Additionally, a wearable magnetic fixation device based on a Halbach array is employed to fixate the MRs at the targeted region, further improving drug retention and enhancing therapeutic efficacy. The experimental results demonstrate that this MR-based delivery system holds considerable potential for clinical translation into combination therapies for bladder cancer.

Micro/nano devices (MNDs) are characterized by miniaturization, high precision, and multifunctional integration, making them highly suitable for use in areas such as microrobotics, biomedical devices and electronic sensors. Their fabrication requires exceptional precision in structural integrity, material control, and functional integration. Traditional micro/nano fabrication techniques face inherent limitations in constructing complex three-dimensional (3D) architectures and integrating multiple materials. While additive manufacturing (AM) provides flexibility, challenges remain in material alignment control, microstructural organization, and multifunctional integration. To overcome these limitations, field-assisted additive manufacturing (FAM) has emerged as a promising approach that combines magnetic, acoustic, or electric fields to regulate material alignment, microstructural organization, and spatial alignment. This capability improves fabrication precision, enhances material anisotropy and facilitates functional integration. This review systematically explores the mechanisms, fabrication process, and functional integration of FAM in the framework of nozzle-based and vat photopolymerization-based, while further exploring their applications in microrobotics, biomedical devices, and electronic sensors. Moreover, this review provides a comparative overview of different FAM approaches, highlighting their respective characteristics, typical applications, and unique advantages. In addition, the major challenges facing FAM research are comprehensively assessed and future directions are explored, including advances in spatial precision control capability, intelligent control for process integration, and multi-field coupling optimization. This review establishes a foundational theoretical framework that can serve as a systematic reference for micro/nano manufacturing researchers to promote the development of FAM for high-performance micro/nano device fabrication.

Micro/nanorobots have exhibited excellent application potential in the biomedical field, such as drug delivery, minimally invasive surgery, and bio-sensing. Furthermore, in order to achieve practical application, it is essential for swimming micro/nanorobots to navigate towards specific targets or adjust their speed and morphology in complete environments. The navigation of swimming micro/nanorobots with temporal and spatial precision is critical for fulfilling the demand of applications. Here, we introduced a fully integrated wearable control system for micro/nanorobots navigation and manipulation, which is composed of a multifunctional sensor array, an artificial intelligence (AI) planner, and a magnetic field generator. The sensor array could perceive real-time changes in gestures, wrist rotation, and acoustic signals. AI planner based on machine learning offers adaptive path planning in response to dynamically changing signals to generate magnetic fields for the on-demand manipulation of micro/nanorobots. Such a novel, feasible control strategy was validated in the biological experiment in which cancer cells were targeted and killed by photothermal therapy using micro/nanorobots and integrated control platform. This wearable control system could play a crucial role in future intelligent medical applications and could be easily reconfigured toward other medical robots’ control.