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Abstract Active metamaterials are a type of metamaterial with tunable properties enabled by structural reconfigurations. Existing active metamaterials often achieve only a limited number of structural reconfigurations upon the application of an external load across the entire structure. Here, a selective actuation strategy is proposed for inhomogeneous deformations of magneto‐mechanical metamaterials, which allows for the integration of multiple elastic wave‐tuning functionalities into a single metamaterial design. Central to this actuation strategy is that a magnetic field is applied to specific unit cells instead of the entire metamaterial, and the unit cell can transform between two geometrically distinct shapes, which exhibit very different mechanical responses to elastic wave excitations. The numerical simulations and experiments demonstrate that the tunable response of the unit cell, coupled with inhomogeneous deformation achieved through selective actuation, unlocks multifunctional capabilities of magneto‐mechanical metamaterials such as tunable elastic wave transmittance, elastic waveguide, and vibration isolation. The proposed selective actuation strategy offers a simple but effective way to control the tunable properties and thus enhances the programmability of magneto‐mechanical metamaterials, which also expands the application space of magneto‐mechanical metamaterials in elastic wave manipulation. 

Abstract Aggressive cancers, characterized by high metastatic potential and resistance to conventional therapies, present a significant challenge in oncology. Current treatments often fail to effectively target metastasis, recurrence, and the immunosuppressive tumor microenvironment, while causing significant off‐target toxicity. Here, superparamagnetic copper iron oxide nanoparticles (SCIONs) as a multifunctional platform that integrates magnetic hyperthermia therapy, immune modulation, and targeted chemotherapeutic delivery, aiming to provide a more comprehensive cancer treatment is presented. Specifically, SCIONs generate localized hyperthermia under an alternating magnetic field while delivering a copper‐based anticancer agent, resulting in a synergistic anticancer effect. The hyperthermia induced by SCIONs caused ER stress and ROS production, leading to significant tumor cell death, while the copper complex further enhanced oxidative stress, ferroptosis, and apoptosis. Beyond direct cytotoxicity, SCIONs disrupted the tumor microenvironment by inhibiting cancer‐associated fibroblasts, downregulating epithelial‐mesenchymal transition markers, and reducing cell migration and invasion, thereby limiting metastasis. Additionally, SCION‐based therapy reprogrammed the immune microenvironment by inducing immunogenic cell death and enhancing dendritic cell activation, resulting in increased CD8+ T cell infiltration and amplified antitumor immunity. This integrated approach targets primary and metastatic tumors while mitigating immunosuppression, offering a promising next‐generation therapy for combating cancer with enhanced efficacy and reduced side effects. 

Abstract Navigating the complex and high‐flow environment of human vasculature remains a major challenge for conventional endovascular tools and externally actuated tethered systems. While catheter‐based approaches are the clinical standard, their limited steerability and force transmission hinder access to tortuous or distal vessels, especially in the brain. Untethered robotic systems have emerged as a promising alternative for enhanced flexibility and reachability. However, most designs struggle against the high, pulsatile blood flow in human arteries. Here, the study presents a magnetically actuated milli‐spinner robot that overcomes existing limitations in navigating complex and high‐flow vasculature. Capable of swimming at 23 cm·s⁻¹(73 body lengths per second), the milli‐spinner enables rapid, stable navigation through complex vasculature. This performance is driven by its hollow cylindrical structure with integrated helical fins and slits, which together generate a spinning‐induced flow field that enhances propulsion efficiency and allows the robot to maintain stability and control even in dynamic, pulsatile blood flow environments. In addition to its navigation capabilities, the milli‐spinner enables multifunctional treatment, including localized suction and shear for efficient clot removal, targeted drug delivery, and in situ embolization for aneurysm treatment. These features establish the milli‐spinner as a versatile and powerful platform for next‐generation, untethered endovascular interventions. 

Elephant trunks are capable of complex, multimodal deformations, allowing them to perform task‐oriented high‐degree‐of‐freedom (DOF) movements pertinent to the field of soft actuators. Despite recent advances, most soft actuators can only achieve one or two deformation modes, limiting their motion range and applications. Inspired by the elephant trunk musculature, a liquid crystal elastomer (LCE)‐based multi‐fiber design strategy is proposed for soft robotic arms in which a discrete number of artificial muscle fibers can be selectively actuated, achieving multimodal deformations and transitions between modes for continuous movements. Through experiments, finite element analysis (FEA), and a theoretical model, the influence of LCE fiber design on the achievable deformations, movements, and reachability of trunk‐inspired robotic arms is studied. Fiber geometry is parametrically investigated for 2‐fiber robotic arms and the tilting and bending of these arms is characterized. A 3‐fiber robotic arm is additionally studied with a simplified fiber arrangement analogous to that of an actual elephant trunk. The remarkably broad range of deformations and the reachability of the arm are discussed, alongside transitions between deformation modes for functional movements. It is anticipated that this design and actuation strategy will serve as a robust method to realize high‐DOF soft actuators for various engineering applications. 

Abstract Shape morphing that transforms morphologies in response to stimuli is crucial for future multifunctional systems. While kirigami holds great promise in enhancing shape-morphing, existing designs primarily focus on kinematics and overlook the underlying physics. This study introduces a differentiable inverse design framework that considers the physical interplay between geometry, materials, and stimuli of active kirigami, made by soft material embedded with magnetic particles, to realize target shape-morphing upon magnetic excitation. We achieve this by combining differentiable kinematics and energy models into a constrained optimization, simultaneously designing the cuts and magnetization orientations to ensure kinematic and physical feasibility. Complex kirigami designs are obtained automatically with unparalleled efficiency, which can be remotely controlled to morph into intricate target shapes and even multiple states. The proposed framework can be extended to accommodate various active systems, bridging geometry and physics to push the frontiers in shape-morphing applications, like flexible electronics and minimally invasive surgery. 

Abstract 2D metamaterials have immense potential in acoustics, optics, and electromagnetic applications due to their unique properties and ability to conform to curved substrates. Active metamaterials have attracted significant research attention because of their on‐demand tunable properties and performances through shape reconfigurations. 2D active metamaterials often achieve active properties through internal structural deformations, which lead to changes in overall dimensions. This demands corresponding alterations of the conforming substrate, or the metamaterial fails to provide complete area coverage, which can be a significant limitation for their practical applications. To date, achieving area‐preserving active 2D metamaterials with distinct shape reconfigurations remains a prominent challenge. In this paper, magneto‐mechanical bilayer metamaterials are presented that demonstrate area density tunability with area‐preserving capability. The bilayer metamaterials consist of two arrays of magnetic soft materials with distinct magnetization distributions. Under a magnetic field, each layer behaves differently, which allows the metamaterial to reconfigure its shape into multiple modes and to significantly tune its area density without changing its overall dimensions. The area‐preserving multimodal shape reconfigurations are further exploited as active acoustic wave regulators to tune bandgaps and wave propagations. The bilayer approach thus provides a new concept for the design of area‐preserving active metamaterials for broader applications.