Yuxuan Sun

As the demand for advanced actuation strategies in soft robotics and intelligent material systems grows, magnetoactive soft actuators have attracted increasing attention for their ability to achieve flexible shape transformations through remote and untethered control. However, existing designs typically rely on continuous high magnetic fields to generate large deformations, limiting both efficiency and applicability, especially under constrained boundary conditions. Here we report a hemispherical bistable soft actuator embedded with magnetic microparticles, which enables substantial shape changes under low-intensity pulsed magnetic torques and remains stable in two configurations without external fields. We analyze the relationship between design parameters and actuator performance to clarify the bistable mechanism, and show that the actuator can achieve a large shape change ratio exceeding 0.8 under magnetic fields below 20 mT. We further demonstrate its versatility through three applications: a high-efficiency soft pump with closed-loop fluid control, a reprogrammable metamaterial, and a variable-stiffness soft gripper.

Sponge materials offer a unique combination of porosity, flexibility, compressibility, and responsiveness, yet their potential as primary elements in shape‐morphing systems remains underexplored. Here, a modular shape‐morphing platform constructed entirely from pre‐compressed cellulose sponges, referred to as “foambots” is presented. Each block is geometrically patterned to induce anisotropic swelling, enabling programmable volumetric morphing upon hydration without external power or electronics. By stacking and orienting foambots in designed configurations, complex 3D structures capable of untethered transformation in aquatic environments are created. The large volumetric expansion (≈1:10 before and after morphing) allows for a unique compact form for easy transport and deployment. How key design parameters (block length, hole position, and orientation) govern bending behavior are systematically investigated, and inverse design strategies to achieve target geometries are demonstrated. Using this approach, two functional applications are realized, leveraging foambots's programmable large volumetric expansion for deployable floating structures: a wearable flotation module that wraps around the user's limb, and a self‐propelling boat capable of expanding ≈463% of its original size when deployed, autonomous deploying, and traveling on water. These results establish cellulose sponge as a unique, sustainable material for morphing applications and introduce a scalable, low‐cost strategy for creating deployable and reconfigurable soft structures.

Negative magnetophoresis-based magnetic levitation (MagLev) is a label-free and simple method to levitate and manipulate nonmagnetic materials, which is a recent research topic of interest in density-based analysis. However, the existing MagLev mainly uses two permanent magnets with a longitudinal symmetry structure, facing difficulties in achieving both a large measurement range and high measurement sensitivity simultaneously. To solve this, a novel asymmetrical cylindrical MagLev configuration is proposed involving two cylindrical magnets with different thicknesses. On this basis, the characteristics of magnetic force at different magnet spacings are investigated, and the levitation behavior of the samples with different densities is explored. According to the numerical and experimental results, it is interestingly found that two different continuous functional regions with inward radial magnetic forces can be formed for density measurement by adjusting the magnet spacing. The functional measurement regions at small magnet spacing and large magnet spacing serve a large measurement range and a high measurement sensitivity, respectively. Importantly, the measurement range and sensitivity in the new MagLev are both better than conventional MagLev. These findings are of significance to understanding the MagLev process and to promote its practicality.

Untethered capsules hold clinical potential for the diagnosis and treatment of gastrointestinal diseases. Although considerable progress has been achieved recently in this field, the constraints imposed by the narrow spatial structure of the capsule and complex gastrointestinal tract environment cause many open-ended problems, such as poor active motion and limited medical functions. In this work, we describe the development of small-scale magnetically driven capsules with a distinct magnetic soft valve made of dual-layer ferromagnetic soft composite films. A core technological advancement achieved is the flexible opening and closing of the magnetic soft valve by using the competitive interactions between magnetic gradient force and magnetic torque, laying the foundation for the functional integration of both drug release and sampling. Meanwhile, we propose a magnetic actuation strategy based on multi-frequency response control and demonstrate that it can achieve effective decoupled regulation of the capsule’s global motion and local responses. Finally, through a comprehensive approach encompassing ideal models, animal ex vivo models, and in vivo assessment, we demonstrate the versatility of the developed magnetic capsules and their multiple potential applications in the biomedical field, such as targeted drug delivery and sampling, selective dual-drug release, and light/thermal-assisted therapy.