Antibiotic contamination has emerged as a global challenge, increasing antibiotic resistance and threatening human health and ecosystems. Bioremediation using microorganism offers sustainable methods to degrade such pharmaceutical contaminants. However, these microorganisms exhibit reduced activity under high-stress conditions, and are difficult to recycle and potentially leak into environment as microbial pollutions. Here we report bioprinted retrievable microalgae hydrogel networks (MHNs) by confining living microalgae in double-network hydrogels, which achieves enhanced antibiotic degradation (>99.3%) and recyclable ability. Particularly, coating MHN with tannic acid (MHN@TA) generates a semipermeable membrane to prevent the leakage of microalgae (<0.7% for 7 days), ensuring the containment of potential microbial biohazards. The biohybrid system protects the biological activity of microalgae, enabling antibiotic degradation up to 400 mg L⁻¹. Free-standing MHN@TA fencing systems are also manufactured to demonstrate their practical applications. This study provides insights of microalgae-material interactions in bioremediation and offers design rationales for biohybrid systems.

Compared to relatively mature audio and video human-machine interfaces, providing accurate and immersive touch sensation remains a challenge owing to the substantial mechanical and neurophysical complexity of touch. Touch sensations during relative lateral motion between a skin-screen interface are largely dictated by interfacial friction, so controlling interfacial friction has the potential for realistic mimicry of surface texture, shape, and material composition. In this work, we show a large modulation of finger friction by locally changing surface temperature. Experiments showed that finger friction can be increased by ~50% with a surface temperature increase from 23° to 42°C, which was attributed to the temperature dependence of the viscoelasticity and the moisture level of human skin. Rendering virtual features, including zoning and bump(s), without thermal perception was further demonstrated with surface temperature modulation. This method of modulating finger friction has potential applications in gaming, virtual and augmented reality, and touchscreen human-machine interaction.

Biological species can walk, swim, fly, jump, and climb with fast response speeds and motion complexity. These remarkable functions are accomplished by means of soft actuation organisms, which are commonly composed of muscle tissue systems. To achieve the creation of their biomimetic artificial counterparts, various biomimetic stimuli-responsive materials have been synthesized and developed in recent decades. They can respond to various external stimuli in the form of structural or morphological transformations by actively or passively converting input energy into mechanical energy. They are the core element of soft actuators for typical smart devices like soft robots, artificial muscles, intelligent sensors and nanogenerators. Significant progress has been made in the development of bioinspired stimuli-responsive materials. However, these materials have not been comprehensively summarized with specific actuation mechanisms in the literature. In this review, we will discuss recent advances in biomimetic stimuli-responsive materials that are instrumental for soft actuators. Firstly, different stimuli-responsive principles for soft actuators are discussed, including fluidic, electrical, thermal, magnetic, light, and chemical stimuli. We further summarize the state-of-the-art stimuli-responsive materials for soft actuators and explore the advantages and disadvantages of using electroactive polymers, magnetic soft composites, photo-thermal responsive polymers, shape memory alloys and other responsive soft materials. Finally, we provide a critical outlook on the field of stimuli-responsive soft actuators and emphasize the challenges in the process of their implementation to various industries.

With the commercialization of haptic devices, understanding behavior under various environmental conditions is crucial for product optimization and cost reduction. Specifically, for surface haptic devices, the dependence of the friction force and the electroadhesion effect on the environmental relative humidity and the finger hydration level can directly impact their design and performance. This article presents the influence of relative humidity on the finger-surface friction force and the electroadhesion performance. Mechanisms including changes to Young's modulus of skin, contact angle change and capillary force were analyzed separately with experimental and numerical methods. Through comparison of the calculated capillary force in this paper and the electroadhesion force calculated in published papers, it was found that electrowetting at high voltage could contribute up to 60% of the total friction force increase in electroadhesion. Therefore, in future design of surface haptic devices, the effect of electrowetting should be considered carefully.

This review analyses the state-of-the-art transfer methods of 2D materials, evaluates their strengths and limitations, and highlights emerging trends like reconfigurable transfer, all-transfer strategies and broad applications in diverse fields.