june W

This article introduces a novel design framework for attaining desired structural transformations in architected materials, which is central to embodying machine-like functionalities for various applications such as soft robotics, wearable technologies, and mechanical computers. The framework utilizes magnetic encoding to generate programmed deformation fields within the soft material. The magnetic interactions offer high programmability and enable pixel-level control over the reconfigurability of architected materials.

Abstract

A class of transformable materials is introduced with magnetic defect-defined switchable configurations. The soft material can be magnetically-programmed to transform into various encoded patterns utilizing the rich interplay of magnetic interactions and instability phenomenon. The strategy allows us to break the limit of admissible configurations of the instability-induced patterns that dictate the post-transformation behavior. The phenomenon is experimentally realized in a material system consisting of periodically distributed magnetic inclusions in a soft matrix. The programmable magnetic interactions between the inclusions act as smart defects redirecting the material transformations to targeted geometric configurations. Moreover, the role of magnetic spacing and field strength is systematically investigated to map the transition between mechanically-dominant and magnetics-dominant instability patterns. Lastly, the idea of reconfigurable material design is showcased by embedding binary information in magnetic form, which can be read out through the unique repositioning of inclusions via the applied mechanical deformation.

A novel laser thermal printing technique toward the fabrication of all-in-one flexible intelligent devices is proposed, and a multifunctional intelligent cobweb structure is synthesized for demonstration. The printed intelligent cobweb seamlessly incorporates multifunctional sensing, stimulus response, and actuation, indicating that the proposed technique has great potential in efficiently fabricating miniaturized and multifunctional flexible intelligent devices.

Abstract

A novel laser thermal printing technique toward the fabrication of all-in-one flexible intelligent devices is presented in this work, addressing the existing challenges in their scalable manufacturing and multifunctional performance. The first-ever application of this technique for the synthesis of a multifunctional intelligent cobweb structure is presented. The resultant cobweb integrates a conductive network of multi-walled carbon nanotubes (MWCNTs) and NdFeB magnetic microparticles within a polydimethylsiloxane (PDMS) matrix, enabling seamless incorporation of sensing, stimulus response, and actuation functionalities. The cobweb exhibits multifunctional sensing characteristics, including a 2.37 strain gauge factor and a 0.312%·mT⁻¹ magnetic field sensitivity, excellent stability exceeding 3500 cycles. Furthermore, the cobweb achieves accurate capture of a beetle on the basis of real-time sensing of the beetle, verifying its rapid stimulus response characteristics. Meanwhile, the cobweb exhibits an electromagnetic ejection performance with an ejection height of over 33.5 times the size of the projectile, verifying its powerful actuating ability. These results demonstrate the successful integration of multifunctional sensing, stimulus response, and actuation within the cobweb structure, facilitated by the innovative laser thermal printing process. The laser thermal printing technique marks a significant advancement in the efficient fabrication of miniaturized and multifunctional flexible intelligent devices based on thermosetting materials.

A series of antibacterial coatings combining aminoglycosides with metallosupramolecules has been developed. These coatings show excellent antibacterial activity in vitro and in vivo, featuring high drug loading and controlled release. They improve therapeutic outcomes for implant infections and bacterial wounds. Additionally, a real-time drug release monitoring system enhances wound care precision and enables timely clinical interventions.

Abstract

Smart antibacterial coatings with surface-independent methods, on-demand antibiotic release, and real-time drug loading monitoring capabilities have attracted increasing interest in the fields of medical devices, antibiotics delivery platforms, and implantable devices. Addressing the complexity inherent in existing methods, this work innovates by simplifying the synthesis process and integrating aminoglycosides with metallosupramolecules to develop versatile and effective coatings. These coatings not only exhibit exceptional biological activity and efficient antibacterial properties both in vitro and in vivo, but also enable high drug loading and controlled release. Significantly, their application across various devices has demonstrated profound therapeutic effects in treating implant infections and promoting bacterial wound healing. A key advancement of these coatings is the integration of color-changing indicators for real-time monitoring of drug levels, enhancing the precision of wound care, and facilitating timely clinical interventions. This research marks a significant stride in the development of more accessible, bioactive, and smart antibacterial materials, opening new avenues in the field of smart medical coatings.

Adult female desert locusts dig underground roughly three-four times in their lives to lay their eggs, using the two pairs of oviposition valves at the tip of the female's abdomen. This study highlights the evolutionary adaptation of the valve materials to their specific function, suggesting a trade-off between energetic investment and the sufficient, or “good-enough”, performance that is required for survival.

Abstract

Adult female desert locusts (Schistocerca gregaria) dig underground to lay their eggs, ensuring optimal conditions for successful hatching. Digging is performed using the two pairs of oviposition valves at the tip of the female's abdomen. These valves are subjected to considerable shear forces during the repeated digging cycles, potentially leading to wear over time. The resilience of the valves is investigated by analyzing the relationship between digging experience and valve damage and wear throughout the female locust's life. The findings reveal the ability of the valves to withstand the significant shear forces encountered during digging. Despite this resilience, however, perceptible limitations in the valves’ mechanical durability against wear are observed. Toward the end of the female locust's life, the valves show substantial signs of wear, indicating effective performance but with limited longevity, i.e., a designated life span that enables successful oviposition for ca. four oviposition cycles. A comparison of the valve material with that of the animals’ mandibles, which are used continuously throughout their life and show remarkable wear-resistance, further highlights the evolutionary adaptation of the valve materials to their specific function, suggesting a trade-off between energetic investment and the sufficient, or “good-enough”, performance that is required for survival.

Bioinspired morphing swimmers are designed integrating chemical protein motors and photoresponsive liquid crystal networks. This approach gives access to five interchangeable modes of locomotion within a single swimming robot via shape-morphing of the soft structure. The proposed design, which mimics the mechanisms of surface gliding and posture change of semiaquatic insects, offers untethered and orthogonal power and control for small-scale swimming soft robots.

Abstract

Aquatic insects have developed versatile locomotion mechanisms that have served as a source of inspiration for decades in the development of small-scale swimming robots. However, despite recent advances in the field, efficient, untethered, and integrated powering, actuation, and control of small-scale robots remains a challenge due to the out-of-equilibrium and dissipative nature of the driving physical and chemical phenomena. Here, we have designed small-scale, bioinspired aquatic locomotors with programmable deterministic trajectories that integrate self-propelled chemical motors and photoresponsive shape-morphing structures. A Marangoni motor system is developed integrating structural protein networks that self-regulate the release of chemical fuel with photochemical liquid crystal network (LCN) actuators that change their shape and deform in and out of the surface of water. While the diffusion of fuel from the motor system regulates the propulsion, the dissipative photochemical deformation of LCNs provides locomotors with control over the directionality of motion at the air-water interface. This approach gives access to five different but interchangeable modes of locomotion within a single swimming robot via morphing of the soft structure. The proposed design, which mimics the mechanisms of surface gliding and posture change of semiaquatic insects such as water treaders, offers solutions for autonomous swimming soft robots via untethered and orthogonal power and control.

In this study, a strain sensor inspired by the architecture of butterfly's wings is proposed. It comprises two conductive layers and wrinkles/holes structures. Its linearity is greater than 0.98 over 120% of the full operating range, and the sensor has excellent superhydrophobic properties. Their possible applications in monitoring the motion of underwater vehicles are explored.

Abstract

Flexible strain sensors are of great significance in health monitoring, wearable electronic devices, intelligent robot sensing, and other fields. Most of the reported works focus on the enhancement of sensitivity or working range, while linearity is ignored and exhibits strong nonlinearity. Conflict among performances remains a serious challenge for the development of flexible strain sensors. Herein, inspired by the architecture of butterfly's wings, a strain sensor with double conductive layers and wrinkles/holes structures is proposed. The fabricated sensor shows a high linearity of >0.98 over a full working strain range of 120%, and a linearity of up to 0.999 within a strain range of 0%–30%. Apart from that, the sensor also presents a sensitivity of 8.28, high stability over 40 000 cycles when subjected to a full-scale strain, as well as a water contact angle of >167.4°. Meanwhile, strains as low as 0.075% can be identified, while a maximum frequency of 40 Hz can be responded to for the sensor. It is demonstrated that the sensor is capable of enabling flexible grippers to sense and monitor the motions of underwater vehicles, indicating its greater potential for diverse applications, such as human–machine interaction, marine environmental protection, and biological research.

Miniature robots have great prospects to transform targeted drug delivery. Here, a miniature soft robot is proposed, which can dispense four types of drugs with reprogrammable drug-dispensing sequence and dosage. This soft robot can inspire unprecedented, targeted combination therapy, where multiple drugs must be delivered to various disease sites, each with a specific sequence and dosage of drugs.

Abstract

Miniature robots are untethered actuators, which have great prospects to transform targeted drug delivery because they can potentially deliver high concentrations of medicine to the disease site(s) with minimal complications. However, existing miniature robots cannot perform advanced targeted combination therapy; majority of them can at most transport one type of drug, while those that can carry multiple drugs are unable to change their drug-dispensing sequence and dosage. Furthermore, the latter robots cannot transport more than three types of drugs, selectively dispense their drugs, maintain their mobility, or release their drugs at multiple sites. Here, a millimeter-scale soft robot is proposed, which can be actuated by alternating magnetic fields to dispense four types of drugs with reprogrammable drug-dispensing sequence and dosage (dispensing rates: 0.0992–0.231 µL h⁻¹). This robot has six degrees-of-freedom motions, and it can deliver its drugs to multiple desired sites by rolling and two-anchor crawling across unstructured environments with negligible drug leakage. Such dexterity is highly desirable and unprecedented for miniature robots with drug-dispensing capabilities. The soft robot therefore has great potential to enable advanced targeted combination therapy, where four types of drugs must be delivered to various disease sites, each with a specific sequence and dosage of drugs.

The integration of shape-transformable liquid metal nanoparticles (LMNPs) is first unveiled into 3D printing to create hybrid soft robots with controlled mechanical properties and deformability. This method allows direct printing of one-piece or assembled hybrid robots using a single LMNPs-integrated ink recipe, enabling precise control of mechanical and shape memory properties for applications like grippers, bioinspired motors, and rehabilitation devices.

Abstract

In recent years, soft robotics has emerged as a rapidly expanding frontier research field that draws inspiration from the locomotion mechanisms of soft-bodied creatures in nature to achieve smooth and complex motion for diverse applications. However, the fabrication of soft robots with hybrid structures remains challenging due to limitations in material selection and the complex, multi-step processes involved in traditional manufacturing methods. Herein, a novel direct one-step additive manufacturing (3D printing) approach is introduced for the fabrication of hybrid robots composed of soft and rigid components for sophisticated tasks. Inspired by the shape-transformable liquid metal nanoparticles (LMNPs), a functional material toolkit with tuneable mechanical properties and deformability is developed by integrating differently shaped gallium-based nanoparticles (GNPs) into the 3D printing polymers. Then the direct printing of assembled or one-piece hybrid soft-rigid robots is presented through a single recipe of GNPs-integrated inks. This fabrication method enables precise control of the mechanical properties and shape memory properties within the hybrid structures of robot body with a customized structure design. Their capabilities are further demonstrated through the design and fabrication of hybrid robots as high-precision gripper, bioinspired motor, and hand rehabilitation device.

In this study, a ferromagnetic liquid robot (FMLR) with tunable modulus (0.1–2018 Pa) applied to thrombus removal in complex blood vessels is developed. Besides, in medical robotic applications, FMLR can be used in telerobotic neurointerventional. This study introduces an efficient approach for thrombus elimination, broadening the utilization of FMLRs within the realm of clinical medicine.

Abstract

Thrombosis is a significant threat to human health. However, the existing clinical treatment methods have limitations. Magnetic soft matter is used in the biomedical field for years, and ferromagnetic liquids exhibit tunable stiffness and on-demand movement advantages under magnetic fields. In this study, a ferromagnetic liquid robot (FMLR) is developed and applied it to thrombus removal in complex blood vessels. The FMLR consisted of Fe₃O₄ magnetic nanoparticles and dimethyl silicone oil. The FMLR can pass through a narrow complex maze through shape deformation by tailoring the intensity and direction of the external magnetic field. Finite element simulation analysis is used to validate the mechanism of controllable FMLR movements. Importantly, the storage modulus of FMLR can be tuned from 0.1 to 2018 Pa by varying the external magnetic intensity, ensuring its effectiveness in removing rigid and stubborn thrombi present on the vascular walls. Toward medical robotic applications, FMLR can be used in telerobotic neurointerventional. Experiments demonstrating the capability of FMLR to remove thrombi in the ear veins of rabbits are conducted. This study introduces an efficient approach for thrombus elimination, broadening the utilization of FMLRs within the realm of clinical medicine.

Mechanoresponsive color-changing materials that can reversibly and resiliently change color in response to stress are highly desirable for diverse technologies in optics, sensors, and robots; however, such materials are rarely achieved. This work reports a fatigue-resistant mechanoresponsive color-changing hydrogel that exhibits reversible, resilient, and predictable color changes under mechanical stress, for tactile robots by translating tactile sensations into visual images.

Abstract

Mechanoresponsive color-changing materials that can reversibly and resiliently change color in response to mechanical deformation are highly desirable for diverse modern technologies in optics, sensors, and robots; however, such materials are rarely achieved. Here, a fatigue-resistant mechanoresponsive color-changing hydrogel (FMCH) is reported that exhibits reversible, resilient, and predictable color changes under mechanical stress. At its undeformed state, the FMCH remains dark under a circular polariscope; upon uniaxial stretching of up to six times its initial length, it gradually shifts its color from black, to gray, yellow, and purple. Unlike traditional mechanoresponsive color-changing materials, FMCH maintains its performance across various strain rates for up to 10 000 cycles. Moreover, FMCH demonstrates superior mechanical properties with fracture toughness of 3000 J m⁻², stretchability of 6, and fatigue threshold up to 400 J m⁻². These exceptional mechanical and optical features are attributed to FMCH's substantial molecular entanglements and desirable hygroscopic salts, which synergistically enhance its mechanical toughness while preserving its color-changing performance. One application of this FMCH as a tactile sensoris then demonstrated for vision-based tactile robots, enabling them to discern material stiffness, object shape, spatial location, and applied pressure by translating stress distribution on the contact surface into discernible images.

Hemostatic Peptide Hydrogel

The immemorial Chinese fairy tale “Nuwa fixing the sky” is used to metaphor the hemostatic process of hemostatic peptide hydrogel (HPH) in article number 2405290 by Chaoqiang Fan, Malcolm Xing, Shiming Yang, and co-workers. The hole in the sky and the pouring flood from Tianhe River are metaphors for the wound and severe hemorrhage. The goddess Nuwa is using colorful stones which represent HPH, triggered by the blue laser to halt bleeding and saving lives.