The escalating demands for smart biomedical systems ignite a significantly growing influence of three-dimensional (3D) printing technology. Recognized as a revolutionary and potent fabrication tool, 3D printing possesses unparalleled capabilities for generating customized functional devices boasting intricate and meticulously controlled architectures while enabling the integration of multiple functional materials. These distinctive advantages arouse a growing inclination toward customization and miniaturization, thereby facilitating the development of cutting-edge biomedical systems. In this comprehensive review, the prevalent 3D printing technologies employed in biomedical applications are presented. Moreover, focused attention is paid to the latest advancements in harnessing 3D printing to fabricate smart biomedical systems, with specific emphasis on exemplary ongoing research encompassing biomedical examination systems, biomedical treatment systems, as well as veterinary medicine. In addition to illuminating the promising potential inherent in 3D printing for this rapidly evolving field, the prevailing challenges impeding its further progression are also discussed. By shedding light on recent achievements and persisting obstacles, this review aims to inspire future breakthroughs in the realm of smart biomedical systems.

Artificial skin with tactile perceptions is anticipated to play a pivotal role in next-generation robotic and medical devices. The primary challenge lies in creating a biomimetic system that seamlessly integrates with the human body and biological systems. The authors have developed an electronic skin (e-skin) that imitates the biological sensorimotor loop through medium-scale circuit integration, boasting low power consumption and solid-state synaptic transistors.

Migraine exhibits a substantial prevalence worldwide. The current diagnostic criteria rests exclusively on clinical characteristics without any objective and reliable means. The calcitonin gene-related peptide (CGRP), as a biomarker for distinguishing migraine, undergoes swift degradation, featuring a half-life of under 10 min, which poses a significant challenge to the point-of-care testing of CGRP in clinical application. Here, a photonic crystal (PC)-based biochip has been developed to detect CGRP via the fluorescence competition assay. The chip integrates the functionalities of fluorescence enhancement and hydrophilic–hydrophobic patterning enrichment, enabling rapid and sensitive detection of CGRP. After investigating the optimal enhancement distance of fluorescence near PCs, the chip allows CGRP detection using <30 µL of saliva at room temperature within 10 min. A minimum detection limit of 0.05 pg/mL is achieved. Furthermore, CGRP concentrations in the saliva of 70 subjects have been tested by PC biochips. The results exhibit strong concordance with the enzyme-linked immunosorbent assay (ELISA), demonstrating a linear correlation coefficient of R² of 0.97. This sensitive detection of markers within such a short duration surpasses the capacities of ELISA, which paves the way for establishing a precise diagnostic framework integrating clinical phenotypes and biomarkers for migraine.

Recently, the collective behavior of micro/nanorobots has shown unprecedented potential in biomedicine and environmental remediation. Collective behavior can work more efficiently, adaptively, and robustly than individual micro/nanorobots. The paradigm of collective behavior needs to be understood in different dimensions, including from individual to cluster, from planar to spatial, and from mono-functional to multifunctional. In this review, the focus will be on summarizing the achievements of collective control of micro/nanorobot swarms in recent years from different dimensions, in an attempt to better understand how the structure and materials of individuals should be designed, how collective behavior should be implemented, and how robots are functionalized to cope with practical applications under the introduction of collective control. The opportunities and challenges that collective control faces at this stage are illustrated to provide perspectives for its future development.

The integration of radials into covalent organic frameworks (COFs) would have a profound effect on their applications in spin devices since such radical arrays can offer scientists an additional dimension to manipulate electron spins and maximize the function of organic optoelectrical devices. However, such realization (especially reversible radicals) is very challenging. In this article, using a fluorene-based benzoquinone-derived monomer (M) as the building unit, we successfully synthesized a boroxine-linked COF (named CityU-3), whose crystallinity and chemical composition were confirmed by powder X-ray diffraction (PXRD), Fourier-transform infrared (FT-IR) spectroscopy, solid-state ¹³C cross-polarization magic-angle-spinning (CP/MAS) NMR, and X-ray photoelectron spectroscopy (XPS). Interestingly, CityU-3 can be converted into its radical form by treating with BF₃·Et₂O, which is associated with a color change from red to black, and vice versa upon heating. The as-formed radicals have been confirmed by electron paramagnetic resonance (EPR) spectroscopy. It is worth pointing out that the cycles between radical formation and disappearance would not affect its crystallinity and structure. The reversible COF radicals would have great applications in organic spin devices.

Large-sized and atomically thin two-dimensional metal thiophosphate materials have been widely exploited in detectors due to their rich physical/chemical properties of high surface area and massive adjustable sites. However, existing production methods are limited in terms of meeting the demanding challenges in achieving the scalable fabrication of high-quality nanomaterials under mild conditions. Here, we develop a facile intercalation–exfoliation method that can fabricate large lateral size (>23 µm) and few-layer LiInP₂S₆ nanosheets with high crystalline quality fast. Due to the advantage of hydrophilicity of lithium, swelled interlayer spacing can be obtained, which enables the rapid exfoliation by only slight manual shaking within tens of seconds. Concomitantly, the inorganic LiInP₂S₆ film manufactured by nanosheets has inter-connected ionic channels, which can be adjusted on the basis of the water content, enabling tunable ionic conductivity. As a result, ionic conductor films using ions as charge carriers can achieve high water response with good repeatability and excellent long-term stability in a wide moisture range. Moreover, the as-prepared detector has excellent capability in real-time noncontact human–machine interfacing. This study, not only is a powerful strategy for the fabrication of large-sized and high-quality nanosheets presented but also proof for the promising development of iontronic devices in new applications.

Microbial fuel cells (MFCs) benefit from the introduction of iron in the anode, as its multiple valence states and high electron-catalytic activity led to improved power densities in MFCs. However, the effect of long-term Fe³⁺ release into the electrolyte on the power density of MFCs is often overlooked. Herein, an anode consisting of a three-dimensional iron foam uniformly coated by reduced graphene oxide (rGO/IF) with a suitable loading density (8 g/m²) and a large specific surface area (0.05 m²/g) for high-density bacterial loading was prepared. The hybrid cells based on the rGO/IF anode exhibit a maximum power density of 5330 ± 76 mW/m² contributed by MFCs and galvanic cells. The rGO/IF anode enables continuous Fe³⁺ release for high electron-catalytic activity in the electrolyte during the discharging of the galvanic cells. As a result, the hybrid cells showed a power density of 2107 ± 64 mW/m² after four cycles, facilitated through reversible conversion between Fe³⁺ and Fe²⁺ in the electrolyte to accelerate electron transfer efficiency. The results indicate that the rGO/IF anode can be used for designing and fabricating high-power MFCs by optimizing the rate of release of Fe³⁺ in the electrolyte.

Conventional methods of stem cell therapy for tissue regeneration often face challenges, such as poor cell viability and integration posttransplantation. To address this, we proposed transplanting cells within synthetic microenvironments that maintain viability, cell phenotype, support extracellular matrix (ECM) secretion, and promote differentiation to enhance the regeneration of damaged host tissue. This hypothesis was tested in dental tissue regeneration using dental pulp stem cell-laden microcarriers (MCs) mixed in a gelatin methacrylate (GelMA) hydrogel as a delivery system. The combination of MCs and GelMA exhibited similar physical properties and favorable biological properties compared to GelMA alone. Specifically, cell-laden MC mixed into GelMA enhanced cell proliferation and ECM secretion and maintained a normal phenotype. Notably, MC-modified GelMA amplified odontogenic differentiation, mineralization, and vascular endothelial growth factor release. Moreover, the storage of MC-modified GelMA showed no detrimental effects on its injection force, cell viability, and mineralization potential, which demonstrates that the composite hydrogel is a promising injectable vehicle for therapeutic stem cell delivery. This strategy may be broadly applied to various tissues and organ systems, in which the provision and instruction of a cell population to participate in regeneration may be clinically useful.

Metal-organic frameworks (MOFs) are nanomaterials with engineered chemical structures, offering remarkable properties. However, their limited film-formation capability hinders their integration into triboelectric nanogenerators (TENGs). This study proposes a simple yet effective solution to overcome this challenge by employing electrospinning techniques to integrate the zeolitic imidazolate framework (ZIF-8) into an easy-to-use nanofibrous mat. ZIF-8 has high surface potential, a unique cubical structure, and an easy fabrication process that makes it an ideal material for TENGs. By incorporating ZIF-8 into the electrospinning solution, significant improvements are achieved in the electropositivity of the resulting nanofibers. It leads to notable changes in the shape, morphology, and roughness of electrospun fibers, consequently enhancing the overall performance of the TENG. The results indicate that utilizing the ZIF-based electrospun mat as a tribo-positive material can increase transferred charges between electrodes by more than 100%. Utilizing the MOF-based nanofibrous mat, this study also introduces a novel rotary TENG that works based on a mode of TENG operation called rolling mode. The reliable charge generation by the proposed rolling system reveals that this mode of TENG operation could be a superb alternative for traditional TENG modes, like contact/separation or sliding, which cause high levels of mechanical stress due to harsh physical impact or friction.

Continuous and quantitative monitoring of knee joint function has clinical value in rehabilitation assessment and the timing of return to play for anterior cruciate ligament injury patients. However, the existing approaches, including clinical examination, arthrometry and inertial solutions, can only be used for qualitative, off-line and low-quality evaluations, respectively. Burgeoning Kirigami stretchable sensors could be a disruptive candidate solution, but they usually suffer from structural buckling issues when used for large strain applications, such as knee joint motion capture where the buckling degrades sensor reliability and repeatability. Here, we propose a buckling-resistant stretchable and wearable sensor for knee joint motion capture. It enables continuous and precise motion signal capture of the knee joint and provides high wearing comfort and reliability. Clinical tests were conducted on 30 patients in the field, tracking data provided by the sensor from their initial hospitalization to later surgery. And the full rehabilitation of one subject was recorded and analyzed. The test results show that our sensor can dynamically assess knee function in real time and recommend the best timing for return to play, which paves the way for personalized and telerehabilitation.

Solution-processed fluorescent organic light-emitting diodes (OLEDs) are believed to be favorable for low-cost, large-area, and flexible displays but still suffer from the limited external quantum efficiency (EQE) below 5%. Herein, we demonstrate the EQE breakthrough by introducing a donor–acceptor type thermally activated delayed fluorescence (TADF) polymer as the sensitizer for the typical green-emitting fluorescent dopants. Benefitting from their matched energy alignment, the unwanted trap-assisted recombination directly on fluorescent dopant is prevented to avoid the additional loss of triplet excitons. Indeed, triplet excitons are mainly formed on the polymeric TADF sensitizer via a Langevin recombination and then spin-flipped to singlet excitons due to the good upconversion capability. Followed by an efficient Förster energy transfer, both singlet and triplet excitons can be harvested by fluorescent dopants, leading to a promising solution-processed green hyperfluorescence with a record-high EQE of 21.2% (72.2 cd/A, 59.7 lm/W) and Commission Internationale de L’Eclairage coordinates of (0.32, 0.59). The results clearly highlight the great potential of solution-processed fluorescent OLEDs based on TADF polymers as the sensitizer.

In integrated circuits (ICs), the parasitic capacitance is one of the crucial factors that degrade the circuit dynamic performance; for instance, it reduces the operating frequency of the circuit. Eliminating the parasitic capacitance in organic transistors is notoriously challenging due to the inherent tradeoff between manufacturing costs and interlayer alignment accuracy. Here, we overcome such a limitation using a cost-effective method for fabricating organic thin-film transistors and rectifying diodes without redundant electrode overlaps. This is achieved by placing all electrodes horizontally and introducing sub-100 nm gaps for separation. A representative small-scale IC consisting of five-stage ring oscillators based on the obtained nonparasitic transistors and diodes is fabricated on flexible substrates, which performs reliably at a low driving voltage of 1 V. Notably, the oscillator exhibits signal propagation delays of 5.8 µs per stage at a supply voltage of 20 V when utilizing pentacene as the active layer. Since parasitic capacitance has been a common challenge for all types of thin-film transistors, our approach may pave the way toward the realization of flexible and large-area ICs based on other emerging and highly performing semiconductors.

The vaccine is a premier healthcare intervention strategy in the battle against infectious infections. However, the development and production of vaccines present challenges in terms of complexity, cost, and time consumption. Alternative methodologies, such as nonthermal plasma and plant-based technologies, have emerged as potential alternatives for conventional vaccine manufacturing processes. While plasma-based approaches offer a rapid and efficient pathogen inactivation method devoid of harsh reagents, plant-based techniques present a more economically viable and scalable avenue for vaccine production. The imperative urges these approaches to address pressing global health challenges posed by emerging and recurring infectious diseases, surpassing the limitations of traditional vaccine fabrication methods. The primary goal of this review is to provide a comprehensive overview of the current research landscape, covering conceptualization, production, and potential advantages of plasma-based and plant-based vaccines. Furthermore, exploring the obstacles and opportunities intrinsic to these strategies is undertaken, elucidating their potential impact on vaccination strategies. This systematic presentation specifies a detailed outline of recent vaccine research and developments, emphasizing the possibility of advanced green approaches to produce effective and secure vaccination programs.

Liquid foams with tunable and photoresponsive stabilities and mechanical properties are highly desired in many domains, including the chemical and environmental protection industries. Here, we constructed photoresponsive liquid foams by structuring the interfacial adsorption layers and nanoparticle-embedded Plateau borders of the foam with biodegradable components. These foams exhibited ultrahigh foam stability but were easily destroyed by light, leading to a clean recovery of the liquid phase. In the absence of light, the hydroxypropyl cellulose (HPC) coils in the foam formed mechanically strong liquid films or “cohesive states.” Under irradiation, the ultrathin black phosphorus nanosheets induced changes in the packing parameters of the HPC assemblies within the Plateau borders and led to coil-to-globule transitions of the HPC and formed unstable liquid films with a “mobile state.” The two interfacial states were reversibly and repeatedly switched by turning the light on and off, which caused rapid bubble coalescence and foam collapse, and we also proved that this destabilizing mechanism was inhibited by cellulose nanocrystals. This work provides an environmentally friendly approach to controlling foam stability, and the proposed strategy can be expanded to the production of multiresponsive fully liquid objects in theory.

It is still a huge challenge to introduce effective crack-healing ability into energetic composites with a high oxidizer content. In this article, a poly(urea-urethane) energetic elastomer was prepared by the polycondensation reaction of glycidyl azido polymer (GAP), isophorone diisocyanate (IPDI), and 2-aminophenyl disulfide (2-APD). In the poly(urea-urethane) elastomer structure, the hybrid dynamic lock, including multilevel H-bonds and disulfide bonds, not only provides abundant dynamic interactions and promotes chain diffusion, but also enhances physical crosslinking density. Such a unique design fabricated the energetic elastomer with robust tensile strength (0.72 MPa), high stretchability (1631%), and outstanding toughness (8.95 MJ/m³) in the field of energetic polymers. Meanwhile, this energetic elastomer exhibited high self-healing efficiency (98.4% at 60 °C) and heat release (Q = 1750.46 J/g). Experimental and theoretical results adequately explain the self-healing mechanism, particularly the role of azido units. The high-solid content (80 wt%) energetic composites based on the energetic elastomer presented outstanding micro-defect self-healing (97.8%) and recycling without loss of mechanical performance. The development of smart energetic composites with excellent self-healing and recyclable ability provides a meaningful way for a wide range of applications in the field of energetic materials.

Exosomes, a specific subset of extracellular vesicles, have diverse functions in various biological processes. In the field of cancer research, there has been a growing interest in the potential of exosomes to act as versatile vehicles for targeted tumor imaging and therapy. In this study, we constructed a targeted delivery platform using hypoimmunogenic exosomes by genetically modifying β2-microglobulin knocking-out HEK-293F cells to express a fusion protein, referred to as αMUC1-Exo, which comprises the exosomal membrane-enriched platelet-derived growth factor receptor, intracellular nanoluciferase, and extracellular anti-MUC1 single-chain variable fragment. The findings of this study indicate that αMUC1-Exos exhibited notable drug delivery properties toward MUC1-positive pancreatic cancer cells, resulting in a substantial inhibition of tumor growth. Moreover, these exosomes demonstrated a high level of biosafety and the absence of any adverse effects. The application of engineered exosomes as a vehicle for drug delivery holds promise for enhancing the immunogenicity of neoplastic cells following treatment, thereby inducing antitumor immune memory in mice with intact immune systems, and also improving the response to anti-PD1 therapy. This approach utilizing engineered exosomes for Gemcitabine administration holds promise as a potential strategy for overcoming drug resistance in pancreatic carcinoma thereby improving the overall treatment efficacy.

Herein, an in situ approach of pulsed laser irradiation in liquids (PLIL) was exploited to create surface-modified electrodes for eco-friendly H₂ fuel production via electrolysis. The surface of the nickel foam (NF) substrate was nondestructively modified in 1.0 mol/L KOH using PLIL, resulting in a highly reactive Ni(OH)₂/NF. Moreover, single-metal Ir, Ru, and Pd nanoclusters were introduced onto Ni(OH)₂/NF via appropriate metal precursors. This simultaneous surface oxidation of the NF to Ni(OH)₂ and decoration with reduced metallic nanoparticles during PLIL are advantageous for promoting hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), and overall water splitting (OWS). The Ir-Ni(OH)₂/NF electrode demonstrates superior performance, achieving the lowest overpotentials at 10 mA/cm² (η) with 74 mV (HER) and 268 mV (OER). The OWS using Ir-Ni(OH)₂/NF||Ir-Ni(OH)₂/NF cell demonstrated a low voltage of 1.592 V, reaching 10 mA/cm² with notable stability of 72 h. Ir-Ni(OH)₂/NF performance is assigned to the improved defects and boosted intrinsic properties resulting from the synergy between metallic-nanoparticles and the oxidized NF surface, which are positively influenced by PLIL.

The sensory–neuromorphic interface is key to the application of neuromorphic electronics. Artificial spiking neurons and artificial sensory nerves have been created, and a few studies showed a complete neuromorphic system through cointegration with synaptic electronics. However, artificial synaptic devices and systems often do not work in real environments, which limits their ability to provide realistic neural simulations and interface with biological nerves. We report a sensory–neuromorphic interface that uses a fiber synapse to emulate a biological afferent nerve. For the first time, a sensing–neuromorphic interface is connected to a living organism for peripheral nerve stimulation, allowing the organism to establish a connection with its surrounding environment. The interface converts perceived environmental information into analog electrical signals and then into frequency-dependent pulse signals, which simplify the information interface between the sensor and the pulse-data processing center. The frequency of the interface shows a sublinear dependence on strain amplitude at different stimulus intensities, and can deliver increased frequency spikes at potentially damaging stimulus intensities, similar to the response of biological afferent nerves. To verify the application of this interface, a system that monitors strain and provides an overstrain alarm was constructed based on this afferent neural circuit. The system has a response time of <2 ms, which is compatible with the response time in biological systems. The interface can be potentially extended to process signals from almost any type of sensors for other afferent senses, and these results demonstrate the potential for neuromorphic interfaces to be applied to bionic sensory interfaces.