Multi-material 3D fabrication at the nanoscale has been a long-sought goal in additive manufacturing, with great potential for the direct construction of functional micro/nanosystems rather than just arbitrary 3D structures. To achieve this goal, researchers have introduced several nanoscale 3D printing principles, explored various multi-material switching and combination strategies, and demonstrated their potential applications in 3D integrated circuits, optoelectronics, biological devices, micro/nanorobots, etc. Although some progress has been made, it is still at the primary stage, and a serious breakthrough is needed to directly construct functional micro/nano systems. In this perspective, the development, current status and prospects of multi-material 3D nanoprinting are presented. We envision that this 3D printing will unlock innovative solutions and make significant contributions to various technologies and industries in the near future.

Significant advancements in ultra-precision machining technology have forced a re-examination of the spindle perpendicularity errors' impact on the milled surface quality at the micro-nano scale. In this paper, a method of spindle precision adjustment is proposed to enhance surface finish quality. Sensitive errors in the machining process are identified using multi-body kinematic theory, with the milling process serving as an example. A two-degree-of-freedom (2-DOF) rotation platform is designed, optimized, and fabricated. The platform's static model is established based on elastic beam theory and verified by finite element analysis. Structural parameters are optimized via the response surface method in combination with the Pareto front. Experimental results reveal the effects of spindle speed, voltage amplitude, vibration frequency, cutting depth, and feed rate on the platform's modulation performance. The static modulation experiment shows that the perpendicularity error between the spindle and the guideway can be reduced from 92.5 rad to 0.25 rad. Finally, milling experiments show that the surface quality can be improved by 37.6% after spindle modulation.

Integration of sensors with engineering thermoplastics allows to track their health and surrounding stimuli. As one of vital backbones to construct sensor systems, copper (Cu) is highly conductive and cost-effective, yet tends to easily oxidize during and after processing. Herein, an in-situ integrated sensor system on engineering thermoplastics via hybrid laser direct writing is proposed, which primarily consists of laser-passivated functional Cu interconnects and laser-induced carbon-based sensors. Through a one-step photothermal treatment, the resulting functional Cu interconnects after reductive sintering and passivation are capable of resisting long-term oxidation failure at high temperatures (up to 170 °C) without additional encapsulations. Interfacing with signal processing units, such an all-in-one system is applied for long-term and real-time temperature monitoring. This integrated sensor system with facile laser manufacturing strategies holds potentials for health monitoring and fault diagnosis of advanced equipment such as aircrafts, automobiles, high-speed trains, and medical devices.

Real-time physiological information monitoring can predict and prevent disease, or improve treatment by early diagnosis. A comprehensive and continuous monitoring of human health requires highly integrated wearable and comfortable sensing devices. To address this need, we propose a low-cost electronic fabric-enabled multifunctional flexible sensing integration platform that includes a flexible pressure sensor for monitoring postural pressure, a humidity sensor for monitoring the humidity of the skin surface, and a flexible temperature sensor for visualizing the ambient temperature around the human body. Thanks to the unique rough surface texture, hierarchical structure, and robust electromechanical features of the MXene-modified nonwoven fabrics, the flexible pressure sensor can achieve a monitoring sensitivity of 1529.1 kPa−1 and a pressure range of 150 kPa, which meets the demand for human pressure detection. In addition, the unique porous structure of the fabric and the stacked multilayer structure of MXene enable the humidity sensor to exhibit extremely high monitoring sensitivity, even through clothing, and still be able to detect the humidity on the skin surface. Temperature sensors based on screen-printed thermochromic liquid crystals enable visual monitoring in the range of 0 °C–65 °C. Through further integration with flexible printed circuit board circuits, we demonstrate a proof-of-concept device that enables real-time monitoring of human physiological information such as physical pressure, humidity, and ambient temperature environment, suggesting that the device provides an excellent platform for the development of commercially viable wearable healthcare monitors.

Traditional methods such as mechanical testing and x-ray computed tomography (CT), for quality assessment in laser powder-bed fusion (LPBF), a class of additive manufacturing (AM), are resource-intensive and conducted post-production. Recent advancements in in-situ monitoring, particularly using optical tomography (OT) to detect near-infrared light emissions during the process, offer an opportunity for in-situ defect detection. However, interpreting OT datasets remains challenging due to inherent process characteristics and disturbances that may obscure defect identification. This paper introduces a novel machine learning-based approach that integrates a self-organizing map, a fuzzy logic scheme, and a tailored U-Net architecture to enhance defect prediction capabilities during the LPBF process. This model not only predicts common flaws such as lack of fusion and keyhole defects through analysis of in-situ OT data, but also allows quality assurance professionals to apply their expert knowledge through customizable fuzzy rules. This capability facilitates a more nuanced and interpretable model, enhancing the likelihood of accurate defect detection. The efficacy of this system has been validated through experimental analyses across various process parameters, with results validated by subsequent CT scans, exhibiting strong performance with average model scores ranging from 0.375 to 0.819 for lack of fusion defects and from 0.391 to 0.616 for intentional keyhole defects. These findings underscore the model's reliability and adaptability in predicting defects, highlighting its potential as a transformative tool for in-process quality assurance in AM. A notable benefit of this method is its adaptability, allowing the end-user to adjust the probability threshold for defect detection based on desired quality requirements and custom fuzzy rules.

On-machine inspection has a significant impact on improving high-precision and efficient machining of sculptured surfaces. Due to the lack of machining information and the inability to adapt the parameters to the dynamic cutting conditions, theoretical modeling of profile inspection usually leads to insufficient adaptation, which causes inaccuracy problems. To address the above issues, a novel coupled model for profile inspection is proposed by combining the theoretical model and the data-driven model. The key process is to first realize local feature extraction based on the acquired vibration signals. The hybrid sampling model, which fuses geometric feature terms and vibration feature terms, is modeled by the lever principle. Then, the weight of each feature term is adaptively assigned by a multi-objective multi-verse optimizer. Finally, an inspection error compensation model based on the attention mechanism considering different probe postures is proposed to reduce the impact of pre-travel and radius errors on inspection accuracy. The anisotropy of the probe system error and its influence mechanism on the inspection accuracy are analyzed quantitatively and qualitatively. Compared with the previous models, the proposed hybrid profile inspection model can significantly improve the accuracy and efficiency of on-machine sampling. The proposed compensation model is able to correct the inspection errors with better accuracy. Simulations and experiments demonstrate the feasibility and validity of the proposed methods. The proposed model and corresponding new findings contribute to high-precision and efficient on-machine inspection, and help to understand the coupling mechanism of inspection errors.

The increasing demand for high-end equipment in crucial sectors such as aerospace, aeronautics, energy, power, information and electronics continues growing. However, the manufacturing of such advanced equipment poses significant challenges owing to high-level requirements for loading, transmission, conduction, energy conversion, and stealth. These challenges are amplified by complex structures, hard-to-cut materials, and strict standards for surface integrity and precision. To overcome these barriers in high-end equipment manufacturing, high-performance manufacturing (HPM) has emerged as an essential solution. This paper firstly discusses the key challenges in manufacturing technology and explores the essence of HPM, outlining a quantitative relationship between design and manufacturing. Subsequently, a generalized framework of HPM is proposed, accompanied by an in-depth exploration of the foundational elements and criteria. Ultimately, the feasible approaches and enabling technologies, supported by the analysis of two illustrative case studies are demonstrated. It is concluded that HPM is not just a precision and computational manufacturing framework with a core focus on multiparameter correlation in design, manufacturing, and service environments. It also represents a performance-geometry-integrated manufacturing framework for an accurate guarantee of the optimal performance.

Piezoelectric ultrasonic transducers have shown great potential in biomedical applications due to their high acoustic-to-electric conversion efficiency and large power capacity. The focusing technique enables the transducer to produce an extremely narrow beam, greatly improving the resolution and sensitivity. In this work, we summarize the fundamental properties and biological effects of the ultrasound field, aiming to establish a correlation between device design and application. Focusing techniques for piezoelectric transducers are highlighted, including material selection and fabrication methods, which determine the final performance of piezoelectric transducers. Numerous examples, from ultrasound imaging, neuromodulation, tumor ablation to ultrasonic wireless energy transfer, are summarized to highlight the great promise of biomedical applications. Finally, the challenges and opportunities of focused ultrasound transducers are presented. The aim of this review is to bridge the gap between focused ultrasound systems and biomedical applications.

Because of their high safety, low cost, and high volumetric specific capacity, zinc-ion batteries (ZIBs) are considered promising next-generation energy storage devices, especially given their high potential for large-scale energy storage. Despite these advantages, many problems remain for ZIBs—such as Zn dendrite growth, hydrogen evolution, and Zn anode corrosion—which significantly reduce the coulomb efficiency and reversibility of the battery and limit its cycle lifespan, resulting in much uncertainty in terms of its practical applications. Numerous electrolyte additives have been proposed in recent years to solve the aforementioned problems. This review focuses on electrolyte additives and discusses the different substances employed as additives to overcome the problems by altering the Zn2+ solvation structure, creating a protective layer at the anode–electrolyte interface, and modulating the Zn2+ distribution to be even and Zn deposition to be uniform. On the basis of the review, the possible research strategies, future directions of electrolyte additive development, and the existing problems to be solved are also described.

Triboelectric nanogenerators (TENGs) stand at the forefront of energy harvesting innovation, transforming mechanical energy into electrical power through triboelectrification and electrostatic induction. This groundbreaking technology addresses the urgent need for sustainable and renewable energy solutions, opening new avenues for self-powered systems. Despite their potential, TENGs face challenges such as material optimization for enhanced triboelectric effects, scalability, and improving conversion efficiency under varied conditions. Durability and environmental stability also pose significant hurdles, necessitating further research towards more resilient systems. Nature inspired TENG designs offer promising solutions by emulating biological processes and structures, such as the energy mechanisms of plants and the textured surfaces of animal skins. This biomimetic approach has led to notable improvements in material properties, structural designs, and overall TENG performance, including enhanced energy conversion efficiency and environmental robustness. The exploration into bio-inspired TENGs has unlocked new possibilities in energy harvesting, self-powered sensing, and wearable electronics, emphasizing reduced energy consumption and increased efficiency through innovative design. This review encapsulates the challenges and advancements in nature inspired TENGs, highlighting the integration of biomimetic principles to overcome current limitations. By focusing on augmented electrical properties, biodegradability, and self-healing capabilities, nature inspired TENGs pave the way for more sustainable and versatile energy solutions.

Sub-wavelength nanostructure lattices provide versatile platforms for light control and the basis for various novel phenomena and applications in physics, material science, chemistry, biology, and energy. The thriving study of nanostructure lattices is building on the remarkable progress of nanofabrication techniques, especially for the possibility of fabricating larger-area patterns while achieving higher-quality lattices, complex shapes, and hybrid materials units. In this review, we present a comprehensive review of techniques for large-area fabrication of optical nanostructure arrays, encompassing direct writing, self-assembly, controllable deposition, and nanoimprint/print methods. Furthermore, a particular focus is made on the recent improvement of unit accuracy and diversity, leading to integrated and multifunctional structures for devices and applications.

Soft (flexible and stretchable) biosensors have great potential in real-time and continuous health monitoring of various physiological factors, mainly due to their better conformability to soft human tissues and organs, which maximizes data fidelity and minimizes biological interference. Most of the early soft sensors focused on sensing physical signals. Recently, it is becoming a trend that novel soft sensors are developed to sense and monitor biochemical signals in situ in real biological environments, thus providing much more meaningful data for studying fundamental biology and diagnosing diverse health conditions. This is essential to decentralize the healthcare resources towards predictive medicine and better disease management. To meet the requirements of mechanical softness and complex biosensing, unconventional materials, and manufacturing process are demanded in developing biosensors. In this review, we summarize the fundamental approaches and the latest and representative design and fabrication to engineer soft electronics (flexible and stretchable) for wearable and implantable biochemical sensing. We will review the rational design and ingenious integration of stretchable materials, structures, and signal transducers in different application scenarios to fabricate high-performance soft biosensors. Focus is also given to how these novel biosensors can be integrated into diverse important physiological environments and scenarios in situ, such as sweat analysis, wound monitoring, and neurochemical sensing. We also rethink and discuss the current limitations, challenges, and prospects of soft biosensors. This review holds significant importance for researchers and engineers, as it assists in comprehending the overarching trends and pivotal issues within the realm of designing and manufacturing soft electronics for biochemical sensing.

Micro/nanorobots (MNRs) capable of performing tasks at the micro- and nanoscale hold great promise for applications in cutting-edge fields such as biomedical engineering, environmental engineering, and microfabrication. To cope with the intricate and dynamic environments encountered in practical applications, the development of high performance MNRs is crucial. They have evolved from single-material, single-function, and simple structure to multi-material, multi-function, and complex structure. However, the design and manufacturing of high performance MNRs with complex multi-material three-dimensional structures at the micro- and nanoscale pose significant challenges that cannot be addressed by conventional serial design strategies and single-process manufacturing methods. The material-interface-structure-function/performance coupled design methods and the additive/formative/subtractive composite manufacturing methods offer the opportunity to design and manufacture MNRs with multi-materials and complex structures under multi-factor coupling, thus paving the way for the development of high performance MNRs. In this paper, we take the three core capabilities of MNRs—mobility, controllability, and load capability—as the focal point, emphasizing the coupled design methods oriented towards their function/performance and the composite manufacturing methods for their functional structures. The limitations of current investigation are also discussed, and our envisioned future directions for design and manufacture of MNRs are shared. We hope that this review will provide a framework template for the design and manufacture of high performance MNRs, serving as a roadmap for researchers interested in this area.

High-bandwidth nano-positioning stages (NPSs) have boosted the advancement of modern ultra-precise, ultra-fast measurement and manufacturing technologies owing to their fast dynamic response, high stiffness and nanoscale resolution. However, the nonlinear actuation, lightly damped resonance and multi-axis cross-coupling effect bring significant challenges to the design, modeling and control of high-bandwidth NPSs. Consequently, numerous advanced works have been reported over the past decades to address these challenges. Here, this article provides a comprehensive review of high-bandwidth NPSs, which covers four representative aspects including mechanical design, system modeling, parameters optimization and high-bandwidth motion control. Besides, representative high-bandwidth NPSs applied to atomic force microscope and fast tool servo are highlighted. By providing an extensive overview of the design procedure for high-bandwidth NPSs, this review aims to offer a systemic solution for achieving operation with high speed, high accuracy and high resolution. Furthermore, remaining difficulties along with future developments in this fields are concluded and discussed.

Micro diamond tools are indispensable for the efficient machining of microstructured surfaces. The precision in tool manufacturing and cutting performance directly determines the processing quality of components. The manufacturing of high-quality micro diamond tools relies on scientific design methods and appropriate processing techniques. However, there is currently a lack of systematic review on the design and manufacturing methods of micro diamond tools in academia. This study systematically summarizes and analyzes modern manufacturing methods for micro diamond tools, as well as the impact of tool waviness, sharpness, and durability on machining quality. Subsequently, a design method is proposed based on the theory of cutting edge strength distribution to enhance tool waviness, sharpness, and durability. Finally, this paper presents current technical challenges faced by micro diamond tools along with potential future solutions to guide scientists in this field. The aim of this review is to contribute to the further development of the current design and manufacturing processes for micro diamond cutting tools.

The ocean is the largest reservoir of renewable energy on earth, in which wave energy occupies an important position due to its high energy density and extensive distribution. As a cutting-edge technology, wave-driven triboelectric nanogenerators (W-TENGs) demonstrate substantial potential for ocean energy conversion and utilization. This paper provides a comprehensive review of W-TENGs, from materials manufacturing and structural fabrications to marine applications. It highlights the versatility in materials selection for W-TENGs and the potential for unique treatments to enhance output performance. With the development of materials science, researchers can manufacture materials with various properties as needed. The structural design and fabrication of W-TENGs is the pillar of converting wave energy to electrical energy. The flexible combination of TENG's multiple working modes and advanced manufacturing methods make W-TENGs' structures rich and diverse. Advanced technologies, such as three-dimensional printing, make manufacturing and upgrading W-TENGs more convenient and efficient. This paper summarizes their structures and elucidates their features and manufacturing processes. It should be noted that all efforts made in materials and structures are aimed at W-TENGs, having a bright application prospect. The latest studies on W-TENGs for effective application in the marine field are reviewed, and their feasibility and practical value are evaluated. Finally, based on a systematic review, the existing challenges at this stage are pointed out. More importantly, strategies to address these challenges and directions for future research efforts are also discussed. This review aims to clarify the recent advances in standardization and scale-up of W-TENGs to promote richer innovation and practice in the future.

Ta-based materials have gained significant interest for bioimplantable scaffolds because of their appropriate mechanical characteristics and biocompatibility. To overcome the serious limitation of bioinertness, there have been many efforts to enhance the bioactivity and osseointegration of Ta-based scaffolds through morphostructural and surface modifications. As scaffolds are implantable devices, sufficient bioactivity is needed to trigger the cellular functions required for tissue engineering. Consequently, a combination of materials and bioscience is needed to develop efficient Ta-based scaffolds, although reviews of this interdisciplinary field remain limited. This review aims to provide an overview of the main strategies to enhance the bioactivity of Ta-based scaffolds, describing the basic mechanisms and research methods of osseointegration, and the approaches to enhance bioactivity and osseointegration. These approaches are divided into three main sections: (i) alteration of the micromorphology, (ii) customization of the scaffold structure, and (iii) functionalization modifications (through alloying or the addition of surface coatings). Also provided are recent advances regarding biocompatibility assessment in vitro, osseointegration properties in vivo, and clinical trial results.

Four-dimensional (4D) printing is regarded as a methodology that links 3D printing to time, which is characterized by the evolution of predetermined structures or functions for the printed object after applying stimulation. This dynamic feature endows 4D printing the potential to be intelligent, attracting wide attention from academia and industry. The transformation of shape and function is both obtained from the programming of the object endowed by the intrinsic characteristics of the material or by the manufacturing technology. Therefore, it is necessary to understand 4D printing from the perspective of both mechanism and manufacturing. Here, the state-of-the-art 4D printing polymer was summarized, beginning with the classifications, and leading to the mechanisms, stimulations, and technologies. The links and differences between 4D printing polymer and shape memory polymer, between 4D printing and 3D printing were highlighted. Finally, the biomedical applications were outlined and the perspectives were discussed.

Aero-engines, the core of air travel, rely on advanced high strength-toughness alloys (THSAs) such as titanium alloys, nickel-based superalloys, intermetallics, and ultra-high strength steel. The precision of cutting techniques is crucial for the manufacture of key components, including blades, discs, shafts, and gears. However, machining THSAs pose significant challenges, including high cutting forces and temperatures, which lead to rapid tool wear, reduced efficiency, and compromised surface integrity. This review thoroughly explores the current landscape and future directions of cutting techniques for THSAs in aero-engines. It examines the principles, mechanisms, and benefits of energy-assisted cutting technologies like laser-assisted machining and cryogenic cooling. The review assesses various tool preparation methods, their effects on tool performance, and strategies for precise shape and surface integrity control. It also outlines intelligent monitoring technologies for machining process status, covering aspects such as tool wear, surface roughness, and chatter, contributing to intelligent manufacturing. Additionally, it highlights emerging trends and potential future developments, including multi-energy assisted cutting mechanisms, advanced cutting tools, and collaborative control of structure shape and surface integrity, alongside intelligent monitoring software and hardware. This review serves as a reference for achieving efficient and high-quality manufacturing of THSAs in aero-engines.

The capability for synergistic advancements in both making and shaping afforded by additive manufacturing (AM) enables the flexible production of high-performance components. Boosted by the growing demand for heat-resistant aluminum alloys in the moderate-temperature weight-critical applications, AM of heat-resistant aluminum alloys constitutes a burgeoning field. Although numerous advances have emerged in recent years, there remains a gap in the review literature elucidating the newly-developed alloy systems and critically evaluating the efficacy. This state-of-the-art review presents a detailed overview of recent achievements on the heat-resistant aluminum alloy development. It begins with the introduction of various AM technologies and the pros and cons of each technique are evaluated. The enhancement mechanisms associated with printability and high-temperature properties of AM aluminum alloys are then delineated. Thereafter, the various additively manufactured aluminum alloy systems are discussed with regard to the microstructure, heat resistance and high-temperature performance. An emphasis is put on the powder bed fusion-laser beam (PBF-LB) as it has garnered significant attention for heat-resistant aluminum alloys and the vast majority of the current studies are based on this technique. Finally, perspectives are outlined to provide guidance for future research.