3D Printing‐Enabled Design and Manufacturing Strategies for Batteries: A Review

Lithium-ion batteries (LIBs) have significantly impacted the daily lives, finding broad applications in various industries such as consumer electronics, electric vehicles, medical devices, aerospace, and power tools. However, they still face issues (i.e., safety due to dendrite propagation, manufacturing cost, random porosities, and basic & planar geometries) that hinder their widespread applications as the demand for LIBs rapidly increases in all sectors due to their high energy and power density values compared to other batteries. Additive manufacturing (AM) is a promising technique for creating precise and programmable structures in energy storage devices. This review first summarizes light, filament, powder, and jetting-based 3D printing methods with the status on current trends and limitations for each AM technology. The paper also delves into 3D printing-enabled electrodes (both anodes and cathodes) and solid-state electrolytes for LIBs, emphasizing the current state-of-the-art materials, manufacturing methods, and properties/performance. Additionally, the current challenges in the AM for electrochemical energy storage (EES) applications, including limited materials, low processing precision, codesign/comanufacturing concepts for complete battery printing, machine learning (ML)/artificial intelligence (AI) for processing optimization and data analysis, environmental risks, and the potential of 4D printing in advanced battery applications, are also presented

Organoid technology and applications in cancer research

Abstract During the past decade, the three-dimensional organoid technology has sprung up and become more and more popular among researchers. Organoids are the miniatures of in vivo tissues and organs, and faithfully recapitulate the architectures and distinctive functions of a specific organ. These amazing three-dimensional constructs represent a promising, near-physiological model for human cancers, and tremendously support diverse potential applications in cancer research. Up to now, highly efficient establishment of organoids can be achieved from both normal and malignant tissues of patients. Using this bioengineered platform, the links of infection-cancer progression and mutation-carcinogenesis are feasible to be modeled. Another potential application is that organoid technology facilitates drug testing and guides personalized therapy. Although organoids still fail to model immune system accurately, co-cultures of organoids and lymphocytes have been reported in several studies, bringing hope for further application of this technology in immunotherapy. In addition, the potential value in regeneration medicine might be another paramount branch of organoid technology, which might refine current transplantation therapy through the replacement of irreversibly progressively diseased organs with isogenic healthy organoids. In conclusion, organoids represent an excellent preclinical model for human tumors, promoting the translation from basic cancer research to clinical practice. In this review, we outline organoid technology and summarize its applications in cancer research

PMMA-TiO2 Fibers for the Photocatalytic Degradation of Water Pollutants

Titanium dioxide (TiO2) is a promising photocatalyst that possesses a redox potential suitable for environmental remediation applications. A low photocatalytic yield and high cost have thus far limited the commercial adoption of TiO2-based fixed-bed reactors. One solution is to engineer the physical geometry or chemical composition of the substrate to overcome these limitations. In this work, porous polymethyl methacrylate (PMMA) substrates with immobilized TiO2 nanoparticles in fiber forms were fabricated and analyzed to demonstrate the influence of contaminant transport and light accessibility on the overall photocatalytic performance. The influences of (i) fiber porosity and (ii) fiber architecture on the overall photocatalytic performance were investigated. The porous structure was fabricated using wet phase inversion. The core-shell-structured fibers exhibited much higher mechanical properties than the porous fibers (7.52 GPa vs. non-testability) and maintained the same degradation rates as porous structures (0.059 vs. 0.053/min) in removing methylene blue with comparable specific surface areas. The highest methylene blue (MB) degradation rate (kMB) of 0.116 min−1 was observed due to increases of the exposed surface area, pointing to more efficient photocatalysis by optimizing core-shell dimensions. This research provides an easy-to-manufacture and cost-efficient method for producing PMMA/TiO2 core-shell fibers with a broad application in water treatment, air purification, and volatile sensors

Continuous Three-Dimensional Printing of Architected Piezoelectric Sensors in Minutes

Additive manufacturing (AM), also known as three-dimensional (3D) printing, is thriving as an effective and robust method in fabricating architected piezoelectric structures, yet most of the commonly adopted printing techniques often face the inherent speed-accuracy trade-off, limiting their speed in manufacturing sophisticated parts containing micro-/nanoscale features. Herein, stabilized, photo-curable resins comprising chemically functionalized piezoelectric nanoparticles (PiezoNPs) were formulated, from which microscale architected 3D piezoelectric structures were printed continuously via micro continuous liquid interface production (μCLIP) at speeds of up to ~60 μm s-1, which are more than 10 times faster than the previously reported stereolithography-based works. The 3D-printed functionalized barium titanate (f-BTO) composites reveal a bulk piezoelectric charge constant d33 of 27.70 pC N-1 with the 30 wt% f-BTO. Moreover, rationally designed lattice structures that manifested enhanced, tailorable piezoelectric sensing performance as well as mechanical flexibility were tested and explored in diverse flexible and wearable self-powered sensing applications, e.g., motion recognition and respiratory monitoring

Acupotomy Therapy for Knee Osteoarthritis Pain: Systematic Review and Meta-Analysis

Background and Purpose. Knee osteoarthritis (OA) is a major public health problem, and currently, few effective medical treatments exist. Chinese acupotomy therapy has been widely used for the treatment of knee OA in China. We conducted this systematic review and meta-analysis to evaluate the efficacy of Chinese acupotomy in treating knee OA to inform clinical practice. Methods. We performed a comprehensive search on PubMed, the Cochrane Library, EMBASE, and four Chinese databases for articles published prior to June 2020. We included only randomized controlled trials (RCTs) that used acupotomy therapy as the major intervention in adults with knee OA, were published in either Chinese and English, included more than 20 subjects in each group, and included pain and function in the outcome measures. Knee OA was defined by the American College of Rheumatology or Chinese Orthopedic Association criteria in all studies. We extracted the visual analogue scale (VAS) pain score, the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain score, the total effectiveness rate, the modified Japanese Orthopedic Association (JOA) activities of daily living score, and Lysholm’s score. We calculated the mean difference (MD) or risk ratio (RR) for all relevant outcomes. Meta-analyses were conducted using random-effects models when appropriate. Results. We identified 1317 potentially relevant studies, thirty-two of which met the eligibility criteria and were conducted in China between 2007 and 2020. A total of 3021 knee OA patients (62.96% female, median age: 57 years, and median disease duration: 33 months) were included. The treatment duration ranged from 1 week to 5 weeks (median: 3 weeks). The typical acupotomy treatment involved releasing soft tissue adhesions and was performed once a week for 1–5 weeks until the pain was relieved. The control group treatments included acupuncture (8 studies), electroacupuncture (10 studies), sodium hyaluronate (8 studies), radiofrequency electrotherapy (1 study), and nonsteroidal anti-inflammatory drugs (NSAIDs, 5 studies). The results from the meta-analysis showed that acupotomy led to superior improvements in the VAS pain score (MD = −1.11; 95% confidence interval (CI), −1.51 to −0.71; p < 0.00001) and WOMAC pain score (MD = −2.32; 95% CI, −2.94 to −1.69; p < 0.00001), a higher total effectiveness rate (RR = 1.15; 95% CI, 1.09–1.21; p < 0.00001), and superior improvements in the JOA score (MD = 6.39; 95% CI, 4.11–9.76; p < 0.00001) and Lysholm’s score (MD = 12.75; 95% CI, 2.61–22.89; p = 0.01) for overall pain and function. No serious adverse events were reported. Conclusion. Chinese acupotomy therapy may relieve pain and improve function in patients with knee OA. Furthermore, rigorously designed and well-controlled RCTs are warranted

Unveiling the failure mechanism on creep response of a casting Ni-based superalloy in thin-wall thickness

With the improvement of thermal efficiency and the lightweight tendency of engine blades, Ni-based superalloy is widely used owing to its excellent performance in high-temperature atmospheres. This work studied the effects of surface oxidation, internal environmental attack, and matrix damage on the failure mechanism in a thin-walled casting Ni-based superalloy at 980 °C/160 Mpa. At the edge of the fracture, the sample suffered a severe environmental attack, resulting in the oxidation-affected zone forms. However, the loss of effective bear area induced by surface damage could not be the main reason for the sample's failure. At the interior of the matrix, voids were preferably initiated at the interface of MC carbides. As the increase of creep deformation, dynamic recrystallization (DRX) occurred at the tip of the voids, which increased the transverse grain boundaries and promoted crack propagation. Moreover, the DRX provided a short penetration path for the nitrogen, causing internal nitridation with AlN and Ti(Ta)N to precipitate. EBSD analysis confirmed that nitrides induced significant dislocations to accumulate at the boundaries of nitrides/γ, accelerating the failure of the sample

Construction of ionic liquid-Pd/C based bifunction catalysts for the synthesis of UV-P

Adding light stabilizers to polymeric materials can inhibit or delay the light aging effect and improve the light resistance of materials. 2-(2′-Hydroxy-5′-methylphenyl) benzotriazole (UV-P), as a typical benzotriazole ultraviolet absorber, is widely used in various polymer synthetic materials and products owning to its outstanding oil resistance, color change resistance and low volatility. Currently, it is of great theoretical and practical significance to develop an environmentally friendly method to produce UV-P. Here, we introduce ionic liquids, tetra-butyl ammonium hydroxide, into the palladium-based catalyst, design a “transfer hydrogenation site - alkaline site” duel active center system, and investigate the physical and chemical properties and possible mechanism of this bifunction catalyst system. Such heterogeneous catalytic transfer hydrogenation method can remain 100% conversion and 93.86% selectivity. This bifunction catalyst also shows an outstanding stability when it was used for ten times, proving a green and efficient transfer hydrogenation method for the synthesis of UV-P

Crosslinked Polyethylene (XLPE), Recycling via Foams

International audienceEfficient recycling of crosslinked polyethylene has been challenging due to manufacturing difficulties caused by chemical crosslinking. This study focuses on simple processing via solid waste powder generation and particle fining for the subsequent crosslinked polyethylene inclusion and dispersion in rigid polyurethane foam. In addition, the concentration effects of crosslinked polyethylene in polyurethane were studied, showing a well-controlled foam microstructure with uniform pores, retained strength, better thermal degradation resistance, and, more importantly, increased thermal capabilities. Thus, the simple mechanical processing of crosslinked polyethylene and chemical urethane foaming showed the massive potential of recycling large amounts of crosslinked polyethylene in foams for broad applications in food packaging, house insulation, and sound reduction

Continuous Nanoparticle Patterning Strategy in Layer-Structured Nanocomposite Fibers

Anisotropic polymer/nanoparticle composites display unique mechanical, thermal, electrical, and optical properties depending on confirmation and configuration control of the composing elements. Processes, such as vapor deposition, ice-templating, nanoparticle self-assembly, additive manufacturing, or layer-by-layer casting, are explored to design and control nanoparticle microstructures with desired anisotropy or isotropy. However, limited attempts are made toward nanoparticle patterning during continuous fiber spinning due to the thin-diameter cross section and 1D features. Thus, this research focuses on a new patterning technique to form ordered nanoparticle assembly in layered composite fibers. As a result, distinct layers can be retained with innovative tool design, unique material combinations, and precise rheology control during fiber spinning. The layer multiplying-enabled nanoparticle patterning is demonstrated in a few material systems, including polyvinyl alcohol (PVA)-boron nitride (BN)/PVA, polyacrylonitrile (PAN)-aluminum (Al)/PAN, and PVA-BN/graphene nanoplatelet (GNP)/PVA systems. This approach demonstrates an unprecedentedly reported fiber manufacturing platform for well-managed layer dimensions and nanoparticle manipulations with directional thermal and electrical properties that can be utilized in broad applications, including structural supports, heat exchangers, electrical conductors, sensors, actuators, and soft robotics.W.X. and R.F. contributed equally to this work. This work was funded by the Global Sports Institute (GSI) at Arizona State University and the U.S. National Science Foundation (NSF, EAGER 1902172).Scopu