bluuebunny/crossref_metadata_2025 huggingface dataset:
0D/1D Heterojunction Implant with Electro‐Mechanobiological Coupling Cues Promotes Osteogenesis
Authors: Huang Xiao , Xing Jun , Wang Zhengao , Han Jin , Wang Renxian , Li Changhao , Xiao Cairong , Lu Fang , Zhai Jinxia , Zhou Zhengnan , Li Yangfan , Zhou Lei , Song Zhiguo , Chen Dafu , Yu Peng , Ning Chengyun , Jiang Xieyuan
Published: September 2021

Mimicking the natural bone extracellular matrix containing intrinsic topography and electrical signals is an effective way to modulate bone regeneration. However, simultaneously coupling of the intrinsic mechanobiology and electrical cues of implant to modulate bone regeneration remains ignored. Here, the authors report in situ designation of titanium dioxide (TiO2) nanocone/bismuth oxide (Bi2O3) nanodot heterojunctions on bone implant surface to electro‐biomechanically trigger osseointegration at bone/implant interface. TiO2 nanocone/Bi2O3 nanodot heterojunctions exhibit built‐in electric field at the nanoscale interface and elastic modulus equivalent to that of bone tissue. The nano‐heterojunctions significantly promoted the attachment, spreading, and osteogenic differentiation of bone marrow mesenchymal stem cells in vitro, and the osteogenesis in vivo. The authors also show that the effects of nano‐heterojunctions on osteogenesis are mediated by yes‐associated protein biomechanical signal pathway and intracellular enrichment induced Phosphatidylinositol 3‐kinase signal pathway. Their findings highlight the coupling of topographical and electric parameters of biomaterials for modulating cell behaviors.
Pro‐Healing Zwitterionic Skin Sensor Enables Multi‐Indicator Distinction and Continuous Real‐Time Monitoring
Authors: Guo Hongshuang , Bai Ming , Zhu Yingnan , Liu Xinmeng , Tian Shu , Long You , Ma Yiming , Wen Chiyu , Li Qingsi , Yang Jing , Zhang Lei
Published: September 2021

In both artificial electronic and ionic skins, the distinction of multi‐stimuli response in a single sensing unit is challenging, due to unavoidable mutual signal interference. Here, a zwitterionic skin sensor system that can continuously monitor and differentiate three‐stimuli‐responsive information in real‐time is designed. This sandwich‐structured sensor system is based on a zwitterionic thermo–glucose‐sensitive skin‐like hydrogel at its upper and lower layers with a middle isolation elastomer layer, enabling monitoring and distinction of temperature, mechanical and glucose information without signal interference: 1) the capacitance of the upper/lower layers as glucose–temperature‐insensitive is variable to measure strain; 2) the resistance of the upper hydrogel as glucose‐insensitive is variable to measure strain and temperature; and 3) the resistance of the lower hydrogel can detect three indicators. Based on the skin sensor system, a smart wound dressing is developed to pro‐heal chronic diabetic wounds and enable continuous real‐time monitoring of three indicators—infection, swelling, and blood glucose. This work provides a new method of real‐time monitoring and the distinction of multi‐stimuli response in a wearable device.
A Textile‐Based Temperature‐Tolerant Stretchable Supercapacitor for Wearable Electronics
Authors: Lee Hanchan , Jung Gyusung , Keum Kayeon , Kim Jung Wook , Jeong Hyein , Lee Yong Hui , Kim Dong Sik , Ha Jeong Sook
Published: September 2021

Among the extensive development of wearable electronics, which can be implanted onto bodies or embedded in clothes, textile‐based devices have gained significant attention. For daily basis applications, wearable energy storage devices are required to be stable under harsh environmental conditions and different deformational conditions. In this study, a textile‐based stretchable supercapacitor with high electrochemical performance, mechanical stability, and temperature tolerance over a wide temperature range is reported. It exhibits high areal capacitances of 28.0, 30.4, and 30.6 mF cm−2 at −30, 25, and 80 °C, respectively, while the capacitance remains stable over three repeated cycles of cooling and heating from −30 to 80 °C. The supercapacitor is stable under stretching up to 50% and 1000 repetitive cycles of stretching. A temperature sensor and an liquid‐crystal display are simultaneously driven at temperatures between −20 and 80 °C by the supercapacitors. The supercapacitors are woven into a nylon glove power a micro‐light‐emitting diode stably regardless of the bending of the index finger. Furthermore, the encapsulated supercapacitors retain the capacitance during being immersed in water for a few days. This study demonstrates the potential application of the fabricated supercapacitor as a wearable energy storage device that works under extreme temperature variations, high humidity, and body movements.
Multistage Responsive Materials for Real‐time, Reversible, and Sustainable Light‐Writing
Authors: Liu Jize , Guo Quanquan , Zhang Xinxing , Gai Jinggang , Zhang Chuhong
Published: September 2021

Stimulus‐responsive materials with designable integrated functions bridge the intelligent systems in future lifestyles with the Internet of Things (IoT). The growing trend for IoT and corresponding advanced devices will involve a great number of electronic disposables, which may place heavy burdens on the environment. Here, an elaborately designed multistage responsive material is reported for real‐time, reversible light‐writing based on organized stage‐by‐stage responsive behaviors and polarity‐dependent physicochemical fluorescence response, where the stimulus is accurately delivered through a completely reversible “light‐heat‐fluorescence” pathway. The resulted materials can be pollution‐freely written by hand‐controlled near‐infrared laser within 5 s, spontaneously erased within 20 s, and exhibit excellent re‐writing ability (more than 5000 times while the variance of chromaticity coordinates <0.0008), which is difficult to achieve by traditional laser writing technologies. This study is a step toward high‐performance long‐life functional devices based on reversible multistage responsive materials for future IoT lifestyles.
Noble‐Metal‐Assisted Fast Interfacial Oxygen Migration with Topotactic Phase Transition in Perovskite Oxides
Authors: Wang Qian , Gu Youdi , Zhu Wenxuan , Han Lei , Pan Feng , Song Cheng
Published: September 2021

Transition‐metal perovskite oxides constitute a series of functional material systems for electronics, catalysis, and energy‐conversion processes, in which oxygen migration and evolution play a key role. However, the stable metal–oxygen (MO) bond forms a large energy barrier inhibiting ion diffusion. Therefore, seeking efficient and facile approaches to accelerate oxygen kinetics has become a significant issue. Here, the interaction (interfacial charge transfer and cooperative bonding) between noble metal (Pt, Ag) and perovskites oxide (SrCoO3−δ) is employed to weaken the (MO) bond and decrease the energy barrier of oxygen migration. Noble metal layers serving as oxygen pumps can continuously extract oxygen from oxide films to the atmosphere. The temperature of the topotactic phase transition from perovskite (SrCoO3) to brownmillerite (SrCoO2.5) is remarkably lowered from ≈200 °C to room temperature. Furthermore, this approach can also be applied to SrFeO3 for similar topotactic phase reduction by moderate thermal activation. The finding of this study paves a promising and general pathway to achieve fast oxygen migration in perovskite oxides, with important application prospects in low‐temperature electrodes and high‐activity catalysis interface.
DLP 4D‐Printing of Remotely, Modularly, and Selectively Controllable Shape Memory Polymer Nanocomposites Embedding Carbon Nanotubes
Authors: Cortés Alejandro , Cosola Andrea , Sangermano Marco , Campo Mónica , González Prolongo Silvia , Pirri Candido Fabrizio , Jiménez‐Suárez Alberto , Chiappone Annalisa
Published: September 2021

An in‐depth investigation on novel electro‐activated shape memory polymer composites (SMPCs) for digital light processing 3D‐Printing, consisting of a poly(ethylene glycol) diacrylate/poly(hydroxyethyl methacrylate) matrix embedding multi‐walled carbon nanotubes (CNTs), is reported here. The composition of the photocurable (meth)acrylate system is finely tuned to tailor the thermomechanical properties of the matrix, whereas the effect of CNTs on the photoreactivity and rheological properties of the formulations is investigated to assess the printability. Electrical measurements confirmed that the incorporation of CNT into the polymeric matrix enables the electrical conductivity and thus the possibility to remotely heat the nanocomposite using the Joule effect. The feasibility to drive a shape memory cycle via Joule heating is proved, given that the high shape fixity (Rf) and shape recovery (Rr) ratios achieved (Rf ≈ 100%,Rr > 95%) confirmed the significant electrically‐triggered responsiveness of such CNT/SMPCs. Finally, it is shown how to activate a modular and selective electro‐activated shape recovery, which may ultimately envisage the 4D‐Printing of remotely and selectively controllable smart devices.
CRISPR/Cas9‐2D Silicene Gene‐Editing Nanosystem for Remote NIR‐II‐Induced Tumor Microenvironment Reprogramming and Augmented Photonic Tumor Ablation
Authors: Yin Haohao , Zhou Bangguo , Dong Caihong , Zhang Yan , Yu Jifeng , Pu Yinying , Feng Wei , Sun Liping , Hu Hui , Chen Yu , Xu Huixiong
Published: September 2021

Photothermal therapy (PTT) is a minimally invasive and highly specific antineoplastic treatment, whereas the significant upregulation of TXNDC5 gene expression following PTT cripples the photothermal ablation efficacy through protein processing in the endoplasmic reticulum signaling pathway, as transcriptome sequencing and bioinformatics analysis revealed in this research. To tackle this crucial issue, a second near‐infrared biowindow (NIR‐II) light‐controlled CRISPR/Cas9 nanosystem (silicene‐Cas9) is constructed based on biosafe and biodegradable 2D silicene nanosheets with desirable photothermal‐conversion capability. The elaborate system enables remote NIR‐II‐induced reprogramming of tumor microenvironment for enhanced photonic tumor ablation. Moreover, this CRISPR/Cas9 delivery system is carried out to precisely and efficiently knock down TXNDC5 for reprogramming the tumor microenvironment and amplifying the photothermal performance of silicene, exhibiting high efficiency and controlled gene‐editing capacity of 47.68% and significantly improving therapeutic effect of tumor ablation without recurrence both in vitro and in vivo. This work not only provides a paradigm of improving the effectiveness of photothermal tumor therapy, but also develops a safe and efficient 2D silicene‐based nonviral vector for harnessing CRISPSR/Cas9 technology‐mediated genome editing, which further broadens the biomedical application of 2D silicene nanosheets.
Wide Working Temperature Range Rechargeable Lithium–Sulfur Batteries: A Critical Review
Authors: Zhou Zhenfang , Li Guicun , Zhang Jiujun , Zhao Yufeng
Published: September 2021

At the technological forefront of energy storage, there is still a continuous upsurge in demand for high energy and power density batteries that can operate at a wide range of temperature. Rechargeable lithium sulfur batteries stand out among other advanced cell concepts owing to their ultrahigh theoretical gravimetric energy density characteristic as well as merits of low cost and environmental friendliness. Although achieving good operability of ambient lithium sulfur batteries, extending their workability to both higher and lower temperatures is also of paramount importance especially for future task‐specific applications. As a first attempt, this review presents a comprehensive understanding on the advances, challenges, and future research directions on lithium sulfur batteries operating at both low and high temperature extremes. From a material perspective, the workability of sulfur‐containing cathode materials, advanced electrolytes (from conventional liquid to quasi‐ and all‐solid‐state electrolytes), lithium metal anodes and the electrochemically inert components (separators and interlayer materials) at extreme temperatures are thoroughly analyzed. The insurmountable challenges and mechanistic understandings caused by thermal changes are critically reviewed. Finally, potential future research directions and prospects for lithium sulfur batteries operated at a wide range of temperature are also proposed.
3D Wearable Fabric‐Based Micro‐Supercapacitors with Ultra‐High Areal Capacitance
Authors: Li Dongdong , Yang Sheng , Chen Xin , Lai Wen‐Yong , Huang Wei
Published: September 2021

Miniaturized electronics require integrated unit configuration in very limited space, where energy storage per unit area is thus extremely critical. Micro‐supercapacitors (MSCs), mainly established on planar substrates, are superior but still suffer from limited areal capacitance. Herein, a novel strategy is introduced to construct high cross‐section MSCs using 3D fabrics as the porous skeleton. Interdigitated poly(3,4‐ethylenedioxythiophene): poly(styrenesulfonate) (PEDOT:PSS) is patterned on 3D fabrics to achieve continuous conductive networks, while MnO2 microspheres epitaxially grown on PEDOT:PSS are fully exposed to electrolyte with the support of fabric fibers. The unique architecture can utilize more active sites of thick electrodes and the high conductivity of interpenetrating fiber networks. The resulting fabric‐based MSCs demonstrate ultra‐high areal capacitance of 135.4 mF cm−2, which is 3.5 times that of devices on polyethylene terephthalate substrates and is among the highest values for planar‐based MSCs using the same interdigital geometry. Moreover, the flexible fabrics endow MSCs with extremely high bending stability with 94% capacitance retention even after 3000 cycles. These figures‐of‐merit enable fabric‐based MSCs promising to be used in the next‐generation of wearable electronics.
Immune Cycle‐Based Strategies for Cancer Immunotherapy
Authors: Li Yanhua , Liu Xiaohan , Zhang Xia , Pan Wei , Li Na , Tang Bo
Published: September 2021

The immune system is composed of immune organs, immune cells, and immunoactive substances, which plays a vital role in antitumor immunity in cancer immunotherapy. During the process of the antitumor immune response, many factors are involved in the cancer immune cycle. Therefore, developing intelligent strategies based on the steps of the cancer immune cycle to elicit the immune responses for enhanced cancer immunotherapy is of great significance. In this review, the key factors in each step of the cancer immune cycle are discussed, and then, the intelligent therapeutic strategies for modulating the immune surveillance against cancer are highlighted. Considering the demand for cancer immunotherapy in clinic, some suggestions for constructing new intelligent strategies are also put forward, which will make antitumor immunity more effective and advance the development of cancer immunotherapy.
Substrate‐Independent and Re‐Writable Surface Patterning by Combining Polydopamine Coatings, Silanization, and Thiol‐Ene Reaction
Authors: Li Shuai , Scheiger Johannes M. , Wang Zhenwu , Dong Zheqin , Welle Alexander , Trouillet Vanessa , Levkin Pavel A.
Published: September 2021

Polydopamine coating is a unique, simple, and substrate‐independent surface functionalization strategy. Techniques for secondary functionalization, patterning, and re‐functionalization of polydopamine modified materials are important to broaden the scope of applications of such materials in a variety of fields. Here, a facile and substrate‐independent strategy for surface functionalization and patterning is presented. This approach combines the advantages of three important methods: facile and substrate‐independent polydopamine coating, versatile gas phase silanization, and rapid thiol‐ene photoclick reaction for patterning. They demonstrate equally efficient functionalization and patterning of diverse materials, such as glass, polytetrafluoroethylene, aluminum, polypropylene, or polyethylene. They also show the possibility of controlled chemical removal of the patterns or surface functionalization by treatment with tetrabutylammonium fluoride, which allows re‐modification or re‐patterning of the substrate. Thus, this universal and powerful approach for substrate independent surface modification and patterning can significantly facilitate the development of novel functional materials and devices useful for various applications.
Superior Rate Mesoporous Carbon Sphere Array Composite via Intercalation and Conversion Coupling Mechanisms for Potassium‐Ion Capacitors
Authors: Liu Hongxin , Zhang Wulin , Song Yan , Li Lanlan , Zhang Chengwei , Wang Gongkai
Published: September 2021

Carbonaceous materials have been usually adopted as the anode for high energy density potassium‐ion hybrid capacitors (KICs) owing to their low voltage plateau, high conductivity, and excellent electrochemical compatibility. The improvements of their specific capacity and sluggish intercalation mechanism are still challenges to further boost the energy density of KICs while maintaining high power density and long cycle life. Herein, a N‐doped mesoporous carbon sphere array composite is developed by a dual‐templates method. The N‐doped carbon sphere array with interpenetrated macro‐ and meso‐pores facilitates the fast electron transport and rapid K+ diffusion. The uniformly introduced Co3O4 nanoparticles (NPs) confined in the array enable a kinetically boosted conversion reaction for excess and fast K+ storage. The partially oxidized Co NPs can efficiently enhance the conductivity of the entire composite. By introducing this optimized conversion capacity from encapsulated Co3O4 NPs, the composite with intercalation and conversion coupling mechanisms displays superior capacity and cycle life. The assembled KICs exhibit high energy/power densities (148 Wh kg−1/124 W kg−1) and great cycling performance (94% after 5000 cycles, 0.5 A g−1). This promising strategy demonstrates an example for carbonaceous composite anode with synergistic K+ storage hybrid mechanism toward high performance KICs.
The Importance of Interfaces in Multi‐Material Biofabricated Tissue Structures
Authors: Viola Martina , Piluso Susanna , Groll Jürgen , Vermonden Tina , Malda Jos , Castilho Miguel
Published: September 2021

Biofabrication exploits additive manufacturing techniques for creating 3D structures with a precise geometry that aim to mimic a physiological cellular environment and to develop the growth of native tissues. The most recent approaches of 3D biofabrication integrate multiple technologies into a single biofabrication platform combining different materials within different length scales to achieve improved construct functionality. However, the importance of interfaces between the different material phases, has not been adequately explored. This is known to determine material's interaction and ultimately mechanical and biological performance of biofabricated parts. In this review, this gap is bridged by critically examining the interface between different material phases in (bio)fabricated structures, with a particular focus on how interfacial interactions can compromise or define the mechanical (and biological) properties of the engineered structures. It is believed that the importance of interfacial properties between the different constituents of a composite material, deserves particular attention in its role in modulating the final characteristics of 3D tissue‐like structures.
Tattoo Inks for Optical Biosensing in Interstitial Fluid
Authors: Pazos Martalu D. , Hu Yubing , Elani Yuval , Browning Kathryn L. , Jiang Nan , Yetisen Ali K.
Published: September 2021

The persistence of traditional tattoo inks presents an advantage for continuous and long‐term health monitoring in point of care devices. The replacement of tattoo pigments with optical biosensors aims a promising alternative for monitoring blood biomarkers. Tattoo inks functionalization enables the control of interstitial biomarkers with correlated concentrations in plasma, to diagnose diseases, evaluate progression, and prevent complications associated with physio pathological disorders or medication mismatches. The specific biomarkers in interstitial fluid provide a new source of information, especially for skin diseases. The study of tattoo inks displays insufficient regulation in their composition, a lack of reports of the related complications, and a need for further studies on their degradation kinetics. This review focuses on tattoo optical biosensors for monitoring dermal interstitial biomarkers and discusses the clinical advantages and main challenges for in vivo implantation. Tattoo functionalization provides a minimally invasive, reversible, biocompatible, real‐time sensing with long‐term permanence and multiplexing capabilities for the control, diagnosis, and prevention of illness; it enables self‐controlling management by the patient, but also the possibility of sending the records to the doctor.
Stem/Proliferative and Differentiated Cells within Primary Murine Colonic Epithelium Display Distinct Intracellular Free Ca2+ Signal Codes
Authors: Mestril Sebastian , Kim Raehyun , Hinman Samuel S. , Gomez Shawn M. , Allbritton Nancy L.
Published: September 2021

The second messenger, intracellular free calcium (Ca2+), acts to transduce mitogenic and differentiation signals incoming to the colonic epithelium. A self‐renewing monolayer of primary murine colonic epithelial cells is formed over a soft, transparent hydrogel matrix for the scalable analysis of intracellular Ca2+ transients. Cultures that are enriched for stem/proliferative cells exhibit repetitive, high frequency (≈25 peaks h−1), and short pulse width (≈25 s) Ca2+ transients. Upon cell differentiation the transient frequency declines by 50% and pulse width widens by 200%. Metabolites and growth factors that are known to modulate stem cell proliferation and differentiation through Wnt and Notch signaling pathways, including CHIR‐99021, N‐[(3,5‐Difluorophenyl)acetyl]‐L‐alanyl‐2‐phenylglycine‐1,1‐dimethylethyl ester (DAPT), bone morphogenetic proteins (BMPs), and butyrate, also modulate Ca2+ oscillation patterns in a consistent manner. Increasing the stiffness of the supportive matrix from 200 Pa to 3 GPa shifts Ca2+ transient patterns toward those resembling differentiated cells. The ability to monitor Ca2+ oscillations with the spatial and temporal resolution offered by this platform, combined with its amenability to high‐content screens, provides a powerful tool for investigating real‐time communication within a wide range of primary tissues in addition to the colonic epithelium.
Mito‐Bomb: Targeting Mitochondria for Cancer Therapy
Authors: Guo Xiaolu , Yang Naidi , Ji Wenhui , Zhang Hang , Dong Xiao , Zhou Zhiqiang , Li Lin , Shen Han‐Ming , Yao Shao Q. , Huang Wei
Published: September 2021

Cancer has been one of the most common life‐threatening diseases for a long time. Traditional cancer therapies such as surgery, chemotherapy (CT), and radiotherapy (RT) have limited effects due to drug resistance, unsatisfactory treatment efficiency, and side effects. In recent years, photodynamic therapy (PDT), photothermal therapy (PTT), and chemodynamic therapy (CDT) have been utilized for cancer treatment owing to their high selectivity, minor resistance, and minimal toxicity. Accumulating evidence has demonstrated that selective delivery of drugs to specific subcellular organelles can significantly enhance the efficiency of cancer therapy. Mitochondria‐targeting therapeutic strategies are promising for cancer therapy, which is attributed to the essential role of mitochondria in the regulation of cancer cell apoptosis, metabolism, and more vulnerable to hyperthermia and oxidative damage. Herein, the rational design, functionalization, and applications of diverse mitochondria‐targeting units, involving organic phosphine/sulfur salts, quaternary ammonium (QA) salts, peptides, transition‐metal complexes, guanidinium or bisguanidinium, as well as mitochondria‐targeting cancer therapies including PDT, PTT, CDT, and others are summarized. This review aims to furnish researchers with deep insights and hints in the design and applications of novel mitochondria‐targeting agents for cancer therapy.
The Food–Materials Nexus: Next Generation Bioplastics and Advanced Materials from Agri‐Food Residues
Authors: Otoni Caio G. , Azeredo Henriette M. C. , Mattos Bruno D. , Beaumont Marco , Correa Daniel S. , Rojas Orlando J.
Published: September 2021

The most recent strategies available for upcycling agri‐food losses and waste (FLW) into functional bioplastics and advanced materials are reviewed and the valorization of food residuals are put in perspective, adding to the water–food–energy nexus. Low value or underutilized biomass, biocolloids, water‐soluble biopolymers, polymerizable monomers, and nutrients are introduced as feasible building blocks for biotechnological conversion into bioplastics. The latter are demonstrated for their incorporation in multifunctional packaging, biomedical devices, sensors, actuators, and energy conversion and storage devices, contributing to the valorization efforts within the future circular bioeconomy. Strategies are introduced to effectively synthesize, deconstruct and reassemble or engineer FLW‐derived monomeric, polymeric, and colloidal building blocks. Multifunctional bioplastics are introduced considering the structural, chemical, physical as well as the accessibility of FLW precursors. Processing techniques are analyzed within the fields of polymer chemistry and physics. The prospects of FLW streams and biomass surplus, considering their availability, interactions with water and thermal stability, are critically discussed in a near‐future scenario that is expected to lead to next‐generation bioplastics and advanced materials.
Chaotic Organic Crystal Phosphorescent Patterns for Physical Unclonable Functions
Authors: Im Healin , Yoon Jinsik , Choi Jinho , Kim Jinsang , Baek Seungho , Park Dong Hyuk , Park Wook , Kim Sunkook
Published: September 2021

Since the 4th Industrial Revolution, Internet of Things based environments have been widely used in various fields ranging from mobile to medical devices. Simultaneously, information leakage and hacking risks have also increased significantly, and secure authentication and security systems are constantly required. Physical unclonable functions (PUF) are in the spotlight as an alternative. Chaotic phosphorescent patterns are developed based on an organic crystal and atomic seed heterostructure for security labels with PUFs. Phosphorescent organic crystal patterns are formed on MoS2. They seem similar on a macroscopic scale, whereas each organic crystal exhibits highly disorder features on the microscopic scale. In image analysis, an encoding capacity as a single PUF domain achieves more than 1017 on a MoS2 small fragment with lengths of 25 µm. Therefore, security labels with phosphorescent PUFs can offer superior randomness and no‐cloning codes, possibly becoming a promising security strategy for authentication processes.
Graphene Oxide‐Supported Microwell Grids for Preparing Cryo‐EM Samples with Controlled Ice Thickness
Authors: Kang Min‐Ho , Park Junsun , Kang Sungsu , Jeon Sungho , Lee Minyoung , Shim Ji‐Yeon , Lee Jeeyoung , Jeon Tae Jin , Ahn Min Kyung , Lee Sung Mi , Kwon Ohkyung , Kim Byung Hyo , Meyerson Joel R. , Lee Min Jae , Lim Kwang‐Il , Roh Soung‐Hun , Lee Won Chul , Park Jungwon
Published: September 2021

Cryogenic‐electron microscopy (cryo‐EM) is the preferred method to determine 3D structures of proteins and to study diverse material systems that intrinsically have radiation or air sensitivity. Current cryo‐EM sample preparation methods provide limited control over the sample quality, which limits the efficiency and high throughput of 3D structure analysis. This is partly because it is difficult to control the thickness of the vitreous ice that embeds specimens, in the range of nanoscale, depending on the size and type of materials of interest. Thus, there is a need for fine regulation of the thickness of vitreous ice to deliver consistent high signal‐to‐noise ratios for low‐contrast biological specimens. Herein, an advanced silicon‐chip‐based device is developed which has a regular array of micropatterned holes with a graphene oxide (GO) window on freestanding silicon nitride (SixNy). Accurately regulated depths of micropatterned holes enable precise control of vitreous ice thickness. Furthermore, GO window with affinity for biomolecules can facilitate concentration of the sample molecules at a higher level. Incorporation of micropatterned chips with a GO window enhances cryo‐EM imaging for various nanoscale biological samples including human immunodeficiency viral particles, groEL tetradecamers, apoferritin octahedral, aldolase homotetramer complexes, and tau filaments, as well as inorganic materials.
Reporting Excellent Transverse Piezoelectric and Electro‐Optic Effects in Transparent Rhombohedral PMN‐PT Single Crystal by Engineered Domains
Authors: Deng Chenguang , Ye Lianxu , He Chongjun , Xu Guisheng , Zhai Qinxiao , Luo Haosu , Liu Youwen , Bell Andrew J.
Published: September 2021

Transparent ferroelectric crystals with high piezoelectricity are challenging to build because of their complex structure and disordered domains in rhombohedral relaxor ferroelectrics. There are eight domains along the <111> direction, which cause light scattering. In this study, perfect transparency is achieved along the [110] and [001] directions in [110]‐poled rhombohedral 0.72Pb(Mg1/3Nb2/3)O3‐0.28PbTiO3 (PMN‐PT) crystals, which have a high d31 value of 1700 pC N−1 and a high electro‐optic coefficient γ33 of 320 pm V−1. This implies that the [110]‐oriented rhombohedral PMN‐0.28PT crystal can realize the mode of transverse modulation, whereas the [001]‐oriented PMN‐0.28PT crystal is more suitable for the longitudinal mode. Through piezoresponse force microscopy (PFM), it is confirmed that the [110]‐poled rhombohedral PMN‐PT crystals form 71° layered domains, which are similar to the 109° layered domains of the [001]‐oriented transparent crystal. Combined with PFM and birefringence microscopy, the degradation of domains and thickness dependence of piezoelectricity provide clear evidence for the relationship between the engineered domain structures and piezoelectric properties, which should be considered in the design of piezoelectric or electro‐optic devices with excellent performance. This work enriches the research on ferroelectric domain engineering for excellent transparency and high piezoelectricity to provide new ideas for photoacoustic devices.
A Liquid Metal Artificial Muscle
Authors: Shu Jian , Ge Du‐An , Wang Erlong , Ren Hongtai , Cole Tim , Tang Shi‐Yang , Li Xiangpeng , Zhou Xiangbo , Li Rongjie , Jin Hu , Li Weihua , Dickey Michael D. , Zhang Shiwu
Published: September 2021

Artificial muscles possess a vast potential in accelerating the development of robotics, exoskeletons, and prosthetics. Although a variety of emerging actuator technologies are reported, they suffer from several issues, such as high driving voltages, large hysteresis, and water intolerance. Here, a liquid metal artificial muscle (LMAM) is demonstrated, based on the electrochemically tunable interfacial tension of liquid metal to mimic the contraction and extension of muscles. The LMAM can work in different solutions with a wide range of pH (0–14), generating actuation strains of up to 87% at a maximum extension speed of 15 mm s−1. More importantly, the LMAM only needs a very low driving voltage of 0.5 V. The actuating components of the LMAM are completely built from liquids, which avoids mechanical fatigue and provides actuator linkages without mechanical constraints to movement. The LMAM is used for developing several proof‐of‐concept applications, including controlled displays, cargo deliveries, and reconfigurable optical reflectors. The simplicity, versatility, and efficiency of the LMAM are further demonstrated by using it to actuate the caudal fin of an untethered bionic robotic fish. The presented LMAM has the potential to extend the performance space of soft actuators for applications from engineering fields to biomedical applications.
18.5% Efficiency Organic Solar Cells with a Hybrid Planar/Bulk Heterojunction
Authors: Hong Ling , Yao Huifeng , Cui Yong , Bi Pengqing , Zhang Tao , Cheng Yongxin , Zu Yunfei , Qin Jinzhao , Yu Runnan , Ge Ziyi , Hou Jianhui
Published: September 2021

The donor:acceptor heterojunction has proved as the most successful approach to split strongly bound excitons in organic solar cells (OSCs). Establishing an ideal architecture with selective carrier transport and suppressed recombination is of great importance to improve the photovoltaic efficiency while remains a challenge. Herein, via tailoring a hybrid planar/bulk structure, highly efficient OSCs with reduced energy losses (Elosss) are fabricated. A p‐type benzodithiophene‐thiophene alternating polymer and an n‐type naphthalene imide are inserted on both sides of a mixed donor:acceptor active layer to construct the hybrid heterojunction, respectively. The tailored structure with the donor near the anode and the acceptor near the cathode is beneficial for obtaining enhanced charge transport, extraction, and suppressed charge recombination. As a result, the photovoltaic characterizations suggest a reduced nonradiative Eloss by 25 meV, and the best OSC records a high efficiency of 18.5% (certified as 18.2%). This study highlights that precisely regulating the structure of donor:acceptor heterojunction has the potential to further improve the efficiencies of OSCs.
Liquid Metal Composites with Enhanced Thermal Conductivity and Stability Using Molecular Thermal Linker
Authors: Wang Han , Xing Wenkui , Chen Shen , Song Chengyi , Dickey Michael D. , Deng Tao
Published: September 2021

Gallium‐based liquid metal (LM) composite with metallic fillers is an emerging class of thermal interface materials (TIMs), which are widely applied in electronics and power systems to improve their performance. In situ alloying between gallium and many metallic fillers like copper and silver, however, leads to a deteriorated composite stability. This paper presents an interfacial engineering approach using 3‐chloropropyltriethoxysilane (CPTES) to serve as effective thermal linkers and diffusion barriers at the copper‐gallium oxide interfaces in the LM matrix, achieving an enhancement in both thermal conductivity and stability of the composite. By mixing LM with copper particles modified by CPTES, a thermal conductivity (κ) as high as 65.9 W m−1 K−1 is achieved. In addition, κ can be tuned by altering the terminal groups of silane molecules, demonstrating the flexibility of this approach. The potential use of such composite as a TIM is also shown in the heat dissipation of a computer central processing unit. While most studies on LM‐based composites enhance the material performance via direct mixing of various fillers, this work provides a different approach to fabricate high‐performance LM‐based composites and may further advance their applications in various areas including thermal management systems, flexible electronics, consumer electronics, and biomedical systems.
Quantitative Coassembly for Precise Synthesis of Mesoporous Nanospheres with Pore Structure‐Dependent Catalytic Performance
Authors: Mei Shu‐Chuan , Rui Xian‐Hong , Li Liang , Huang Gui‐Xiang , Pan Xiao‐Qiang , Ke Ming‐Kun , Wang Zhao‐Hua , Yu Han‐Qing , Yu Yan
Published: September 2021

Precise synthesis of porous materials is essential for their applications. Self‐assembly is a widely used strategy for synthesizing porous materials, but quantitative control of the assembly process still remains a great challenge. Here, a quantitative coassembly approach is developed for synthesizing resin/silica composite and its derived porous spheres. The assembly behaviors of the carbon and silica precursors are regulated without surfactants and the growth kinetics of the composite spheres are quantitatively controlled. This assembly approach enables the precise control of the size and pore structures of the derived carbon spheres. These carbon spheres provide a good platform to explore the structure–performance relationships of porous materials, and demonstrate their pore structure‐dependent performance in catalytic water decontamination. This work provides a simple and robust approach for precise synthesis of porous spheres and brings insights into function‐oriented design of porous materials.
Nanocomplex‐Mediated In Vivo Programming to Chimeric Antigen Receptor‐M1 Macrophages for Cancer Therapy
Authors: Kang Mikyung , Lee Seong Ho , Kwon Miji , Byun Junho , Kim Dongyoon , Kim Cheesue , Koo Sagang , Kwon Sung Pil , Moon Sangjun , Jung Mungyo , Hong Jihye , Go Seokhyeong , Song Seuk Young , Choi Jae Hyun , Hyeon Taeghwan , Oh Yu‐Kyoung , Park Hee Ho , Kim Byung‐Soo
Published: September 2021

Chimeric antigen receptor‐T (CAR‐T) cell immunotherapy has shown impressive clinical outcomes for hematologic malignancies. However, its broader applications are challenged due to its complex ex vivo cell‐manufacturing procedures and low therapeutic efficacy against solid tumors. The limited therapeutic effects are partially due to limited CAR‐T cell infiltration to solid tumors and inactivation of CAR‐T cells by the immunosuppressive tumor microenvironment. Here, a facile approach is presented to in vivo program macrophages, which can intrinsically penetrate solid tumors, into CAR‐M1 macrophages displaying enhanced cancer‐directed phagocytosis and anti‐tumor activity. In vivo injected nanocomplexes of macrophage‐targeting nanocarriers and CAR‐interferon‐γ‐encoding plasmid DNA induce CAR‐M1 macrophages that are capable of CAR‐mediated cancer phagocytosis, anti‐tumor immunomodulation, and inhibition of solid tumor growth. Together, this study describes an off‐the‐shelf CAR‐macrophage therapy that is effective for solid tumors and avoids the complex and costly processes of ex vivo CAR‐cell manufacturing.
Plasmonic Nanoparticle Lattice Devices for White‐Light Lasing
Authors: Guan Jun , Li Ran , Juarez Xitlali G. , Sample Alexander D. , Wang Yi , Schatz George C. , Odom Teri W.
Published: September 2021

A plasmonic nanolaser architecture that can produce white‐light emission is reported. A laser device is designed based on a mixed dye solution used as gain material sandwiched between two aluminum nanoparticle (NP) square lattices of different periodicities. The (±1, 0) and (±1, ±1) band‐edge surface lattice resonance (SLR) modes of one NP lattice and the (±1, 0) band‐edge mode of the other NP lattice function as nanocavity modes for red, blue, and green lasing respectively. From a single aluminum NP lattice, simultaneous red and blue lasing is realized from a binary dye solution, and the relative intensities of the two colors are controlled by the volume ratio of the dyes. Also, a laser device is constructed by sandwiching dye solutions between two Al NP lattices with different periodicities, which enables red–green and blue–green lasing. With a combination of three dyes as liquid gain, red, green, and blue lasing for a white‐light emission profile is realized.
Liquid Crystal Elastomers with Enhanced Directional Actuation to Electric Fields
Authors: Fowler Hayden E. , Rothemund Philipp , Keplinger Christoph , White Timothy J.
Published: September 2021

The integration of soft, stimuli‐responsive materials in robotic systems is a promising approach to introduce dexterous and delicate manipulation of objects. Electrical control of mechanical response offers many benefits in robotic systems including the availability of this energy input, the associated response time, magnitude of actuation, and opportunity for self‐regulation. Here, a materials chemistry is detailed to prepare liquid crystal elastomers (LCEs) with a 14:1 modulus contrast and increase in dielectric constant to enhance electromechanical deformation. The inherent modulus contrast of these LCEs (when coated with compliant electrodes) directly convert an electric field to a directional expansion of 20%. The electromechanical response of LCE actuators is observed upon application of voltage ranging from 0.5 to 6 kV. The deformation of these materials is rapid, reaching strain rates of 18% s−1. Upon removal of the electric field, little hysteresis is observed. Patterning the spatial orientation of the nematic director of the LCEs results in a 2D–3D shape transformation to a cone 8 mm in height. Individual and sequential addressing of an array of LCE actuators is demonstrated as a haptic surface.
A Novel Immunomodulator Delivery Platform Based on Bacterial Biomimetic Vesicles for Enhanced Antitumor Immunity
Authors: Hua Liangqun , Yang Zhongqian , Li Weiran , Zhang Qishu , Ren Zhaoling , Ye Chao , Zheng Xiao , Li Duo , Long Qiong , Bai Hongmei , Sun Wenjia , Yang Xu , Zheng Peng , He Jinrong , Chen Yongjun , Huang Weiwei , Ma Yanbing
Published: September 2021

T cell activation‐induced cell death (AICD) during tumor pathogenesis is a tumor immune escape process dependent on dendritic cells (DCs). Proper immune‐modulatory therapies effectively inhibit tumor‐specific CD8+ T cell exhaustion and enhance antitumor immune responses. Here, high‐pressure homogenization is utilized to drive immunomodulator IL10‐modified bacteria to extrude through the gap and self‐assemble into bacterial biomimetic vesicles exposing IL10 (IL10‐BBVs) on the surface with high efficiency. IL10‐BBVs efficiently target DCs in tumor‐draining lymph nodes and thus increase the interaction between IL10 on BBVs and IL10R on DCs to suppress AICD and mitigate CD8+ T cell exhaustion specific to tumor antigens. Two subcutaneous peripheral injections of IL10‐BBVs 1 week apart in tumor‐bearing mice effectively increase systemic and intratumoral proportions of CD8+ T cells to suppress tumor growth and metastasis. Tumor‐specific antigen E7 is enclosed into the periplasm of IL10‐BBVs (IL10‐E7‐BBVs) to realize concurrent actions of the immunomodulator IL10 and the tumor antigen human papillomavirus (HPV) 16E7 in lymph nodes, further enhancing the antitumor effects mediated by CD8+ T cells. The development of this modified BBV delivery platform will expand the application of bacterial membranes and provide novel immunotherapeutic strategies for tumor treatment.
Fundamental Limits to the Refractive Index of Transparent Optical Materials
Authors: Shim Hyungki , Monticone Francesco , Miller Owen D.
Published: September 2021

Increasing the refractive index available for optical and nanophotonic systems opens new vistas for design, for applications ranging from broadband metalenses to ultrathin photovoltaics to high‐quality‐factor resonators. In this work, fundamental limits to the refractive index of any material are derived, given only the underlying electron density and either the maximum allowable dispersion or the minimum bandwidth of interest. In the realm of small to modest dispersion, the bounds are closely approached and not surpassed by a wide range of natural materials, showing that nature has already nearly reached a Pareto frontier for refractive index and dispersion. Conversely, for narrow‐bandwidth applications, nature does not provide the highly dispersive, high‐index materials that the bounds suggest should be possible. The theory of composites to identify metal‐based metamaterials that can exhibit small losses and sizeable increases in refractive index over the current best materials is used. Moreover, if the “elusive lossless metal” can be synthesized, it is shown that it would enable arbitrarily high refractive index in the high‐dispersion regime, nearly achieving the bounds even at refractive indices of 100 and beyond at optical frequencies.
Novel Ultrabright and Air‐Stable Photocathodes Discovered from Machine Learning and Density Functional Theory Driven Screening
Authors: Antoniuk Evan R. , Schindler Peter , Schroeder W. Andreas , Dunham Bruce , Pianetta Piero , Vecchione Theodore , Reed Evan J.
Published: September 2021

The high brightness, low emittance electron beams achieved in modern X‐ray free‐electron lasers (XFELs) have enabled powerful X‐ray imaging tools, allowing molecular systems to be imaged at picosecond time scales and sub‐nanometer length scales. One of the most promising directions for increasing the brightness of XFELs is through the development of novel photocathode materials. Whereas past efforts aimed at discovering photocathode materials have typically employed trial‐and‐error‐based iterative approaches, this work represents the first data‐driven screening for high brightness photocathode materials. Through screening over 74 000 semiconducting materials, a vast photocathode dataset is generated, resulting in statistically meaningful insights into the nature of high brightness photocathode materials. This screening results in a diverse list of photocathode materials that exhibit intrinsic emittances that are up to 4x lower than currently used photocathodes. In a second effort, multiobjective screening is employed to identify the family of M2O (M = Na, K, Rb) that exhibits photoemission properties that are comparable to the current state‐of‐the‐art photocathode materials, but with superior air stability. This family represents perhaps the first intrinsically bright, visible light photocathode materials that are resistant to reactions with oxygen, allowing for their transport and storage in dry air environments.
Molecular Ferroelectric‐Based Flexible Sensors Exhibiting Supersensitivity and Multimodal Capability for Detection
Authors: Li Wenru , Li Changhao , Zhang Guangzu , Li Linkai , Huang Kai , Gong Xuetian , Zhang Chao , Zheng An , Tang Yanxue , Wang Zhengzhi , Tong Qiaoling , Dong Wen , Jiang Shenglin , Zhang Sulin , Wang Qing
Published: September 2021

Although excellent dielectric, piezoelectric, and pyroelectric properties matched with or even surpassing those of ferroelectric ceramics have been recently discovered in molecular ferroelectrics, their successful applications in devices are scarce. The fracture proneness of molecular ferroelectrics under mechanical loading precludes their applications as flexible sensors in bulk crystalline form. Here, self‐powered flexible mechanical sensors prepared from the facile deposition of molecular ferroelectric [C(NH2)3]ClO4 onto a porous polyurethane (PU) matrix are reported. [C(NH2)3]ClO4‐PU is capable of detecting pressure of 3 Pa and strain of 1% that are hardly accessible by the state‐of‐the‐art piezoelectric, triboelectric, and piezoresistive sensors, and presents the ability of sensing multimodal mechanical forces including compression, stretching, bending, shearing, and twisting with high cyclic stability. This scaling analysis corroborated with computational modeling provides detailed insights into the electro‐mechanical coupling and establishes rules of engineering design and optimization for the hybrid sponges. Demonstrative applications of the [C(NH2)3]ClO4‐PU array suggest potential uses in interactive electronics and robotic systems.
Anisotropic Nodal‐Line‐Derived Large Anomalous Hall Conductivity in ZrMnP and HfMnP
Authors: Singh Sukriti , Noky Jonathan , Bhattacharya Shaileyee , Vir Praveen , Sun Yan , Kumar Nitesh , Felser Claudia , Shekhar Chandra
Published: September 2021

The nontrivial band structure of semimetals has attracted substantial research attention in condensed matter physics and materials science in recent years owing to its intriguing physical properties. Within this class, a group of nontrivial materials known as nodal‐line semimetals is particularly important. Nodal‐line semimetals exhibit the potential effects of electronic correlation in nonmagnetic materials, whereas they enhance the contribution of the Berry curvature in magnetic materials, resulting in high anomalous Hall conductivity (AHC). In this study, two ferromagnetic compounds, namely ZrMnP and HfMnP, are selected, wherein the abundance of mirror planes in the crystal structure ensures gapped nodal lines at the Fermi energy. These nodal lines result in one of the largest AHC values of 2840 Ω−1 cm−1, with a high anomalous Hall angle of 13.6% in these compounds. First‐principles calculations provide a clear and detailed understanding of nodal line‐enhanced AHC. The finding suggests a guideline for searching large AHC compounds.