Npg Asia Materials最新文献

{"title":"Ultrabroadband absorptive refractory plasmonics for photocatalytic hydrogen evolution reactions","authors":"Myeongcheol Go, Inju Hong, Dasol Lee, Sanghoon Kim, Junho Jang, Keon-Woo Kim, Sangmin Shim, Kijung Yong, Junsuk Rho, Jin Kon Kim","doi":"10.1038/s41427-023-00523-7","DOIUrl":"10.1038/s41427-023-00523-7","url":null,"abstract":"As an environmentally friendly and renewable method for hydrogen production powered by solar energy, photocatalytic hydrogen evolution reactions (HERs) using broadband absorbers have received much attention. Here, we report the fabrication and characterization of an ultrabroadband absorber for the photocatalytic HER. The absorber is composed of titanium nitride and titanium dioxide heterostructures deposited onto a porous anodized aluminum oxide template. The absorber shows ultrabroadband absorption in both the visible and near-infrared regions (400–2500 nm), with averages of 99.1% and 80.1%, respectively. Additionally, the presence of the TiO2 layer within the absorber extends the lifetime of the hot carriers by 2.7 times longer than that without the TiO2 layer, enhancing the transfer of hot electrons and improving the efficiency of hydrogen production by 1.9 times. This novel ultrabroadband absorber has potential use in advanced photocatalytic HER applications, providing a sustainable and cost-effective route for hydrogen generation from solar energy. Researchers have developed an ultrabroadband absorber for reactions that produce hydrogen using light (photocatalytic hydrogen evolution reactions), which could improve the efficiency of hydrogen production using solar energy. The team, led by M. G. and I. H., used a porous AAO template (a structure used for depositing materials), depositing TiO2 and TiN (types of chemical compounds) onto it to create a material that can absorb light across a wide spectrum. The study showed that adding the TiO2 layer increased the lifetime of hot carriers (energized particles called electrons and holes) by 2.7 times, leading to better electron transfer and improved hydrogen production efficiency. They believe this new absorber could be used for affordable hydrogen production, using environmentally friendly and renewable solar energy. Future research will explore the potential uses and scalability of this technology. This summary was initially drafted using artificial intelligence, then revised and fact-checked by the author. The ultrabroadband absorptive refractory plasmonics is demonstrated with TiN and TiO2 deposited onto an anodized aluminum oxide template. The absorber shows ultrabroadband absorption in the solar spectrum (400–2500 nm). Furthermore, the absorber shows an extended hot carrier lifetime and improved efficiency of photocatalytic hydrogen production. This novel ultrabroadband absorber has great potential to provide a sustainable and cost-effective route for hydrogen generation from solar energy.","PeriodicalId":19382,"journal":{"name":"Npg Asia Materials","volume":"16 1","pages":"1-8"},"PeriodicalIF":8.6,"publicationDate":"2024-01-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41427-023-00523-7.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139510406","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The central role of tilted anisotropy for field-free spin–orbit torque switching of perpendicular magnetization","authors":"Chen-Yu Hu, Wei-De Chen, Yan-Ting Liu, Chao-Chung Huang, Chi-Feng Pai","doi":"10.1038/s41427-023-00521-9","DOIUrl":"10.1038/s41427-023-00521-9","url":null,"abstract":"The discovery of efficient magnetization switching upon device activation by spin Hall effect (SHE)-induced spin–orbit torque (SOT) changed the course of magnetic random-access memory (MRAM) research and development. However, for electronic systems with perpendicular magnetic anisotropy (PMA), the use of SOT is still hampered by the necessity of a longitudinal magnetic field to break magnetic symmetry and achieve deterministic switching. In this work, we demonstrate that robust and tunable field-free current-driven SOT switching of perpendicular magnetization can be controlled by the growth protocol in Pt-based magnetic heterostructures. We further elucidate that such growth-dependent symmetry breaking originates from the laterally tilted magnetic anisotropy of the ferromagnetic layer with PMA, a phenomenon that has been largely neglected in previous studies. We show experimentally and in simulation that in a PMA system with tilted anisotropy, the deterministic field-free switching exhibits a conventional SHE-induced damping-like torque feature, and the resulting current-induced effective field shows a nonlinear dependence on the applied current density. This relationship could be potentially misattributed to an unconventional SOT origin. This study explores a novel approach to achieve field-free current-driven spin–orbit torque switching of perpendicular magnetization for MRAM applications. By adjusting growth protocols in Pt-based magnetic heterostructures, a previously overlooked laterally tilted texture and magnetic anisotropy are harnessed. These findings allow deterministic switching of perpendicular magnetization without an external magnetic field. Contrary to conventional assumptions, the observed nonlinear dependence on current density resembles a damping-like torque, challenging previous notions about its origin.","PeriodicalId":19382,"journal":{"name":"Npg Asia Materials","volume":"16 1","pages":"1-10"},"PeriodicalIF":8.6,"publicationDate":"2024-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41427-023-00521-9.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139459829","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Strain-induced specific orbital control in a Heusler alloy-based interfacial multiferroics","authors":"Jun Okabayashi, Takamasa Usami, Amran Mahfudh Yatmeidhy, Yuichi Murakami, Yu Shiratsuchi, Ryoichi Nakatani, Yoshihiro Gohda, Kohei Hamaya","doi":"10.1038/s41427-023-00524-6","DOIUrl":"10.1038/s41427-023-00524-6","url":null,"abstract":"For the development of spintronic devices, the control of magnetization by a low electric field is necessary. The microscopic origin of manipulating spins relies on the control of orbital magnetic moments (morb) by strain; this is essential for the high performance magnetoelectric (ME) effect. Herein, electric-field induced X-ray magnetic circular dichroism (XMCD) is used to determine the changes in morb by piezoelectric strain and clarify the relationship between the strain and morb in an interfacial multiferroics system with a significant ME effect; the system consists of the Heusler alloy Co2FeSi on a ferroelectric Pb(Mg1/3Nb2/3)O3-PbTiO3 substrate. Element-specific investigations of the orbital states by operando XMCD and the local environment via extended X-ray absorption fine structure (EXAFS) analysis show that the modulation of only the Fe sites in Co2FeSi primarily contributes to the giant ME effect. The density functional theory calculations corroborate this finding, and the growth of the high index (422) plane in Co2FeSi results in a giant ME effect. These findings elucidate the element-specific orbital control using reversible strain, called the ‘orbital elastic effect,’ and can provide guidelines for material designs with a giant ME effect. Schematic illustrations of the changes in the magnetic anisotropy by an applied electric field (E) in the strain directions are displayed. Under an applied E, the piezoelectric stress in the ferroelectric PMN-PT could be introduced in the tensile and compressive directions using positive and negative bias voltages, respectively, resulting in the changes in the magnetic anisotropy in the Co2FeSi layer. The XMCD spectra of Fe and Co L-edges in Co2FeSi under applying E showed the line shape changes only in the Fe site, which corresponds to the changes of orbital magnetic moment in Fe, while that in Co remains unchanged.","PeriodicalId":19382,"journal":{"name":"Npg Asia Materials","volume":"16 1","pages":"1-10"},"PeriodicalIF":8.6,"publicationDate":"2024-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41427-023-00524-6.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139439847","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Role of the structure order in the transport and magnetic properties of high-entropy alloy films","authors":"Jia-Wei Chen, Shih-Hsun Chen, Padraic Shafer, Wen-Yen Tzeng, Yi-Cheng Chen, Chih-Wei Luo, Wen-Wei Wu, Jien-Wei Yeh, Ying-Hao Chu","doi":"10.1038/s41427-023-00518-4","DOIUrl":"10.1038/s41427-023-00518-4","url":null,"abstract":"The fabrication and development of high-entropy alloys (HEAs) with exceptional functionalities is a rapidly expanding field with numerous applications. When the role of entropy in HEAs is considered, the extrinsic factors, such as the existence of grains and different phases, need to be separated from the intrinsic configurations of the atomic lattice. Here, we fabricated the CoCrFeNi2Al0.5 HEA/muscovite heterostructures, and some were prepared as epitaxial bilayers and others were prepared as an amorphous system. These two systems are classified into atomic-site disordered (ASD) and structurally disordered (SD) states, respectively, without the extrinsic effects for the determination of the crystal lattice role in high-entropy states. In this study, we determined the role of the structure order in correlation with the structural, electronic, and magnetic properties of HEAs using a combination of energy-dispersive X-ray spectrometry, X-ray diffraction, transmission electron microscopy, magneto-transport, ac magnetometry, and X-ray absorption spectroscopy with magnetic circular dichroism. The ASD state showed fully metallic behavior. In contrast, the SD state showed a metallic behavior with intense magnetic saturation, which was called Kondo-like behavior, under 50 K with a low-temperature coefficient of resistivity of ~64 ppm/°C. The difference between the saturation magnetic moment and the electron relaxation behavior in the ASD and SD states resulted from the existence of the structural order affecting the atomic distance and periodicity to modify the exchange interaction and tune the electron-phonon interaction for scattering. The ferromagnetic behavior contributed by Co, Fe, and Ni atoms was probed by X-ray absorption and magnetic circular dichroism to understand the magnetic interactions in the ASD and SD states. The fabrication and development of high-entropy alloys (HEAs) with exceptional functionalities is a rapidly expanding field. The extrinsic factors, such as the existence of grains and different phases, would complicate understanding the physical phenomena. We classified the epitaxial system into atomic-site disordered (ASD) and amorphous system into structurally disordered (SD) states, respectively, to exclude the extrinsic effects of HEAs. With a comprehensive study of the magnetic and transport properties, we can further promote the research of high entropy systems.","PeriodicalId":19382,"journal":{"name":"Npg Asia Materials","volume":"15 1","pages":"1-8"},"PeriodicalIF":8.6,"publicationDate":"2024-01-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41427-023-00518-4.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139093623","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Two-dimensional directed lamellar assembly in silicon- and fluorine-containing block copolymer with identical surface energies","authors":"Seungbae Jeon, Seungjae Lee, Junsu Kim, Sungoh Eim, Wooseop Lee, Woo Hyun Nam, Jeong Gon Son, Du Yeol Ryu","doi":"10.1038/s41427-023-00519-3","DOIUrl":"10.1038/s41427-023-00519-3","url":null,"abstract":"A block copolymer (BCP) with specific monomer structures of fluoroacrylate polymers was designed by exploiting the inorganic superhydrophobicity and low glass transition temperature of polydimethylsiloxane (PDMS). With the use of a fluorine-containing block providing a surface tension as low as that of PDMS (19.9 < $$gamma$$  < 21.5 mN/m), PDMS-b-poly(2,2,3,3,3-pentafluoropropyl acrylate) (PDMS-b-PPeFPA) copolymer was synthesized to create a volume-symmetric lamellar structure. The compositional randomness of the BCP chains adsorbed onto the substrates provided well-balanced interfacial interactions toward the overlaid PDMS-b-PPeFPA ( $$gamma$$ PDMS-ads ≈  $$gamma$$ PPeFPA-ads). Under this symmetric confinement with simultaneous dual neutral interfaces, lamellar microdomains with a sub-10 nm half-pitch feature size were successfully oriented perpendicular to the interfaces at room temperature. We showed the response of the BCP films to a lateral electric field, demonstrating that the perpendicular lamellae were adaptively aligned along the electric vector within a short treatment period. Furthermore, the PDMS-b-PPeFPA system exhibited a remarkable etch contrast for O2 reactive ion etching, yielding unidirectionally aligned air–inorganic nanoarrays emanating from the perpendicular lamellae between the electrodes. This study reports a system engineering approach for conceiving highly immiscible, silicon- and fluorine-containing BCP whose components exhibit identical surface tensions ( $$gamma$$ PDMS ≈  $$gamma$$ PPeFPA) and for generating perpendicularly oriented lamellar microdomains due to substrate neutrality. With the use of a fluorine-containing block providing a surface tension as low as that of PDMS (19.9 < $$gamma$$  < 21.5 mN/m), the PDMS-b-PPeFPA copolymer is synthesized to create a volume-symmetric lamellar structure. Under the symmetric confinement with simultaneous dual neutral interfaces, lamellar microdomains with a sub-10 nm half-pitch feature size are successfully oriented perpendicular to the interfaces at room temperature (RT). Together with unidirectionally aligned perpendicular lamellae along the electric vector in a short period (0.5 h) at RT, we demonstrate a unidirectional alignment of the perpendicular air–inorganic (oxidized PDMS) lamellae between the electrodes.","PeriodicalId":19382,"journal":{"name":"Npg Asia Materials","volume":"15 1","pages":"1-10"},"PeriodicalIF":8.6,"publicationDate":"2023-12-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41427-023-00519-3.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139066880","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Recent progress in thermoelectric layered cobalt oxide thin films","authors":"Yuqiao Zhang, Hiromichi Ohta","doi":"10.1038/s41427-023-00520-w","DOIUrl":"10.1038/s41427-023-00520-w","url":null,"abstract":"Oxide-based thermoelectric materials that show a high figure of merit are promising because of their good chemical and thermal stabilities and their relative harmlessness compared with chalcogenide-based state-of-the-art thermoelectric materials. Although several high-ZT thermoelectric oxides (ZT > 1) have been reported thus far, their reliability levels are low due to the lack of careful observations of their stabilities at elevated temperatures. Herein, we review the epitaxial film growth and thermoelectric properties of representative p-type layered cobalt oxides: Na3/4CoO2, Ca1/3CoO2, Sr1/3CoO2, Ba1/3CoO2, and Ca3Co4O9. Among these specimens, Ba1/3CoO2 and Ca3Co4O9 are stable in air at elevated temperatures (~600 °C). The ZT of Ba1/3CoO2 reaches ~ 0.55 at 600 °C in air, which is reliable and the highest among thermoelectric oxides. Moreover, this value is comparable to those of p-type PbTe and p-type SiGe. Oxide-based thermoelectric materials that exhibit a high figure of merit are promising because of their good chemical and thermal stabilities and their relative harmlessness compared with chalcogenide-based state-of-the-art thermoelectric materials. The layered barium-cobalt oxide (Ba1/3CoO2) exhibits a record-high ZT of 0.55 at 600 °C in air. The increase in ZT is directly originated by the decreased thermal conductivity of Ba1/3CoO2. As we hypothesized, the greater the atomic mass, the lower the thermal conductivity, resulting in higher ZT. The ZT is reliable and the highest among thermoelectric oxides. Moreover, this value is comparable to those of p-type PbTe and p-type SiGe.","PeriodicalId":19382,"journal":{"name":"Npg Asia Materials","volume":"15 1","pages":"1-9"},"PeriodicalIF":8.6,"publicationDate":"2023-12-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41427-023-00520-w.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139066883","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Highly responsive diabetes and asthma sensors with WO3 nanoneedle films for the detection of biogases with low concentrations","authors":"Yoshitake Masuda, Ayako Uozumi","doi":"10.1038/s41427-023-00515-7","DOIUrl":"10.1038/s41427-023-00515-7","url":null,"abstract":"A diabetes sensor was developed to detect low concentrations of acetone gas, which is a diabetes biomarker. A WO3 nanoneedle film was synthesized via an aqueous process for use as a sensitive sensing membrane. Acetone was adsorbed and oxidized on the WO3 nanoneedle film, which changed the sensor resistance. The sensor exhibited a high response of Ra/Rg = 19.72, where Ra is the sensor resistance in air, and Rg is the sensor resistance in air containing 10 ppmv acetone gas. The sensor also exhibited a high response (25.36) to 1 ppmv NO2, which is related to asthma. Furthermore, the sensor responded to various biogases associated with diseases. The sensor responses to 10 ppmv of the lung cancer marker gases acetaldehyde and toluene were 13.54 and 9.49, respectively. The sensor responses to 10 ppmv isoprene, ethanol, para-xylene, hydrogen, and NH3 were 7.93, 6.33, 4.51, 2.08, and 0.90, respectively. Trace amounts of acetone and NO2 gases (25 and 250 ppbv, respectively) were detected. The limits of detection for acetone and NO2 gases were estimated to be 2.4 and 1.5 ppbv, respectively. The sensor exhibited superior ability to detect low concentrations of biomarker gases. The unique characteristics of the WO3 nanoneedle film contributed to its high response rates. A WO3 nanoneedle film was developed for a gas sensor to detect low concentrations of acetone gas, which is a diabetes biomarker. The sensor exhibited a high response (19.72) to 10 ppmv acetone gas. The sensor also exhibited a high response (25.36) to 1 ppmv NO2, which is related to asthma. The limits of detection for acetone and NO2 gases were estimated to be 2.4 and 1.5 ppbv, respectively. The sensor exhibited superior ability to detect low concentrations of biomarker gases. The unique characteristics of the WO3 nanoneedle film contributed to its high response rates.","PeriodicalId":19382,"journal":{"name":"Npg Asia Materials","volume":"15 1","pages":"1-18"},"PeriodicalIF":8.6,"publicationDate":"2023-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41427-023-00515-7.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138946309","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Design of ohmic contacts between Janus MoSSe and two-dimensional metals","authors":"Ning Zhao, Shubham Tyagi, Udo Schwingenschlögl","doi":"10.1038/s41427-023-00517-5","DOIUrl":"10.1038/s41427-023-00517-5","url":null,"abstract":"Two-dimensional semiconductors are considered as channel materials for field-effect transistors to overcome short-channel effects and reduce the device size. As the contacts to the metallic electrodes are decisive for the device performance, we study the electronic properties of contacts between Janus MoSSe and various two-dimensional metals. We demonstrate that weak interactions at these van der Waals contacts suppress Fermi level pinning and show that ohmic contacts can be formed for both terminations of Janus MoSSe, generating favorable transport characteristics. Two-dimensional semiconductors are considered as field-effect transistors to overcome short channel effects and reduce the device size. As contacts to the metallic electrodes are decisive for the device performance, we study the electronic properties of contacts between Janus MoSSe and various two-dimensional metals. We demonstrate that weak interactions at these van der Waals contacts suppress Fermi level pinning and show that ohmic contacts can be formed for both terminations of Janus MoSSe, generating favorable transport characteristics.","PeriodicalId":19382,"journal":{"name":"Npg Asia Materials","volume":"15 1","pages":"1-7"},"PeriodicalIF":8.6,"publicationDate":"2023-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41427-023-00517-5.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138947688","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hemozoin in malaria eradication—from material science, technology to field test","authors":"Ashutosh Rathi, Z. Chowdhry, Anand Patel, Siming Zuo, Thulya Chakkumpulakkal Puthan Veettil, John A. Adegoke, Hadi Heidari, Bayden R. Wood, Vidya Praveen Bhallamudi, Weng Kung Peng","doi":"10.1038/s41427-023-00516-6","DOIUrl":"10.1038/s41427-023-00516-6","url":null,"abstract":"Malaria continues to be among the most lethal infectious diseases. Immediate barriers include the detection of low-parasitemia levels in asymptomatic individuals, which act as a reservoir for future infections, and the emergence of multidrug-resistant strains in malaria-endemic, under-resourced regions. The development of technologies for field-deployable devices for early detection and targeted drugs/vaccines is an ongoing challenge. In this respect, the identification of hemozoin during the Plasmodium growth cycle presents a unique opportunity as a biomarker for malaria infection. The last decade has witnessed the development of numerous opto-/magnetic- based ultrasensitive hemozoin sensing technologies with tremendous potential of rapid and accurate malaria diagnosis and drug testing. The unique information in hemozoin formation can also shed light on the development of targeted drugs. Here, we present a comprehensive perspective on state-of-the-art hemozoin-based methodologies for detecting and studying malaria. We discuss the challenges (and opportunities) to expedite the translation of the technology as a point-of-site tool to assist in the global eradication of malaria infection. Malaria continues to be among the most lethal infectious diseases. In the last two decades, we have witnessed unprecedented success in reducing the mortality rate. With the UN resolution of eradicating malaria by 2030 approaching fast, the scientific community has devoted substantial attention to interdisciplinary research using the latest opto-/magnetic-based technologies to detect a novel biomarker coming from the malarial pigment (hemozoin), which also carries vital information for discovering targeted drugs. This perspective article looks into the growing interest in this field and discusses the practical applicability of these sensing technologies.","PeriodicalId":19382,"journal":{"name":"Npg Asia Materials","volume":"15 1","pages":"1-27"},"PeriodicalIF":8.6,"publicationDate":"2023-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41427-023-00516-6.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138944753","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Swift 4D printing of thermoresponsive shape-memory polymers using vat photopolymerization","authors":"Fahad Alam, Jabir Ubaid, Haider Butt, Nazek El-Atab","doi":"10.1038/s41427-023-00511-x","DOIUrl":"10.1038/s41427-023-00511-x","url":null,"abstract":"Shape-memory polymers (SMPs) are smart materials that have gained significant attention in recent years owing to their widespread application in smart structures and devices. Digital light processing (DLP), a vat-photopolymerization-based technique, is a significantly faster technology for printing a complete layer in a single step. The current study reports a facile and fast method for the 3D printing of SMP-based smart structures using a DLP 3D printer and a customized resin. A liquid crystal (LC, RM257) was combined with the resin to introduce shape-memory properties. The combination of LCs in photocurable resin provides the opportunity to directly 3D-print thermoresponsive structures, avoiding the complexity of SMP resin preparation. The structures were printed with different geometries, and the shape-memory response was measured. Lattice structures were fabricated and programmed to obtain tunable mechanical properties. Furthermore, the strain-sensing response was measured to demonstrate the utility of these lattice structures as smart patches for joint-movement sensing. The SMPs can be prepared conveniently and can potentially be used for various applications, such as smart tools, toys, and meta-material sensors. Shape-memory polymers, also known as shape-shifting materials, can morph due to changes in their environment. However, the optimal use of these materials for complex 3D designs is still uncertain. Scientists from King Abdullah University of Science and Technology utilized a commercially available 3D printer to investigate this issue. They merged a shape-memory polymer with a liquid crystal (a substance that can modify its characteristics with temperature), to produce a resin for use in the 3D printer. They showed the possibility of printing diverse complex objects, from lattice structures to toys, which could transform their shape when heated and regain their original shape upon reheating. This study underscores the potential of 3D printing for developing smart materials with shape-memory features. This technology could be advantageous in various domains, including medicine and robotics. This summary was initially drafted using artificial intelligence, then revised and fact-checked by the author. In this work, 3D printing shape of memory polymer (SMP) based smart structures is conducted using a Digital light processing 3D printer and a customized resin in combination with liquid crystals. Lattice structures are fabricated and programmed to achieve tunable mechanical properties. The strain-sensing response is measured to demonstrate the utility of these lattice structures as smart patches for joint movement sensing. Changes in the electrical resistance are measured during the stretching and compression of the structure. The SMPs can be prepared conveniently and can potentially be used for various applications, such as smart tools, toys, and meta-material sensors.","PeriodicalId":19382,"journal":{"name":"Npg Asia Materials","volume":"15 1","pages":"1-12"},"PeriodicalIF":8.6,"publicationDate":"2023-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41427-023-00511-x.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138683505","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}