M. Tuerlings, I. Boone, H. Eslami Amirabadi, M. Vis, E. Suchiman, E. Linden, S. Hofmann, R. Nelissen, J. Toonder, Y. Ramos, I. Meulenbelt
Given the multi‐tissue aspects of osteoarthritis (OA) pathophysiology, translation of OA susceptibility genes towards underlying biological mechanism and eventually drug target discovery requires appropriate human in vitro OA models that incorporate both functional bone and cartilage tissue units. Therefore, a microfluidic chip is developed with an integrated fibrous polycaprolactone matrix in which neo‐bone and cartilage are produced, that could serve as a tailored human in vitro disease model of the osteochondral unit of joints. The model enables to evaluate OA‐related environmental perturbations to (individual) tissue units by controlling environmental cues, for example by adding biochemical agents. After establishing the co‐culture in the system, a layer of cartilaginous matrix is deposited in the chondrogenic compartment, while a bone‐like matrix is deposited between the fibers, indicated by both histology and gene expression levels of collagen type 2 and osteopontin, respectively. As proof‐of‐principle, the bone and cartilaginous tissue are exposed to active thyroid hormone, creating an OA disease model. This results in increased expression levels of hypertrophy markers integrin‐binding sialoprotein and alkaline phosphatase in both cartilage and bone, as expected. Altogether, this model could contribute to enhanced translation from OA risk genes towards novel OA therapies.
{"title":"Capturing Essential Physiological Aspects of Interacting Cartilage and Bone Tissue with Osteoarthritis Pathophysiology: A Human Osteochondral Unit‐on‐a‐Chip Model","authors":"M. Tuerlings, I. Boone, H. Eslami Amirabadi, M. Vis, E. Suchiman, E. Linden, S. Hofmann, R. Nelissen, J. Toonder, Y. Ramos, I. Meulenbelt","doi":"10.1002/admt.202101310","DOIUrl":"https://doi.org/10.1002/admt.202101310","url":null,"abstract":"Given the multi‐tissue aspects of osteoarthritis (OA) pathophysiology, translation of OA susceptibility genes towards underlying biological mechanism and eventually drug target discovery requires appropriate human in vitro OA models that incorporate both functional bone and cartilage tissue units. Therefore, a microfluidic chip is developed with an integrated fibrous polycaprolactone matrix in which neo‐bone and cartilage are produced, that could serve as a tailored human in vitro disease model of the osteochondral unit of joints. The model enables to evaluate OA‐related environmental perturbations to (individual) tissue units by controlling environmental cues, for example by adding biochemical agents. After establishing the co‐culture in the system, a layer of cartilaginous matrix is deposited in the chondrogenic compartment, while a bone‐like matrix is deposited between the fibers, indicated by both histology and gene expression levels of collagen type 2 and osteopontin, respectively. As proof‐of‐principle, the bone and cartilaginous tissue are exposed to active thyroid hormone, creating an OA disease model. This results in increased expression levels of hypertrophy markers integrin‐binding sialoprotein and alkaline phosphatase in both cartilage and bone, as expected. Altogether, this model could contribute to enhanced translation from OA risk genes towards novel OA therapies.","PeriodicalId":7200,"journal":{"name":"Advanced Materials & Technologies","volume":"31 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78017535","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
R. Wu, K. Kwan, He Lin, Pu Li, Xia Long, Shihe Yang, A. Ngan
Living organisms are imparted with compact intelligence in which a myriad of functionalities are delivered by highly integrated and demodularized subunits, as in the case of the mammalian skin in which different embedding stimuli‐receptors and follicles work together to provide rich sensation for temperature and tactility, as well as the visible and regulatory response of hair erection via the arrector pili muscle. A breakthrough in robotics is to create similar intelligence using emerging stimuli‐responsive materials. Here, a thin film composite comprising a transition metal oxide/hydroxide layer for sensation and high‐performing actuation under environmental stimuli including visible light, humidity, and temperature, and a graphene‐based layer for feedback strain sensing, is developed to demonstrate such an approach of robotics. The system is used to construct robotic hair that mimics well mammalian hair in functionality, and devices for sensing objects for their effective manipulation. This research opens a “material intelligence” approach for robotics.
{"title":"Robotic Hair with Rich Sensation and Piloerection Functionalities Biomimicked by Stimuli‐Responsive Materials","authors":"R. Wu, K. Kwan, He Lin, Pu Li, Xia Long, Shihe Yang, A. Ngan","doi":"10.1002/admt.202200184","DOIUrl":"https://doi.org/10.1002/admt.202200184","url":null,"abstract":"Living organisms are imparted with compact intelligence in which a myriad of functionalities are delivered by highly integrated and demodularized subunits, as in the case of the mammalian skin in which different embedding stimuli‐receptors and follicles work together to provide rich sensation for temperature and tactility, as well as the visible and regulatory response of hair erection via the arrector pili muscle. A breakthrough in robotics is to create similar intelligence using emerging stimuli‐responsive materials. Here, a thin film composite comprising a transition metal oxide/hydroxide layer for sensation and high‐performing actuation under environmental stimuli including visible light, humidity, and temperature, and a graphene‐based layer for feedback strain sensing, is developed to demonstrate such an approach of robotics. The system is used to construct robotic hair that mimics well mammalian hair in functionality, and devices for sensing objects for their effective manipulation. This research opens a “material intelligence” approach for robotics.","PeriodicalId":7200,"journal":{"name":"Advanced Materials & Technologies","volume":"14 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88861943","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. D. M. González del Campo, Andreu Vaquer, R. de la Rica
In recent years, paper has become an essential substrate material for developing different types of sensors, from wearable devices to single‐use test strips and biosensors. In parallel, a polymer‐based toolbox has emerged in order to add additional functions to these paper‐based analytical devices. In this article, examples are compiled from the recent literature showing microfluidic systems based on printing impermeable polymer barriers with different methods as well as the implementation of electrochemical, fluorescent, and colorimetric polymer‐based transducers in paper‐based analytical platforms. Externally actuated or dissolvable polymer valves and reservoirs, analyte concentrators, and separation devices, as well as polymer‐based recognition elements (molecularly imprinted polymers) printed on paper substrates are also reviewed. The search has revealed a plethora of possibilities for developing complex lab‐on‐chip devices implementing different polymer‐based components in them. The ability of patterning these polymers with common printing methods that do not require specialized facilities paves the way for mass producing this kind of advanced paper‐based analytical device.
{"title":"Polymer Components for Paper‐Based Analytical Devices","authors":"M. D. M. González del Campo, Andreu Vaquer, R. de la Rica","doi":"10.1002/admt.202200140","DOIUrl":"https://doi.org/10.1002/admt.202200140","url":null,"abstract":"In recent years, paper has become an essential substrate material for developing different types of sensors, from wearable devices to single‐use test strips and biosensors. In parallel, a polymer‐based toolbox has emerged in order to add additional functions to these paper‐based analytical devices. In this article, examples are compiled from the recent literature showing microfluidic systems based on printing impermeable polymer barriers with different methods as well as the implementation of electrochemical, fluorescent, and colorimetric polymer‐based transducers in paper‐based analytical platforms. Externally actuated or dissolvable polymer valves and reservoirs, analyte concentrators, and separation devices, as well as polymer‐based recognition elements (molecularly imprinted polymers) printed on paper substrates are also reviewed. The search has revealed a plethora of possibilities for developing complex lab‐on‐chip devices implementing different polymer‐based components in them. The ability of patterning these polymers with common printing methods that do not require specialized facilities paves the way for mass producing this kind of advanced paper‐based analytical device.","PeriodicalId":7200,"journal":{"name":"Advanced Materials & Technologies","volume":"298 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-04-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79921011","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Oil–water emulsions are a considerable hazard to the environment, ecology, and human health, if not appropriately treated. This study proposes a self‐powered and efficient triboelectric dehydrator (TED) based on a wind‐driven freestanding rotary triboelectric nanogenerator (FR‐TENG) to separate water‐in‐oil emulsions. This TED can form a high‐voltage electric field in the emulsion when the FR‐TENG is driven by mechanical energy. The dehydration performance of the TED is analyzed in detail through multiphysics‐coupled models and experiments. It is found that the TED can dehydrate water‐in‐oil emulsions with a wide range of initial moisture contents. In particular, even when the initial moisture content is 60%, which is near the phase inversion concentration of the emulsion, the dehydration rate of the TED can still reach 99.41%. In addition, the performance of TED is demonstrated in a simulated situation of wind, suggesting that the present TED has great potential application for separating oil–water emulsions by harvesting environmental energy.
{"title":"A Self‐Powered and Efficient Triboelectric Dehydrator for Separating Water‐in‐Oil Emulsions with Ultrahigh Moisture Content","authors":"Fangming Li, X. Wan, Jiaju Hong, Xinyang Guo, Minzheng Sun, Haijia Lv, Hao Wang, Jianchun Mi, Jia Hua Cheng, Xinxiang Pan, Minyi Xu, Zhong Lin Wang","doi":"10.1002/admt.202200198","DOIUrl":"https://doi.org/10.1002/admt.202200198","url":null,"abstract":"Oil–water emulsions are a considerable hazard to the environment, ecology, and human health, if not appropriately treated. This study proposes a self‐powered and efficient triboelectric dehydrator (TED) based on a wind‐driven freestanding rotary triboelectric nanogenerator (FR‐TENG) to separate water‐in‐oil emulsions. This TED can form a high‐voltage electric field in the emulsion when the FR‐TENG is driven by mechanical energy. The dehydration performance of the TED is analyzed in detail through multiphysics‐coupled models and experiments. It is found that the TED can dehydrate water‐in‐oil emulsions with a wide range of initial moisture contents. In particular, even when the initial moisture content is 60%, which is near the phase inversion concentration of the emulsion, the dehydration rate of the TED can still reach 99.41%. In addition, the performance of TED is demonstrated in a simulated situation of wind, suggesting that the present TED has great potential application for separating oil–water emulsions by harvesting environmental energy.","PeriodicalId":7200,"journal":{"name":"Advanced Materials & Technologies","volume":"7 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-04-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81727607","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jiangjing Wang, Han Zhang, Xudong Wang, Lu Lu, Chunlin Jia, Wei Zhang, R. Mazzarello
Ge–Sb–Te (GST) alloys are an important family of phase‐change materials employed in non‐volatile memories and neuromorphic devices. Conventional memory cells based on GST rely on the switching between an amorphous state and a metastable, disordered rocksalt‐like phase. Recently, however, it has been proposed that a special type of defect in layer‐structured GST—the so called “swapped bilayer” defect—is responsible for a novel phase‐change mechanism observed in GST‐based superlattices. Thus, disorder appears to play an important role in both types of switching mechanisms. Here, the observation of a new in‐plane twinning defect in hexagonal GeSb2Te4 by direct atomic‐scale imaging experiments is reported, which serves as the key ingredient to account for the abundance of inverted stacking faults in hexagonal GST and superlattices. Ab initio simulations reveal a low energy cost for these extended defects, and indicate that such defects can affect the electrical properties by inducing electron localization. This work provides additional insight into the nature and effects of structural disorder in GST phase‐change materials.
{"title":"In‐Plane Twinning Defects in Hexagonal GeSb2Te4","authors":"Jiangjing Wang, Han Zhang, Xudong Wang, Lu Lu, Chunlin Jia, Wei Zhang, R. Mazzarello","doi":"10.1002/admt.202200214","DOIUrl":"https://doi.org/10.1002/admt.202200214","url":null,"abstract":"Ge–Sb–Te (GST) alloys are an important family of phase‐change materials employed in non‐volatile memories and neuromorphic devices. Conventional memory cells based on GST rely on the switching between an amorphous state and a metastable, disordered rocksalt‐like phase. Recently, however, it has been proposed that a special type of defect in layer‐structured GST—the so called “swapped bilayer” defect—is responsible for a novel phase‐change mechanism observed in GST‐based superlattices. Thus, disorder appears to play an important role in both types of switching mechanisms. Here, the observation of a new in‐plane twinning defect in hexagonal GeSb2Te4 by direct atomic‐scale imaging experiments is reported, which serves as the key ingredient to account for the abundance of inverted stacking faults in hexagonal GST and superlattices. Ab initio simulations reveal a low energy cost for these extended defects, and indicate that such defects can affect the electrical properties by inducing electron localization. This work provides additional insight into the nature and effects of structural disorder in GST phase‐change materials.","PeriodicalId":7200,"journal":{"name":"Advanced Materials & Technologies","volume":"75 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-04-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72789675","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Harald Rupp, R. Bhandary, Amit Kulkarni, W. Binder
Here, the 3D‐printing of supramolecular polymer electrolytes is reported, able to be manufactured via 3D‐printing processes, additionally dynamically compensating for volume changes. A careful mechanical design, in addition to rheological effects observed for different additives to the electrolyte, is investigated and adjusted, in order to achieve printability via an extrusion process to generate a conductive electrode material. Qudruple‐hydrogen bonds (UPy) act as supramolecular entities for the desired dynamic properties to adjust printability, in addition to added LiTFSi‐salts to achieve ionic conductivities of ≈10–4 S cm–1 at T = 80 °C. Three different telechelic UPy‐PEO/PPO‐UPy‐polymers with molecular weights ranging from Mn = 600–1500 g mol−1 were investigated in view of their 3D‐printability by FDM‐processes. It is found that there are three effects counterbalancing the rheological properties of the polymers: besides temperatures, which can be used as a known tool to adjust melt‐rheology, also the addition of lithium‐salts in junction with the polymers crystallinity exerts a major toolbox to 3D‐print these electrolytes. Using specific compositions with Li/EO‐ratios from 20:1, 10:1, and 5:1, the rheological profile can be adjusted to reach the required printability window. AT‐IR‐investigations clearly indicate a weakening of the UPy‐bonds by the added Li+ ions, in addition to a reduction of the crystallinity of the PEO‐units, further changing the rheological profile. The so generated electrolytes are printable systems for novel electrolytes.
{"title":"Printable Electrolytes: Tuning 3D‐Printing by Multiple Hydrogen Bonds and Added Inorganic Lithium‐Salts","authors":"Harald Rupp, R. Bhandary, Amit Kulkarni, W. Binder","doi":"10.1002/admt.202200088","DOIUrl":"https://doi.org/10.1002/admt.202200088","url":null,"abstract":"Here, the 3D‐printing of supramolecular polymer electrolytes is reported, able to be manufactured via 3D‐printing processes, additionally dynamically compensating for volume changes. A careful mechanical design, in addition to rheological effects observed for different additives to the electrolyte, is investigated and adjusted, in order to achieve printability via an extrusion process to generate a conductive electrode material. Qudruple‐hydrogen bonds (UPy) act as supramolecular entities for the desired dynamic properties to adjust printability, in addition to added LiTFSi‐salts to achieve ionic conductivities of ≈10–4 S cm–1 at T = 80 °C. Three different telechelic UPy‐PEO/PPO‐UPy‐polymers with molecular weights ranging from Mn = 600–1500 g mol−1 were investigated in view of their 3D‐printability by FDM‐processes. It is found that there are three effects counterbalancing the rheological properties of the polymers: besides temperatures, which can be used as a known tool to adjust melt‐rheology, also the addition of lithium‐salts in junction with the polymers crystallinity exerts a major toolbox to 3D‐print these electrolytes. Using specific compositions with Li/EO‐ratios from 20:1, 10:1, and 5:1, the rheological profile can be adjusted to reach the required printability window. AT‐IR‐investigations clearly indicate a weakening of the UPy‐bonds by the added Li+ ions, in addition to a reduction of the crystallinity of the PEO‐units, further changing the rheological profile. The so generated electrolytes are printable systems for novel electrolytes.","PeriodicalId":7200,"journal":{"name":"Advanced Materials & Technologies","volume":"4 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-04-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81610290","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Y. Kornbluth, L. Parameswaran, R. Mathews, L. Racz, L. Velásquez-García
This study reports the first fully additively manufactured capacitors as a proof‐of‐concept demonstration of direct‐write, ultrathin‐film electronic components made via multi‐material microplasma sputtering. This is also the first demonstration of a cleanroom‐quality, multi‐material electrical device produced entirely through additive manufacturing. Ultrathin metal and dielectric films are deposited at <80 °C and atmospheric pressure conditions on a substrate using a novel, continuously fed, dual target microsputtering printhead. The conductive films are created by sputtering gold in an air atmosphere and shown to attain near‐bulk electrical resistivity. The dielectric films are created by sputtering aluminum in a gas blend of argon and air; the aluminum oxidizes in the high‐energy, high‐collisionality plasma, forming alumina nanoparticles that are deposited on the substrate. Ultra‐thin (35 nm) alumina films showed extremely high resistivity (100 GΩ‐m) and dielectric strength (6.2 GV m−1). Also, the frequency response of the capacitor is satisfactorily described by the universal dielectric response typically found in heterogenous dielectrics. It is hypothesized that the dielectric response is the result of the presence of condensed water in the pores of the alumina film.
{"title":"Fully 3D‐Printed, Ultrathin Capacitors via Multi‐Material Microsputtering","authors":"Y. Kornbluth, L. Parameswaran, R. Mathews, L. Racz, L. Velásquez-García","doi":"10.1002/admt.202200097","DOIUrl":"https://doi.org/10.1002/admt.202200097","url":null,"abstract":"This study reports the first fully additively manufactured capacitors as a proof‐of‐concept demonstration of direct‐write, ultrathin‐film electronic components made via multi‐material microplasma sputtering. This is also the first demonstration of a cleanroom‐quality, multi‐material electrical device produced entirely through additive manufacturing. Ultrathin metal and dielectric films are deposited at <80 °C and atmospheric pressure conditions on a substrate using a novel, continuously fed, dual target microsputtering printhead. The conductive films are created by sputtering gold in an air atmosphere and shown to attain near‐bulk electrical resistivity. The dielectric films are created by sputtering aluminum in a gas blend of argon and air; the aluminum oxidizes in the high‐energy, high‐collisionality plasma, forming alumina nanoparticles that are deposited on the substrate. Ultra‐thin (35 nm) alumina films showed extremely high resistivity (100 GΩ‐m) and dielectric strength (6.2 GV m−1). Also, the frequency response of the capacitor is satisfactorily described by the universal dielectric response typically found in heterogenous dielectrics. It is hypothesized that the dielectric response is the result of the presence of condensed water in the pores of the alumina film.","PeriodicalId":7200,"journal":{"name":"Advanced Materials & Technologies","volume":"203 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76200415","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Xichao Tan, Jinming Jian, Y. Qiao, Thomas Hirtz, Guanhua Dun, Yi‐Zhe Guo, Tianrui Cui, Jiandong Xu, Shourui Ji, Yi Yang, Tian-ling Ren
Despite extensive research on photoelectric sensors that typically output signals to indicate the transient ultraviolet (UV) intensity, developing wearable, electrometric photodetectors that can reveal the cumulative UV exposure remains challenging. Here, an organic–inorganic hybrid bulk heterojunction (BHJ) is used to construct a skin‐mimicking, wearable photodetector, based on conductive polymer sensitized with semiconducting nanoparticles. Owing to the UV‐induced reduction reactions, the BHJ photodetectors (PDs) can long remember the UV radiation previously exposed. Moreover, based on the solution processability of bulk heterojunction blends and rich surface functional groups of polydopamine, BHJ PDs can fully inherit the ultraflexibility from electrospun fiber‐networked structure. Thus, this fiber‐configured photodetector is working well even at the strains of up to 60%. Without requiring any complicated analytical tool, its memory effect and simple‐to‐process output facilitate the working mechanism of power‐free UV monitor, while catering to the individual need of different skin types. This work combines the bottom materials design to the top device application, pointing out a new direction in wearable UV sensor technologies.
{"title":"Skin‐Mimicking, Stretchable Photodetector for Skin‐Customized Ultraviolet Dosimetry","authors":"Xichao Tan, Jinming Jian, Y. Qiao, Thomas Hirtz, Guanhua Dun, Yi‐Zhe Guo, Tianrui Cui, Jiandong Xu, Shourui Ji, Yi Yang, Tian-ling Ren","doi":"10.1002/admt.202101348","DOIUrl":"https://doi.org/10.1002/admt.202101348","url":null,"abstract":"Despite extensive research on photoelectric sensors that typically output signals to indicate the transient ultraviolet (UV) intensity, developing wearable, electrometric photodetectors that can reveal the cumulative UV exposure remains challenging. Here, an organic–inorganic hybrid bulk heterojunction (BHJ) is used to construct a skin‐mimicking, wearable photodetector, based on conductive polymer sensitized with semiconducting nanoparticles. Owing to the UV‐induced reduction reactions, the BHJ photodetectors (PDs) can long remember the UV radiation previously exposed. Moreover, based on the solution processability of bulk heterojunction blends and rich surface functional groups of polydopamine, BHJ PDs can fully inherit the ultraflexibility from electrospun fiber‐networked structure. Thus, this fiber‐configured photodetector is working well even at the strains of up to 60%. Without requiring any complicated analytical tool, its memory effect and simple‐to‐process output facilitate the working mechanism of power‐free UV monitor, while catering to the individual need of different skin types. This work combines the bottom materials design to the top device application, pointing out a new direction in wearable UV sensor technologies.","PeriodicalId":7200,"journal":{"name":"Advanced Materials & Technologies","volume":"80 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78850325","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jian-Yu Wang, F. Jin, Xiangyuan Dong, Jie Liu, Meiling Zheng
With the development of bionics and nanophotonics, hydrogel microactuators capable of responding to external stimuli to produce controllable deformations have attracted a great deal of interest. These microactuators hold significant promise in areas such as bionic devices, soft robotics, and precision sensors. It is not a trivial task to make such small devices as well as to make them work in a controlled manner. Here, inspired by the intelligent response of flytrap, a smart hydrogel microactuator based on a bionic asymmetric structure is demonstrated. The designed asymmetric microstructure is fabricated by femtosecond laser direct writing with deformation time of 1.2 s and recovery time of 0.3 s. The grasping and releasing behavior of the microactuator for micro‐objects can be realized and tuned by using pH‐triggered shape changes, demonstrating its potential for applications, such as flexible robotics, smart sensors, and microscopic manipulation.
{"title":"Flytrap Inspired pH‐Driven 3D Hydrogel Actuator by Femtosecond Laser Microfabrication","authors":"Jian-Yu Wang, F. Jin, Xiangyuan Dong, Jie Liu, Meiling Zheng","doi":"10.1002/admt.202200276","DOIUrl":"https://doi.org/10.1002/admt.202200276","url":null,"abstract":"With the development of bionics and nanophotonics, hydrogel microactuators capable of responding to external stimuli to produce controllable deformations have attracted a great deal of interest. These microactuators hold significant promise in areas such as bionic devices, soft robotics, and precision sensors. It is not a trivial task to make such small devices as well as to make them work in a controlled manner. Here, inspired by the intelligent response of flytrap, a smart hydrogel microactuator based on a bionic asymmetric structure is demonstrated. The designed asymmetric microstructure is fabricated by femtosecond laser direct writing with deformation time of 1.2 s and recovery time of 0.3 s. The grasping and releasing behavior of the microactuator for micro‐objects can be realized and tuned by using pH‐triggered shape changes, demonstrating its potential for applications, such as flexible robotics, smart sensors, and microscopic manipulation.","PeriodicalId":7200,"journal":{"name":"Advanced Materials & Technologies","volume":"569 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73032182","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Xiaojing Cheng, S. Shen, G. Wei, Chao Wang, L. Luo, Junliang Zhang
The key to address the cost issue of polymer electrolyte membrane fuel cells (PEMFCs) lies on reducing Pt amount employed in cathode catalyst layers (CCLs). In past decades, researchers focus on developing series of alloy and core–shell electrocatalysts with high oxygen reduction reaction activity in order to alleviate the low Pt loading caused performance loss. However, it is noted that the concentration polarization loss resulting from the cathode oxygen transport plays a more important role as the Pt loading decreases, especially the local oxygen transport through the ultrathin ionomer film covering on Pt surface. This paper reviews the nanomorphology of the ultrathin perfluorinated sulfonic acid ionomer film in CCLs, as well as the local oxygen transport mechanism and the corresponding effects on fuel cell performance in low Pt PEMFCs. In addition, both the detailed local oxygen transport properties in carbon black‐supported Pt membrane electrode assemblies (MEAs) and high surface carbon‐supported MEAs are summarized. Subsequently, numerous innovative strategies and effective approaches of reducing the local oxygen transport resistance are introduced. The new insights proposed in this paper have important implications for enhancing local oxygen transport and designing high‐performance fuel cell electrodes.
{"title":"Perspectives on Challenges and Achievements in Local Oxygen Transport of Low Pt Proton Exchange Membrane Fuel Cells","authors":"Xiaojing Cheng, S. Shen, G. Wei, Chao Wang, L. Luo, Junliang Zhang","doi":"10.1002/admt.202200228","DOIUrl":"https://doi.org/10.1002/admt.202200228","url":null,"abstract":"The key to address the cost issue of polymer electrolyte membrane fuel cells (PEMFCs) lies on reducing Pt amount employed in cathode catalyst layers (CCLs). In past decades, researchers focus on developing series of alloy and core–shell electrocatalysts with high oxygen reduction reaction activity in order to alleviate the low Pt loading caused performance loss. However, it is noted that the concentration polarization loss resulting from the cathode oxygen transport plays a more important role as the Pt loading decreases, especially the local oxygen transport through the ultrathin ionomer film covering on Pt surface. This paper reviews the nanomorphology of the ultrathin perfluorinated sulfonic acid ionomer film in CCLs, as well as the local oxygen transport mechanism and the corresponding effects on fuel cell performance in low Pt PEMFCs. In addition, both the detailed local oxygen transport properties in carbon black‐supported Pt membrane electrode assemblies (MEAs) and high surface carbon‐supported MEAs are summarized. Subsequently, numerous innovative strategies and effective approaches of reducing the local oxygen transport resistance are introduced. The new insights proposed in this paper have important implications for enhancing local oxygen transport and designing high‐performance fuel cell electrodes.","PeriodicalId":7200,"journal":{"name":"Advanced Materials & Technologies","volume":"10 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81678703","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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