Christoph Pauer, Aron Venczel, Mihir Dass, T. Liedl, J. Tavacoli
Eukaryotic cells that swim by the beating of nanoscale elastic filaments (flagella) present a promising locomotion paradigm for man‐made analogues essential for next‐generation in‐vivo treatments and for the study of collective phenomena at the low Reynolds number limit. However, artificial analogues have been limited to many microns in size due to the engineering challenges of fabricating actable flexible filaments at the nanoscale—thereby narrowing the application scope. Here, made‐to‐order nanoscale filaments designed on the molecular level are fabricated using the DNA‐origami technique. It is found that magnetic beads anisotropically covered with such bundles move in a ballistic fashion when wagged back and forth under an external magnetic field. Furthermore, by comparing bead dynamics at a range of bundle coverages and driving frequencies, compelling evidence is amassed to suggest that this ballistic motion is imparted by the beating of the DNA origami filaments as synthetic flagella. This proof‐of‐concept work opens up avenues for further made‐for‐purpose appendages designed using DNA self‐assembly and with it ever more complex locomotion on the nano and microscale.
{"title":"Propulsion of Magnetic Beads Asymmetrically Covered with DNA Origami Appendages","authors":"Christoph Pauer, Aron Venczel, Mihir Dass, T. Liedl, J. Tavacoli","doi":"10.1002/admt.202200450","DOIUrl":"https://doi.org/10.1002/admt.202200450","url":null,"abstract":"Eukaryotic cells that swim by the beating of nanoscale elastic filaments (flagella) present a promising locomotion paradigm for man‐made analogues essential for next‐generation in‐vivo treatments and for the study of collective phenomena at the low Reynolds number limit. However, artificial analogues have been limited to many microns in size due to the engineering challenges of fabricating actable flexible filaments at the nanoscale—thereby narrowing the application scope. Here, made‐to‐order nanoscale filaments designed on the molecular level are fabricated using the DNA‐origami technique. It is found that magnetic beads anisotropically covered with such bundles move in a ballistic fashion when wagged back and forth under an external magnetic field. Furthermore, by comparing bead dynamics at a range of bundle coverages and driving frequencies, compelling evidence is amassed to suggest that this ballistic motion is imparted by the beating of the DNA origami filaments as synthetic flagella. This proof‐of‐concept work opens up avenues for further made‐for‐purpose appendages designed using DNA self‐assembly and with it ever more complex locomotion on the nano and microscale.","PeriodicalId":7200,"journal":{"name":"Advanced Materials & Technologies","volume":"38 4 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83017366","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}
Yongdong Wu, Qiangqiang Ma, Ting Liang, Yimin Yao, Junhong Li, Xiaoliang Zeng, Jian-bin Xu, Rong Sun
Aligned carbon nanotube (CNT) films with outstanding thermal and mechanical properties are promising for thermal management in electronics and mechanical enhancement in composites. One main challenge toward aligned CNT films is the loose stacking and unsatisfactory orientation of individual CNTs within the macroscopic assemblies, resulting in unsatisfactory performance. In this study, a facile strategy to densify commercial aligned CNT films with nearly doubled stacking density increasing from 0.63 to 1.17 g·cm−3, where the densification process involves infiltration of ethanol, CNT protonation along with mechanical stretching, is proposed. The densification strategy makes CNTs compactly aligned at the macro level, and enables CNTs to undergo spatial reorganization at the microscopic level simultaneously, contributing to a 125.9% and 680% enhancement of in‐plane thermal conductivity (357.1 W·m−1·K−1) and tensile strength (281.7 MPa) in densified CNT films, respectively. The densified CNT films also exhibit synchronous temperature variations with the heat source and excellent reliability in harsh environments, showing great potential in thermal management applications. This study provides effective route for driving commercial CNT films in thermal management, and contributes new ideas for the performance regulation of other carbon‐based macroscopic assemblies.
{"title":"A Facile Strategy to Densify Aligned CNT Films with Significantly Enhanced Thermal Conductivity and Mechanical Strength","authors":"Yongdong Wu, Qiangqiang Ma, Ting Liang, Yimin Yao, Junhong Li, Xiaoliang Zeng, Jian-bin Xu, Rong Sun","doi":"10.1002/admt.202200623","DOIUrl":"https://doi.org/10.1002/admt.202200623","url":null,"abstract":"Aligned carbon nanotube (CNT) films with outstanding thermal and mechanical properties are promising for thermal management in electronics and mechanical enhancement in composites. One main challenge toward aligned CNT films is the loose stacking and unsatisfactory orientation of individual CNTs within the macroscopic assemblies, resulting in unsatisfactory performance. In this study, a facile strategy to densify commercial aligned CNT films with nearly doubled stacking density increasing from 0.63 to 1.17 g·cm−3, where the densification process involves infiltration of ethanol, CNT protonation along with mechanical stretching, is proposed. The densification strategy makes CNTs compactly aligned at the macro level, and enables CNTs to undergo spatial reorganization at the microscopic level simultaneously, contributing to a 125.9% and 680% enhancement of in‐plane thermal conductivity (357.1 W·m−1·K−1) and tensile strength (281.7 MPa) in densified CNT films, respectively. The densified CNT films also exhibit synchronous temperature variations with the heat source and excellent reliability in harsh environments, showing great potential in thermal management applications. This study provides effective route for driving commercial CNT films in thermal management, and contributes new ideas for the performance regulation of other carbon‐based macroscopic assemblies.","PeriodicalId":7200,"journal":{"name":"Advanced Materials & Technologies","volume":"9 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75671780","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}
This work presents two different encapsulation strategies for perovskite photodetectors by testing the device stability under elevated ambient humidity of 85% and room temperature (25 °C). The single layer structure is adopted in the devices in order to accelerate the aging tests. The best stability (retention of ≈90% of initial photoresponsivity on average after 24 h, and ≈73% after 168 h) is obtained for devices protected by a flexible UV‐curable resin shell and encapsulated with AB epoxy including a desiccant sheet. The effects of the epoxy outgassing, the presence of desiccant, and the bending ability of encapsulated devices are also investigated. Additionally, with the assistance of 3D printing technology, a new possibility of research in the aspect of electrical device encapsulation is developed. Rapid iterative modifications in materials, shape, inner structure, and easy integration with outer component like desiccant ball/sheet make 3D printing assistance an ideal solution for the design of the encapsulation configuration and its early verification. This work not only opens up an optimal way for perovskite encapsulation by the 3D printing technology, but also provides an ideal solution for the design of the encapsulation configuration and its early verification.
{"title":"Novel 3D Printing Encapsulation Strategies for Perovskite Photodetectors","authors":"F. Zhao, Xiao Luo, Chenjie Gu, Jiamin Chen, Ziyang Hu, Yingquan Peng","doi":"10.1002/admt.202200521","DOIUrl":"https://doi.org/10.1002/admt.202200521","url":null,"abstract":"This work presents two different encapsulation strategies for perovskite photodetectors by testing the device stability under elevated ambient humidity of 85% and room temperature (25 °C). The single layer structure is adopted in the devices in order to accelerate the aging tests. The best stability (retention of ≈90% of initial photoresponsivity on average after 24 h, and ≈73% after 168 h) is obtained for devices protected by a flexible UV‐curable resin shell and encapsulated with AB epoxy including a desiccant sheet. The effects of the epoxy outgassing, the presence of desiccant, and the bending ability of encapsulated devices are also investigated. Additionally, with the assistance of 3D printing technology, a new possibility of research in the aspect of electrical device encapsulation is developed. Rapid iterative modifications in materials, shape, inner structure, and easy integration with outer component like desiccant ball/sheet make 3D printing assistance an ideal solution for the design of the encapsulation configuration and its early verification. This work not only opens up an optimal way for perovskite encapsulation by the 3D printing technology, but also provides an ideal solution for the design of the encapsulation configuration and its early verification.","PeriodicalId":7200,"journal":{"name":"Advanced Materials & Technologies","volume":"61 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85425005","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}
The mechanoreceptors of the human tactile sensory system contribute to natural grasping manipulations in everyday life. However, in the case of robot systems, attempts to emulate humans’ dexterity are still limited by tactile sensory feedback. In this work, a soft optical lightguide is applied as an afferent nerve fiber in a tactile sensory system. A skin‐like soft silicone material is combined with a bristle friction model, which is capable of fast and easy fabrication. Due to this novel design, the soft sensor can provide not only normal force (up to 5 Newtons) but also lateral force information generated by stick‐slip processes. Through a static force test and slip motion test, its ability to measure normal forces and to detect stick‐slip events is demonstrated. Finally, using a robotic gripper, real‐time control applications are investigated where the sensor helps the gripper apply sufficient force to grasp objects without slipping.
{"title":"Soft, All‐Polymer Optoelectronic Tactile Sensor for Stick‐Slip Detection","authors":"M. Han, C. Harnett","doi":"10.1002/admt.202200406","DOIUrl":"https://doi.org/10.1002/admt.202200406","url":null,"abstract":"The mechanoreceptors of the human tactile sensory system contribute to natural grasping manipulations in everyday life. However, in the case of robot systems, attempts to emulate humans’ dexterity are still limited by tactile sensory feedback. In this work, a soft optical lightguide is applied as an afferent nerve fiber in a tactile sensory system. A skin‐like soft silicone material is combined with a bristle friction model, which is capable of fast and easy fabrication. Due to this novel design, the soft sensor can provide not only normal force (up to 5 Newtons) but also lateral force information generated by stick‐slip processes. Through a static force test and slip motion test, its ability to measure normal forces and to detect stick‐slip events is demonstrated. Finally, using a robotic gripper, real‐time control applications are investigated where the sensor helps the gripper apply sufficient force to grasp objects without slipping.","PeriodicalId":7200,"journal":{"name":"Advanced Materials & Technologies","volume":"120 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80418295","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}
H. Vanduffel, C. Parra-Cabrera, W. Gsell, R. Oliveira-Silva, L. Goossens, R. Peeters, U. Himmelreich, B. Van Hooreweder, Dimitrios Sakellariou, W. Vanduffel, R. Ameloot
High signal‐to‐noise ratio (SNR) is crucial to obtaining high‐quality magnetic resonance (MR) images. However, a poor fit of fixed‐size radiofrequency (RF) coils to the subject often limits the SNR both in research and clinical magnetic resonance imaging (MRI) practice. Therefore, there is an urgent need to fabricate RF coils that exhibit a close geometrical fit (or are subject conformal) to the to‐be‐imaged region. A range of 3D printing methods are proposed for producing such conformal coils and overcoming constraints in geometrical complexity, production time, and cost. Laser powder bed fusion and stereolithography‐based methods are explored. The fully digital workflow allows for the seamless integration of electromagnetic simulations of geometrically complex coils, resulting in rapid design iterations. SNR gains up to 68% are observed for single 3D‐printed subject‐conformal coils compared to a state‐of‐the‐art commercially available (nonconformal) coil array. In addition to tests on phantoms, a conformal 3D‐printed coil is used to image the metacarpophalangeal joint of the thumb from a volunteer on an MRI scanner to demonstrate the improved image quality.
{"title":"Additive Manufacturing of Subject‐Conformal Receive Coils for Magnetic Resonance Imaging","authors":"H. Vanduffel, C. Parra-Cabrera, W. Gsell, R. Oliveira-Silva, L. Goossens, R. Peeters, U. Himmelreich, B. Van Hooreweder, Dimitrios Sakellariou, W. Vanduffel, R. Ameloot","doi":"10.1002/admt.202200647","DOIUrl":"https://doi.org/10.1002/admt.202200647","url":null,"abstract":"High signal‐to‐noise ratio (SNR) is crucial to obtaining high‐quality magnetic resonance (MR) images. However, a poor fit of fixed‐size radiofrequency (RF) coils to the subject often limits the SNR both in research and clinical magnetic resonance imaging (MRI) practice. Therefore, there is an urgent need to fabricate RF coils that exhibit a close geometrical fit (or are subject conformal) to the to‐be‐imaged region. A range of 3D printing methods are proposed for producing such conformal coils and overcoming constraints in geometrical complexity, production time, and cost. Laser powder bed fusion and stereolithography‐based methods are explored. The fully digital workflow allows for the seamless integration of electromagnetic simulations of geometrically complex coils, resulting in rapid design iterations. SNR gains up to 68% are observed for single 3D‐printed subject‐conformal coils compared to a state‐of‐the‐art commercially available (nonconformal) coil array. In addition to tests on phantoms, a conformal 3D‐printed coil is used to image the metacarpophalangeal joint of the thumb from a volunteer on an MRI scanner to demonstrate the improved image quality.","PeriodicalId":7200,"journal":{"name":"Advanced Materials & Technologies","volume":"59 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73719849","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}
Ubiquitous environmental energy has become an important energy source for ensuring long‐lasting operation of unattended monitoring systems. However, several technical bottlenecks remain for achieving improved collection performance of environmental energy. Herein, a transparent composite film comprising micro‐pyramid arrays (mp‐arrays) and a conductive ionic liquid (IL) based on polydimethylsiloxane (PDMS) is innovatively generated as a difunctional layer that acts as an antireflective coating for solar cells and an enhanced triboelectric layer for the raindrop‐harvesting triboelectric nanogenerator (RH‐TENG). The regular mp‐arrays fabricated using the template transfer technology according to the matched refractive index between IL and PDMS effectively inhibit the surface reflection and improve the light trapping ability of solar cells. Owing to a significant increase in transmittance, the power conversion efficiency of the solar cell is enhanced by 10.92% owing to the IL@PDMS coating with mp‐arrays (mp‐IL@PDMS). Further, the conductive IL significantly improves the dielectricity of PDMS film. Due to the improved dielectric constant, increased aspect ratio, and excellent hydrophobicity, the output voltage and current of the RH‐TENG with mp‐IL@PDMS are enhanced by ≈24‐ and 44‐fold, respectively. Overall, this study, which is based on the incorporation of transparent conductive IL, provides a new technical path for efficient multiclimate energy harvesting.
{"title":"Dual‐Enhanced Effect of Ionic Liquid Incorporation on Improving Hybrid Harvesting Properties of Solar and Raindrop Energy","authors":"Jinsha Song, Jiliang Mu, Zhengyang Li, Chengpeng Feng, Wenping Geng, Xiaojuan Hou, Jian He, Xiu-jian Chou","doi":"10.1002/admt.202200664","DOIUrl":"https://doi.org/10.1002/admt.202200664","url":null,"abstract":"Ubiquitous environmental energy has become an important energy source for ensuring long‐lasting operation of unattended monitoring systems. However, several technical bottlenecks remain for achieving improved collection performance of environmental energy. Herein, a transparent composite film comprising micro‐pyramid arrays (mp‐arrays) and a conductive ionic liquid (IL) based on polydimethylsiloxane (PDMS) is innovatively generated as a difunctional layer that acts as an antireflective coating for solar cells and an enhanced triboelectric layer for the raindrop‐harvesting triboelectric nanogenerator (RH‐TENG). The regular mp‐arrays fabricated using the template transfer technology according to the matched refractive index between IL and PDMS effectively inhibit the surface reflection and improve the light trapping ability of solar cells. Owing to a significant increase in transmittance, the power conversion efficiency of the solar cell is enhanced by 10.92% owing to the IL@PDMS coating with mp‐arrays (mp‐IL@PDMS). Further, the conductive IL significantly improves the dielectricity of PDMS film. Due to the improved dielectric constant, increased aspect ratio, and excellent hydrophobicity, the output voltage and current of the RH‐TENG with mp‐IL@PDMS are enhanced by ≈24‐ and 44‐fold, respectively. Overall, this study, which is based on the incorporation of transparent conductive IL, provides a new technical path for efficient multiclimate energy harvesting.","PeriodicalId":7200,"journal":{"name":"Advanced Materials & Technologies","volume":"6 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75806479","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}
A piezoelectric tactile sensor is beneficial for creating a self‐powered system with a compact design, which is essential in electronic‐skin technology. However, piezoelectricity is only capable of dynamic pressure detection because it responds to sudden environmental changes. Since it is common to add another sensing unit to detect static pressure that accompanies bulkiness, including a measuring apparatus, we demonstrate a self‐powered, single‐mode piezoelectric tactile sensor by fabricating a piezoelectric gel through the electrospinning technique. As piezoelectricity senses the dynamic pressure without an external power supply, ions detect the static pressure by maintaining the potential difference upon sustained pressure. Since each component outputs a voltage signal of the same type but different profiles upon pressure, it is possible to distinguish dynamic and static pressure in a single mode. Moreover, inspired by the sensory adaptation of mammalian skin, an ion‐assisted piezoelectric tactile sensor efficiently detects concurrently stacked stimuli by decreasing the output signal for sustained stimuli. The sensitivity for superimposed pressure upon initial 14.7 kPa increases by more than four times compared to that without sensory adaptation for both dynamic and static pressure.
{"title":"A Self‐Powered, Single‐Mode Tactile Sensor Based on Sensory Adaptation Using Piezoelectric‐Driven Ion Migration","authors":"Ey-In Lee, Jin‐Woo Park","doi":"10.1002/admt.202200691","DOIUrl":"https://doi.org/10.1002/admt.202200691","url":null,"abstract":"A piezoelectric tactile sensor is beneficial for creating a self‐powered system with a compact design, which is essential in electronic‐skin technology. However, piezoelectricity is only capable of dynamic pressure detection because it responds to sudden environmental changes. Since it is common to add another sensing unit to detect static pressure that accompanies bulkiness, including a measuring apparatus, we demonstrate a self‐powered, single‐mode piezoelectric tactile sensor by fabricating a piezoelectric gel through the electrospinning technique. As piezoelectricity senses the dynamic pressure without an external power supply, ions detect the static pressure by maintaining the potential difference upon sustained pressure. Since each component outputs a voltage signal of the same type but different profiles upon pressure, it is possible to distinguish dynamic and static pressure in a single mode. Moreover, inspired by the sensory adaptation of mammalian skin, an ion‐assisted piezoelectric tactile sensor efficiently detects concurrently stacked stimuli by decreasing the output signal for sustained stimuli. The sensitivity for superimposed pressure upon initial 14.7 kPa increases by more than four times compared to that without sensory adaptation for both dynamic and static pressure.","PeriodicalId":7200,"journal":{"name":"Advanced Materials & Technologies","volume":"115 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81857245","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}
Hangjie Jiang, Liyan Chen, Xianhui Wu, Zhaohua Luo, Ruiyang Li, Yongfu Liu, Zehua Liu, Peng Sun, W. You, Jun Jiang
The near‐infrared (NIR) phosphor‐converted light‐emitting diode (pc‐LED) is a new NIR light source with both compact structure and high efficiency, and its performances is greatly depended on the NIR phosphors. Herein, this work presents a Cr3+‐doped gadolinium aluminum gallium garnet (GAGG:Cr3+) NIR ceramic phosphor with a broadband emission in the range of 650–850 nm, and optical performances that can be regulated via crystal‐field engineering. By optimizing the Al/Ga ratio, an external quantum efficiency as high as 65% is observed. The thermal stability is enhanced with the increase of Al content, which is attributed to the broadening of bandgap and the weakening of electron–phonon coupling effect. The NIR light output powers of the fabricated device based on the GAGG:Cr3+ ceramic are up to 88.9 mW @ 10 mA and 1247.7 mW @ 200 mA, while the electro‐optical conversion efficiencies were 28.5% @ 10 mA and 17.7% @ 200 mA, respectively. In addition, the NIR pc‐LED exhibited a strong penetrability such that the veins in a palm could be clearly identified, allowing for its potential use in biosecurity applications.
{"title":"Spectral Regulation and Efficiency Optimization in Cr3+‐Doped Gadolinium Aluminum Gallium Garnet Near‐Infrared Ceramic Phosphors via Crystal‐Field Engineering","authors":"Hangjie Jiang, Liyan Chen, Xianhui Wu, Zhaohua Luo, Ruiyang Li, Yongfu Liu, Zehua Liu, Peng Sun, W. You, Jun Jiang","doi":"10.1002/admt.202200519","DOIUrl":"https://doi.org/10.1002/admt.202200519","url":null,"abstract":"The near‐infrared (NIR) phosphor‐converted light‐emitting diode (pc‐LED) is a new NIR light source with both compact structure and high efficiency, and its performances is greatly depended on the NIR phosphors. Herein, this work presents a Cr3+‐doped gadolinium aluminum gallium garnet (GAGG:Cr3+) NIR ceramic phosphor with a broadband emission in the range of 650–850 nm, and optical performances that can be regulated via crystal‐field engineering. By optimizing the Al/Ga ratio, an external quantum efficiency as high as 65% is observed. The thermal stability is enhanced with the increase of Al content, which is attributed to the broadening of bandgap and the weakening of electron–phonon coupling effect. The NIR light output powers of the fabricated device based on the GAGG:Cr3+ ceramic are up to 88.9 mW @ 10 mA and 1247.7 mW @ 200 mA, while the electro‐optical conversion efficiencies were 28.5% @ 10 mA and 17.7% @ 200 mA, respectively. In addition, the NIR pc‐LED exhibited a strong penetrability such that the veins in a palm could be clearly identified, allowing for its potential use in biosecurity applications.","PeriodicalId":7200,"journal":{"name":"Advanced Materials & Technologies","volume":"16 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89673820","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}
Wenqing Wang, M. O. G. Nayeem, Haoyang Wang, Chunya Wang, Jae Joon Kim, Binghao Wang, Sunghoon Lee, T. Yokota, T. Someya
On‐skin humidity sensors can be used to measure the sweat rate on the human skin surface. However, it is challenging to realize a precise, long‐term skin humidity measurement. The main challenge is to develop an on‐skin humidity sensor that has gas permeability, high sensitivity, and flexibility simultaneously. Porous materials and electrodes can enhance the properties of the humidity sensor for fulfilling continuous monitoring. Herein, a humidity sensor composed of nanomesh Au electrodes and nanomesh humidity‐sensitive materials, is reported. The porous structure makes the sensor flexible and gas permeable, increases the surface area, and leads to high sensitivity. The sensor has a high sensitivity of 640 000% in the relative‐humidity range of over 40–100%, together with a gas permeability similar to that of an open environment. The gas permeability suppresses the skin inflammation, endows natural evaporation of sweat, and brings an identical condition with bare skin. To evaluate the utility of the nanomesh sensor, on‐skin humidity measurements are performed, and the humidity change due to sweating after exercise is recorded.
{"title":"Gas‐Permeable Highly Sensitive Nanomesh Humidity Sensor for Continuous Measurement of Skin Humidity","authors":"Wenqing Wang, M. O. G. Nayeem, Haoyang Wang, Chunya Wang, Jae Joon Kim, Binghao Wang, Sunghoon Lee, T. Yokota, T. Someya","doi":"10.1002/admt.202200479","DOIUrl":"https://doi.org/10.1002/admt.202200479","url":null,"abstract":"On‐skin humidity sensors can be used to measure the sweat rate on the human skin surface. However, it is challenging to realize a precise, long‐term skin humidity measurement. The main challenge is to develop an on‐skin humidity sensor that has gas permeability, high sensitivity, and flexibility simultaneously. Porous materials and electrodes can enhance the properties of the humidity sensor for fulfilling continuous monitoring. Herein, a humidity sensor composed of nanomesh Au electrodes and nanomesh humidity‐sensitive materials, is reported. The porous structure makes the sensor flexible and gas permeable, increases the surface area, and leads to high sensitivity. The sensor has a high sensitivity of 640 000% in the relative‐humidity range of over 40–100%, together with a gas permeability similar to that of an open environment. The gas permeability suppresses the skin inflammation, endows natural evaporation of sweat, and brings an identical condition with bare skin. To evaluate the utility of the nanomesh sensor, on‐skin humidity measurements are performed, and the humidity change due to sweating after exercise is recorded.","PeriodicalId":7200,"journal":{"name":"Advanced Materials & Technologies","volume":"134 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89208235","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}
To avoid disastrous consequences from ice deposition, solar anti‐icing surfaces (SASs) have performed the potential of anti‐icing application because of their excellent photothermal de‐icing effect in the daytime. However, the deposition of ice still cannot be prevented due to the lack of solar energy at cold night, inevitably requiring extra energy consumption such as electrical heating. In this work, a bio‐inspired anti‐icing material (BAM) is presented, showing an energy‐saving design for sustainable ice repellency. By integrating a phase change microcapsule (PCM) layer with a superhydrophobic photothermal (SPT) layer, the BAM can delay icing for more than 8 h at cold night without any external energy. Different from traditional SASs, the PCM layer can store energy in the daytime and release heat energy for keeping temperature up freezing point at night. In addition, the SPT layer displays excellent solar‐to‐heat conversion for sufficient energy and robust self‐cleaning property for avoiding the blockage of sunlight from the contaminants or molten water, thereby resulting in the excellent icing delay. Therefore, this design can be developed and utilized for sustainable ice repellent applications such as power transmission, building infrastructure, and transportation networks.
{"title":"Bio‐Inspired Anti‐Icing Material as an Energy‐Saving Design toward Sustainable Ice Repellency","authors":"Hui Yang, Zhanhui Wang, Si-Cong Tan, Ruhua Zang, Cunyi Li, Zhiyuan He, Jingxin Meng, Shutao Wang, Jianjun Wang","doi":"10.1002/admt.202200502","DOIUrl":"https://doi.org/10.1002/admt.202200502","url":null,"abstract":"To avoid disastrous consequences from ice deposition, solar anti‐icing surfaces (SASs) have performed the potential of anti‐icing application because of their excellent photothermal de‐icing effect in the daytime. However, the deposition of ice still cannot be prevented due to the lack of solar energy at cold night, inevitably requiring extra energy consumption such as electrical heating. In this work, a bio‐inspired anti‐icing material (BAM) is presented, showing an energy‐saving design for sustainable ice repellency. By integrating a phase change microcapsule (PCM) layer with a superhydrophobic photothermal (SPT) layer, the BAM can delay icing for more than 8 h at cold night without any external energy. Different from traditional SASs, the PCM layer can store energy in the daytime and release heat energy for keeping temperature up freezing point at night. In addition, the SPT layer displays excellent solar‐to‐heat conversion for sufficient energy and robust self‐cleaning property for avoiding the blockage of sunlight from the contaminants or molten water, thereby resulting in the excellent icing delay. Therefore, this design can be developed and utilized for sustainable ice repellent applications such as power transmission, building infrastructure, and transportation networks.","PeriodicalId":7200,"journal":{"name":"Advanced Materials & Technologies","volume":"13 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91393468","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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