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}
Cameron M. Cole, Susanna V. Kunz, P. Shaw, C. S. K. Ranasinghe, Thomas Baumann, J. Blinco, P. Sonar, C. Barner‐Kowollik, S. Yambem
Thermally activated delayed fluorescent (TADF) materials are extensively investigated as organic light‐emitting diodes (OLEDs) with TADF emitting layers demonstrating high efficiency without the use of heavy metal complexes. Therefore, solution‐processable and printable TADF emitters are highly desirable, moving away from expensive vacuum deposition techniques. In addition, using emissive materials not requiring an external host simplifies the fabrication process significantly. Herein, OLEDs using a solution‐processable TADF polymer that do not need an external host are introduced. The non‐conjugated TADF polymer features a TADF emitter (4‐(9H‐carbazol‐9‐yl)‐2‐(3′‐hydroxy‐[1,1′‐biphenyl]‐3‐yl)‐isoindoline‐1,3‐dione) as a side chain, as well as a hole‐transporting side chain and an electron‐transporting side chain on an inactive polymer backbone. All organic layers of the OLEDs are fabricated using solution processing methods. The OLEDs with inkjet‐printed emissive layers have comparable maximum current and external quantum efficiency as their spin‐coated counterparts, exceeding luminance of 2000 cd m−2. The herein‐explored strategy is a viable route toward self‐hosted printable TADF OLEDs.
热激活延迟荧光(TADF)材料被广泛研究为有机发光二极管(oled)，具有TADF发射层，在不使用重金属配合物的情况下显示出高效率。因此，溶液可处理和可打印的TADF发射器是非常可取的，远离昂贵的真空沉积技术。此外，使用不需要外部主机的发射材料大大简化了制造过程。本文介绍了使用溶液可加工TADF聚合物的oled，该聚合物不需要外部主机。非共轭TADF聚合物具有TADF发射器(4‐(9H‐咔唑‐9‐基)‐2‐(3′‐羟基‐[1,1′‐联苯]‐3‐基)‐异吲哚啉‐1,3‐二酮)作为侧链，以及在非活性聚合物主链上的空穴传递侧链和电子传递侧链。oled的所有有机层都是用溶液加工方法制造的。喷墨印刷发光层的oled与自旋涂层的oled相比，具有相当的最大电流和外量子效率，亮度超过2000 cd m−2。本文探讨的策略是实现自托管可打印TADF oled的可行途径。
{"title":"Inkjet‐Printed Self‐Hosted TADF Polymer Light‐Emitting Diodes","authors":"Cameron M. Cole, Susanna V. Kunz, P. Shaw, C. S. K. Ranasinghe, Thomas Baumann, J. Blinco, P. Sonar, C. Barner‐Kowollik, S. Yambem","doi":"10.1002/admt.202200648","DOIUrl":"https://doi.org/10.1002/admt.202200648","url":null,"abstract":"Thermally activated delayed fluorescent (TADF) materials are extensively investigated as organic light‐emitting diodes (OLEDs) with TADF emitting layers demonstrating high efficiency without the use of heavy metal complexes. Therefore, solution‐processable and printable TADF emitters are highly desirable, moving away from expensive vacuum deposition techniques. In addition, using emissive materials not requiring an external host simplifies the fabrication process significantly. Herein, OLEDs using a solution‐processable TADF polymer that do not need an external host are introduced. The non‐conjugated TADF polymer features a TADF emitter (4‐(9H‐carbazol‐9‐yl)‐2‐(3′‐hydroxy‐[1,1′‐biphenyl]‐3‐yl)‐isoindoline‐1,3‐dione) as a side chain, as well as a hole‐transporting side chain and an electron‐transporting side chain on an inactive polymer backbone. All organic layers of the OLEDs are fabricated using solution processing methods. The OLEDs with inkjet‐printed emissive layers have comparable maximum current and external quantum efficiency as their spin‐coated counterparts, exceeding luminance of 2000 cd m−2. The herein‐explored strategy is a viable route toward self‐hosted printable TADF OLEDs.","PeriodicalId":7200,"journal":{"name":"Advanced Materials & Technologies","volume":"49 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88709035","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}
J. Jo, Artemis Xu, Anand Kumar Mishra, Hedan Bai, Armen Derkevorkian, J. Rabinovitch, Huiju Park, R. Shepherd
Conventional strain gauges are not designed for accurate measurement over the large range of deformations possible in compliant textiles. The thin, lightweight, and flexible nature of textiles also makes it challenging to attach strain gauges in a way that does not affect the mechanical properties. In this manuscript, soft, highly extensible fibers that propagate light (i.e., stretchable lightguides) are stitched as a strain gauge to map the deformation of a nylon parachute textile under tension. When under load, these fiber optic strain gauges propagate less light, and this strain‐induced light modulation is used to accurately (absolute error≈2.93%; Std. Dev.: 3.02%) measure strain in the <30% range before these textiles fail. This system has directionality; strain in parallel to the sensor results in little light attenuation while perpendicular loading shows high sensitivity (Gauge factor⊥≈24.8 and Gauge factor||≈0.05 at the first 1% strain). Structural and optical simulations are coupled to demonstrate that load transfer on the fiber optic by the stitchwork is the dominating cause of signal modulation. To further validate the hypotheses, digital image correlation was used under dynamic loading conditions to show that these sensors do not significantly affect the mechanical properties.
{"title":"Measurement of Parachute Canopy Textile Deformation Using Mechanically Invisible Stretchable Lightguides","authors":"J. Jo, Artemis Xu, Anand Kumar Mishra, Hedan Bai, Armen Derkevorkian, J. Rabinovitch, Huiju Park, R. Shepherd","doi":"10.1002/admt.202200437","DOIUrl":"https://doi.org/10.1002/admt.202200437","url":null,"abstract":"Conventional strain gauges are not designed for accurate measurement over the large range of deformations possible in compliant textiles. The thin, lightweight, and flexible nature of textiles also makes it challenging to attach strain gauges in a way that does not affect the mechanical properties. In this manuscript, soft, highly extensible fibers that propagate light (i.e., stretchable lightguides) are stitched as a strain gauge to map the deformation of a nylon parachute textile under tension. When under load, these fiber optic strain gauges propagate less light, and this strain‐induced light modulation is used to accurately (absolute error≈2.93%; Std. Dev.: 3.02%) measure strain in the <30% range before these textiles fail. This system has directionality; strain in parallel to the sensor results in little light attenuation while perpendicular loading shows high sensitivity (Gauge factor⊥≈24.8 and Gauge factor||≈0.05 at the first 1% strain). Structural and optical simulations are coupled to demonstrate that load transfer on the fiber optic by the stitchwork is the dominating cause of signal modulation. To further validate the hypotheses, digital image correlation was used under dynamic loading conditions to show that these sensors do not significantly affect the mechanical properties.","PeriodicalId":7200,"journal":{"name":"Advanced Materials & Technologies","volume":"34 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87355942","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}
Xue Wang, Pengfei Zhao, Y. Tong, Shanlei Guo, Guodong Zhao, Mingxin Zhang, Hongyan Yu, Xiaoli Zhao, Q. Tang, Yichun Liu
Reduced graphene oxide (rGO) electrodes are known to exhibit high transparency, excellent chemical stability, low‐cost solution processability, and good compatibility for use in solution‐processed organic transistors, but they face fundamental challenges in conductivity and conformability for skin‐like electronics. Here, by inserting a poly(3,4‐ethylenedioxythiophene):poly‐(styrenesulfonate) (PEDOT:PSS) layer, the photolithographic conformal rGO/PEDOT:PSS electrodes with conductivity as high as 2000 S cm−1 can be achieved. Simultaneously, the rGO/PEDOT:PSS hybrid electrodes exhibit high precision down to 1 µm, high transparency of >90% over the visible spectra (400–700 nm), and imperceptible adherence onto damselfly wing without affecting flying. The resulting all‐solution processed organic transistor array presents the enhanced modulation effect of the gate voltage on current, 5.5‐fold increased mobility, and the on‐state current increased by one order of magnitude compared with the neat rGO electrode device, and shows the good adherence to deforming human skins and stable operation on the 10 mm spherical surface with mobility as high as 2.33 cm2 V−1 s−1. The strategy provides a high‐precision, high‐integration, flexible pattern‐designable, and scalable route to produce the high‐conductive transparent conformal rGO/PEDOT:PSS hybrid electrodes for flexible skin‐like all solution‐processed organic transistor array, showing the outstanding potential for future low‐cost soft electronics.
还原氧化石墨烯(rGO)电极具有高透明度、优异的化学稳定性、低成本的溶液可加工性和溶液处理有机晶体管的良好兼容性，但它们在类皮肤电子产品的导电性和一致性方面面临着根本性的挑战。在这里，通过插入聚(3,4‐乙烯二氧噻吩):聚苯乙烯磺酸盐(PEDOT:PSS)层，可以实现电导率高达2000 S cm−1的光刻保形rGO/PEDOT:PSS电极。同时，rGO/PEDOT:PSS混合电极具有高精度至1 μ m，在可见光谱(400-700 nm)上具有>90%的高透明度，并且在不影响飞行的情况下难以察觉地粘附在豆娘翅膀上。所制备的全溶液处理有机晶体管阵列具有栅极电压对电流的调制效应增强，迁移率提高了5.5倍，导通电流比纯氧化石墨烯电极器件提高了一个数量级，并且对变形的人体皮肤具有良好的粘附性，在10 mm球面上稳定运行，迁移率高达2.33 cm2 V−1 s−1。该策略提供了一种高精度、高集成度、灵活模式可设计和可扩展的路线，用于生产高导电性透明共形rGO/PEDOT:PSS混合电极，用于柔性皮肤-像所有溶液处理的有机晶体管阵列，显示出未来低成本软电子产品的杰出潜力。
{"title":"Photolithographic High‐Conductivity Transparent Conformal rGO/PEDOT:PSS Electrodes for Flexible Skin‐Like All Solution‐Processed Organic Transistors","authors":"Xue Wang, Pengfei Zhao, Y. Tong, Shanlei Guo, Guodong Zhao, Mingxin Zhang, Hongyan Yu, Xiaoli Zhao, Q. Tang, Yichun Liu","doi":"10.1002/admt.202200660","DOIUrl":"https://doi.org/10.1002/admt.202200660","url":null,"abstract":"Reduced graphene oxide (rGO) electrodes are known to exhibit high transparency, excellent chemical stability, low‐cost solution processability, and good compatibility for use in solution‐processed organic transistors, but they face fundamental challenges in conductivity and conformability for skin‐like electronics. Here, by inserting a poly(3,4‐ethylenedioxythiophene):poly‐(styrenesulfonate) (PEDOT:PSS) layer, the photolithographic conformal rGO/PEDOT:PSS electrodes with conductivity as high as 2000 S cm−1 can be achieved. Simultaneously, the rGO/PEDOT:PSS hybrid electrodes exhibit high precision down to 1 µm, high transparency of >90% over the visible spectra (400–700 nm), and imperceptible adherence onto damselfly wing without affecting flying. The resulting all‐solution processed organic transistor array presents the enhanced modulation effect of the gate voltage on current, 5.5‐fold increased mobility, and the on‐state current increased by one order of magnitude compared with the neat rGO electrode device, and shows the good adherence to deforming human skins and stable operation on the 10 mm spherical surface with mobility as high as 2.33 cm2 V−1 s−1. The strategy provides a high‐precision, high‐integration, flexible pattern‐designable, and scalable route to produce the high‐conductive transparent conformal rGO/PEDOT:PSS hybrid electrodes for flexible skin‐like all solution‐processed organic transistor array, showing the outstanding potential for future low‐cost soft electronics.","PeriodicalId":7200,"journal":{"name":"Advanced Materials & Technologies","volume":"81 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87151855","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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