Pub Date : 2024-01-09DOI: 10.1088/2058-8585/ad1cce
Zhenhua Zhao, Yang Liu, Changzeng Ding, Wusong Zha, Qun Luo, Yinhua Zhou, Chang‐Qi Ma
Solution-processed top electrode is the key technology for the realization of fully solution-processed perovskite solar cells (PSCs). In this paper, we reported the preparation of fully-solution processed n-i-p type PSCs with spray-coated silver nanowires (AgNWs) top electrode. Experiment results demonstrated that low power conversion efficiency (PCE) of 16.00% with a low fill factor of 67.41% was obtained for the reference cell, when the AgNWs is directly coated on the 2,2′,7,7′-tetrakis(N,N-di-p-methoxyphenylamine)-9,9′-spirobifluorene (Spiro-OMeTAD) layer. This result indicates a charge extraction barrier at the Spiro-OMeTAD/AgNWs interface, which could be attributed to the poor compatibility between Spiro-OMeTAD and AgNWs layers. By inserting a thin layer of poly(3,4-ethylenedioxythiophene):perfluorinated sulfonic acid ionomers (PEDOT:F), a modified PEDOT with lower surface energy, the interface connection between Spiro-OMeTAD/PEDOT:F and AgNWs was improved, leading to an enhanced PCE of up to 19.11%. In addition, the PEDOT:F-based cells retained 64% of the initial PCE after operating at the maximum power point for 1800 hours, whereas the reference cells retained only 30% of the initial PCE. The current work proved that PEDOT:F/AgNWs could be an excellent option for fully-solution processed n-i-p type PSCs.
{"title":"Fully solution-processed n-i-p type perovskite solar cells with efficiency over 19% enabled by a hydrophobic PEDOT:F interlayer and silver nanowire top electrode","authors":"Zhenhua Zhao, Yang Liu, Changzeng Ding, Wusong Zha, Qun Luo, Yinhua Zhou, Chang‐Qi Ma","doi":"10.1088/2058-8585/ad1cce","DOIUrl":"https://doi.org/10.1088/2058-8585/ad1cce","url":null,"abstract":"\u0000 Solution-processed top electrode is the key technology for the realization of fully solution-processed perovskite solar cells (PSCs). In this paper, we reported the preparation of fully-solution processed n-i-p type PSCs with spray-coated silver nanowires (AgNWs) top electrode. Experiment results demonstrated that low power conversion efficiency (PCE) of 16.00% with a low fill factor of 67.41% was obtained for the reference cell, when the AgNWs is directly coated on the 2,2′,7,7′-tetrakis(N,N-di-p-methoxyphenylamine)-9,9′-spirobifluorene (Spiro-OMeTAD) layer. This result indicates a charge extraction barrier at the Spiro-OMeTAD/AgNWs interface, which could be attributed to the poor compatibility between Spiro-OMeTAD and AgNWs layers. By inserting a thin layer of poly(3,4-ethylenedioxythiophene):perfluorinated sulfonic acid ionomers (PEDOT:F), a modified PEDOT with lower surface energy, the interface connection between Spiro-OMeTAD/PEDOT:F and AgNWs was improved, leading to an enhanced PCE of up to 19.11%. In addition, the PEDOT:F-based cells retained 64% of the initial PCE after operating at the maximum power point for 1800 hours, whereas the reference cells retained only 30% of the initial PCE. The current work proved that PEDOT:F/AgNWs could be an excellent option for fully-solution processed n-i-p type PSCs.","PeriodicalId":51335,"journal":{"name":"Flexible and Printed Electronics","volume":"23 2","pages":""},"PeriodicalIF":3.1,"publicationDate":"2024-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139444233","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-01-09DOI: 10.1088/2058-8585/ad1ccf
Paria Naderi, Gerd Grau
Low-concentration deposition techniques such as inkjet printing for forming carbon nanotube (CNT) transistor channels typically result in higher on-off current ratio, while lowering the field-effect mobility compared to traditional high-concentration techniques. In this paper, we show that inkjet-printed devices can have both high field-effect mobility and on-off current ratio by utilizing coffee ring induced thickness variation in the channel. The coffee ring effect occurs naturally in printed patterns with most solvents and substrates, and it pushes dissolved particles to the edges of printed features. Thickness variation and coffee ring effect are usually avoided in the channel of solution processed TFTs by implementing additional expensive steps in the fabrication process. Instead, here, we control these variations and utilize them to create inkjet-printed CNT channels with printing induced thickness variation that improves transistor properties. Printing properties such as printing speed, and number of layers are studied to manipulate capillary flow and form thicker line edges, which ultimately enhance current transport in the CNT network. A two-pass printing pattern with separate lines improves the field-effect mobility five times compared to a pattern with connected lines that has no defined edges. The field-effect mobility increases from 1.1 to 5.7 cm2/V.s at a drain voltage of -2 V.
{"title":"Inkjet-Printed Transistors with Coffee Ring Aligned Carbon Nanotubes","authors":"Paria Naderi, Gerd Grau","doi":"10.1088/2058-8585/ad1ccf","DOIUrl":"https://doi.org/10.1088/2058-8585/ad1ccf","url":null,"abstract":"\u0000 Low-concentration deposition techniques such as inkjet printing for forming carbon nanotube (CNT) transistor channels typically result in higher on-off current ratio, while lowering the field-effect mobility compared to traditional high-concentration techniques. In this paper, we show that inkjet-printed devices can have both high field-effect mobility and on-off current ratio by utilizing coffee ring induced thickness variation in the channel. The coffee ring effect occurs naturally in printed patterns with most solvents and substrates, and it pushes dissolved particles to the edges of printed features. Thickness variation and coffee ring effect are usually avoided in the channel of solution processed TFTs by implementing additional expensive steps in the fabrication process. Instead, here, we control these variations and utilize them to create inkjet-printed CNT channels with printing induced thickness variation that improves transistor properties. Printing properties such as printing speed, and number of layers are studied to manipulate capillary flow and form thicker line edges, which ultimately enhance current transport in the CNT network. A two-pass printing pattern with separate lines improves the field-effect mobility five times compared to a pattern with connected lines that has no defined edges. The field-effect mobility increases from 1.1 to 5.7 cm2/V.s at a drain voltage of -2 V.","PeriodicalId":51335,"journal":{"name":"Flexible and Printed Electronics","volume":"40 23","pages":""},"PeriodicalIF":3.1,"publicationDate":"2024-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139442497","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-21DOI: 10.1088/2058-8585/ad0ea5
Mohamed Y Abdelatty, Ashraf Umar, Gurvinder S Khinda, Ryan J Cadwell, Joshua A Levy, Nancy Huang, Darshana L Weerawarne, Mohammed Alhendi, Scott M Miller, Mark D Poliks
Changes in the morphology and profile of the printed electronic traces affect the radio frequency (RF) performance, especially when compared to the simulated designs, which are primarily rectangular and smooth. The shape and morphology of the printed traces depend on the printing system, a combination of ink and substrate properties, and the printed technology used for fabrication. This paper investigates the significance of printing parameters like roughness, height, width, and profile shape on the RF performance of screen-printed traces statistically. This paper also derives a model based on actual profile shape and roughness measurements from incorporating these effects into the simulations. From the statistical study, we found that the role of surface roughness becomes more significant as the frequency increases. Thus, modeling surface roughness in flexible hybrid electronics simulations is fundamental for accurate results. Different simulated profile shapes also showed their effect on the RF performance, when combined with roughness, showed better correlation with experimental data. Our proposed model combines the modified Morgan and Hammerstad equation with the compound conductor model. Our proposed model uniquely integrates the modified Morgan and Hammerstad equation with the compound conductor model, leveraging a comprehensive approach focused on the quality and uniformity of printed electronics trace. This integration is aimed at constructing a model that is firmly grounded in actual roughness data, resulting in a solution that is both straightforward to implement and exceptionally accurate in its outcomes. The model agreed well with experimental measurement data over 7 GHz–40 GHz with a root-mean-square error average of 5.7%.
{"title":"The role of surface roughness on the electrical behavior of flexible and stretchable screen-printed silver ink on Kapton substrate","authors":"Mohamed Y Abdelatty, Ashraf Umar, Gurvinder S Khinda, Ryan J Cadwell, Joshua A Levy, Nancy Huang, Darshana L Weerawarne, Mohammed Alhendi, Scott M Miller, Mark D Poliks","doi":"10.1088/2058-8585/ad0ea5","DOIUrl":"https://doi.org/10.1088/2058-8585/ad0ea5","url":null,"abstract":"Changes in the morphology and profile of the printed electronic traces affect the radio frequency (RF) performance, especially when compared to the simulated designs, which are primarily rectangular and smooth. The shape and morphology of the printed traces depend on the printing system, a combination of ink and substrate properties, and the printed technology used for fabrication. This paper investigates the significance of printing parameters like roughness, height, width, and profile shape on the RF performance of screen-printed traces statistically. This paper also derives a model based on actual profile shape and roughness measurements from incorporating these effects into the simulations. From the statistical study, we found that the role of surface roughness becomes more significant as the frequency increases. Thus, modeling surface roughness in flexible hybrid electronics simulations is fundamental for accurate results. Different simulated profile shapes also showed their effect on the RF performance, when combined with roughness, showed better correlation with experimental data. Our proposed model combines the modified Morgan and Hammerstad equation with the compound conductor model. Our proposed model uniquely integrates the modified Morgan and Hammerstad equation with the compound conductor model, leveraging a comprehensive approach focused on the quality and uniformity of printed electronics trace. This integration is aimed at constructing a model that is firmly grounded in actual roughness data, resulting in a solution that is both straightforward to implement and exceptionally accurate in its outcomes. The model agreed well with experimental measurement data over 7 GHz–40 GHz with a root-mean-square error average of 5.7%.","PeriodicalId":51335,"journal":{"name":"Flexible and Printed Electronics","volume":"5 1","pages":""},"PeriodicalIF":3.1,"publicationDate":"2023-12-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139056607","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-19DOI: 10.1088/2058-8585/ad16ed
Dimitris Barmpakos, A. Apostolakis, Aggelos Pilatis, D. Pagonis, Grigoris Kaltsas
In recent years, there has been a growing interest in the development of flexible thermal flow sensing devices due to their wide-ranging applications. In this study, we present the fabrication of a screen-printed optical flow sensor on a 125 μm PET substrate in a three-layer configuration. The device comprises electrodes made from a commercial Ag ink, a heating area using a commercial carbon ink, and a thermochromic layer employing a commercial ink with a standard activation temperature of 31°C. We designed a specialized experimental setup to evaluate the performance of the optical flow sensor under static and dynamic conditions. To analyze the device's thermal response and performance across various flow conditions, we utilized a combination of electrical measurements and IR-optical imaging techniques. The all-printed device operates on the basis of a thermodynamic cycle frequency, which activates the thermochromic ink, causing it to blink at a frequency related to the flow passing over the sensor. The results of our preliminary testing are highly promising, as the sensor successfully demonstrated a clear relationship between flow and optical duty cycle. This innovative device offers a contactless, low-cost, easy-to-use flow detection method and holds significant potential for various practical applications.
近年来，由于柔性热流传感设备的广泛应用，人们对其开发的兴趣与日俱增。在本研究中，我们在 125 μm PET 基底上以三层结构制作了丝网印刷光流量传感器。该装置包括由商用银墨制成的电极、使用商用碳墨的加热区以及使用标准激活温度为 31°C 的商用墨水的热致变色层。我们设计了一个专门的实验装置来评估光学流量传感器在静态和动态条件下的性能。为了分析该装置在各种流动条件下的热响应和性能，我们结合使用了电学测量和红外光学成像技术。全印刷设备的工作基于热力学循环频率，该频率会激活热致变色油墨，使其按照与流过传感器的流量相关的频率闪烁。我们的初步测试结果很有希望，因为传感器成功证明了流量与光学占空比之间的明确关系。这种创新装置提供了一种非接触、低成本、易使用的流量检测方法，在各种实际应用中具有巨大潜力。
{"title":"A fully printed sensor with optical readout for real-time flow monitoring","authors":"Dimitris Barmpakos, A. Apostolakis, Aggelos Pilatis, D. Pagonis, Grigoris Kaltsas","doi":"10.1088/2058-8585/ad16ed","DOIUrl":"https://doi.org/10.1088/2058-8585/ad16ed","url":null,"abstract":"\u0000 In recent years, there has been a growing interest in the development of flexible thermal flow sensing devices due to their wide-ranging applications. In this study, we present the fabrication of a screen-printed optical flow sensor on a 125 μm PET substrate in a three-layer configuration. The device comprises electrodes made from a commercial Ag ink, a heating area using a commercial carbon ink, and a thermochromic layer employing a commercial ink with a standard activation temperature of 31°C. We designed a specialized experimental setup to evaluate the performance of the optical flow sensor under static and dynamic conditions. To analyze the device's thermal response and performance across various flow conditions, we utilized a combination of electrical measurements and IR-optical imaging techniques. The all-printed device operates on the basis of a thermodynamic cycle frequency, which activates the thermochromic ink, causing it to blink at a frequency related to the flow passing over the sensor. The results of our preliminary testing are highly promising, as the sensor successfully demonstrated a clear relationship between flow and optical duty cycle. This innovative device offers a contactless, low-cost, easy-to-use flow detection method and holds significant potential for various practical applications.","PeriodicalId":51335,"journal":{"name":"Flexible and Printed Electronics","volume":"9 16","pages":""},"PeriodicalIF":3.1,"publicationDate":"2023-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138959773","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-19DOI: 10.1088/2058-8585/ad16ee
Saurabh Sureda Joshi, Hocheon Yoo, Chang-Hyun Kim
Organic negative-transconductance (NTC) transistors are emerging as a new versatile element of flexible and printed electronics. However, there is no standard model of these transistors available in circuit simulators. This paper introduces the first current–voltage model for organic NTC transistors. The model reflects unique structural features of a state-of-the-art NTC transistor platform, incorporating a p-type, an n-type, and a back-conduction channel into a single heterojunction architecture. The details of modeling approach and development are systematically illustrated. Then, the model is firmly validated by experimental data from a high-performance device. Finally, controllability over the abruptness of inter-regime transitions is emphasized as a key advantage of the model for the accuracy of fitting results. This compact, closed-form, and analytical model covering all regimes of operation bridges the gap between device- and circuit-level perspective of organic NTC transistors, promoting their integration into practical electronics technologies.
{"title":"Modeling organic negative-transconductance transistors for circuit simulation","authors":"Saurabh Sureda Joshi, Hocheon Yoo, Chang-Hyun Kim","doi":"10.1088/2058-8585/ad16ee","DOIUrl":"https://doi.org/10.1088/2058-8585/ad16ee","url":null,"abstract":"\u0000 Organic negative-transconductance (NTC) transistors are emerging as a new versatile element of flexible and printed electronics. However, there is no standard model of these transistors available in circuit simulators. This paper introduces the first current–voltage model for organic NTC transistors. The model reflects unique structural features of a state-of-the-art NTC transistor platform, incorporating a p-type, an n-type, and a back-conduction channel into a single heterojunction architecture. The details of modeling approach and development are systematically illustrated. Then, the model is firmly validated by experimental data from a high-performance device. Finally, controllability over the abruptness of inter-regime transitions is emphasized as a key advantage of the model for the accuracy of fitting results. This compact, closed-form, and analytical model covering all regimes of operation bridges the gap between device- and circuit-level perspective of organic NTC transistors, promoting their integration into practical electronics technologies.","PeriodicalId":51335,"journal":{"name":"Flexible and Printed Electronics","volume":"117 50","pages":""},"PeriodicalIF":3.1,"publicationDate":"2023-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138958950","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-07DOI: 10.1088/2058-8585/ad0ebd
Ezgi Inci Yesilyurt, Jürgen Pionteck, Jari Keskinen, Aapo Kattainen, Timo Punkari, Frank Simon, Matti Mäntysalo, Brigitte Voit
Polyaniline (PANI)/carbide-derived carbon (CDC) was synthesized by using in-situ chemical oxidative polymerization of PANI in presence of CDC. Conductive electrode ink materials were prepared by using eco-friendly chitosan binder in water media. In the following, symmetrical supercapacitors (SCs) were fabricated by both doctor blade coating and screen printing technique. The electrical conductivity, morphology, specific capacitance, and energy density of these composites were evaluated for their applicability as SC electrodes. Pure PANI with chitosan binder was not printable because of its brittleness, however, the presence of CDC allows the preparation of smooth films which are suitable for electrode preparation. The fabricated composite electrode has a higher specific capacitance (up to 419 F g−1) and higher energy density (up to 6.7 W h kg−1) compared to the pristine CDC electrode. The capacitance of screen-printed SCs was 440–470 mF with an equivalent series resistance of about 27 Ω.
聚苯胺（PANI）/碳化物衍生碳（CDC）是在碳化物衍生碳存在的情况下利用原位化学氧化聚合法合成的。在水介质中使用环保型壳聚糖粘合剂制备了导电电极墨水材料。随后，利用刮刀涂层和丝网印刷技术制作了对称超级电容器（SC）。对这些复合材料的导电性、形态、比电容和能量密度进行了评估，以确定它们是否可用作超级电容器电极。含有壳聚糖粘合剂的纯 PANI 因其脆性而无法打印，但 CDC 的存在可以制备出适合电极制备的光滑薄膜。与原始 CDC 电极相比，制备的复合电极具有更高的比电容（高达 419 F g-1）和更高的能量密度（高达 6.7 W h kg-1）。丝网印刷 SC 的电容为 440-470 mF，等效串联电阻约为 27 Ω。
{"title":"Screen printable PANI/carbide-derived carbon supercapacitor electrode ink with chitosan binder","authors":"Ezgi Inci Yesilyurt, Jürgen Pionteck, Jari Keskinen, Aapo Kattainen, Timo Punkari, Frank Simon, Matti Mäntysalo, Brigitte Voit","doi":"10.1088/2058-8585/ad0ebd","DOIUrl":"https://doi.org/10.1088/2058-8585/ad0ebd","url":null,"abstract":"Polyaniline (PANI)/carbide-derived carbon (CDC) was synthesized by using <italic toggle=\"yes\">in-situ</italic> chemical oxidative polymerization of PANI in presence of CDC. Conductive electrode ink materials were prepared by using eco-friendly chitosan binder in water media. In the following, symmetrical supercapacitors (SCs) were fabricated by both doctor blade coating and screen printing technique. The electrical conductivity, morphology, specific capacitance, and energy density of these composites were evaluated for their applicability as SC electrodes. Pure PANI with chitosan binder was not printable because of its brittleness, however, the presence of CDC allows the preparation of smooth films which are suitable for electrode preparation. The fabricated composite electrode has a higher specific capacitance (up to 419 F g<sup>−1</sup>) and higher energy density (up to 6.7 W h kg<sup>−1</sup>) compared to the pristine CDC electrode. The capacitance of screen-printed SCs was 440–470 mF with an equivalent series resistance of about 27 Ω.","PeriodicalId":51335,"journal":{"name":"Flexible and Printed Electronics","volume":"33 1","pages":""},"PeriodicalIF":3.1,"publicationDate":"2023-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138686474","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-07DOI: 10.1088/2058-8585/ad1051
Nicholas Pratt, Pratap M Rao
Inkjet printing of electronic materials is of interest for digital printing of flexible electronics and sensors, but the width of the inkjet-printed lines is still large, limiting device size and performance. Decreasing the drop volume, increasing the drop spacing, and increasing the ink-substrate contact angle are all approaches by which the line width can be lowered, however these approaches are limited by the nozzle geometry, ink coalescence and bead instabilities, and contact angle hysteresis, respectively. Here we demonstrate a novel approach for stable inkjet printing of very narrow lines on ink-substrate combinations with a high contact angle, utilizing the de-wetting of the ink due to the decreased contact angle hysteresis. After printing and drying an initial layer of disconnected seed drops of silver nanoparticle ink, we print an additional layer of bridging drops of the same ink in between the dried seed drops. The bridging drops expand to touch the dried seed drops and then retract into a line, due to the pinning of the wet ink on the dried seed ink but not on the substrate, forming a continuous silver trace. The trace width is decreased from 60 μm with a traditional printing approach down to 12.6 μm with this seed-bridge approach. The electrical conductivity of the silver trace is similar to that of a conventionally printed trace. Due to poor adhesion on the print substrate, the trace was transferred to a separate polymer substrate with a simple hot-pressing procedure, which preserves the electrical conductivity of the trace.
{"title":"A seed and bridge layer method for inkjet printing of narrow traces on receding ink-substrate combinations","authors":"Nicholas Pratt, Pratap M Rao","doi":"10.1088/2058-8585/ad1051","DOIUrl":"https://doi.org/10.1088/2058-8585/ad1051","url":null,"abstract":"Inkjet printing of electronic materials is of interest for digital printing of flexible electronics and sensors, but the width of the inkjet-printed lines is still large, limiting device size and performance. Decreasing the drop volume, increasing the drop spacing, and increasing the ink-substrate contact angle are all approaches by which the line width can be lowered, however these approaches are limited by the nozzle geometry, ink coalescence and bead instabilities, and contact angle hysteresis, respectively. Here we demonstrate a novel approach for stable inkjet printing of very narrow lines on ink-substrate combinations with a high contact angle, utilizing the de-wetting of the ink due to the decreased contact angle hysteresis. After printing and drying an initial layer of disconnected seed drops of silver nanoparticle ink, we print an additional layer of bridging drops of the same ink in between the dried seed drops. The bridging drops expand to touch the dried seed drops and then retract into a line, due to the pinning of the wet ink on the dried seed ink but not on the substrate, forming a continuous silver trace. The trace width is decreased from 60 <italic toggle=\"yes\">μ</italic>m with a traditional printing approach down to 12.6 <italic toggle=\"yes\">μ</italic>m with this seed-bridge approach. The electrical conductivity of the silver trace is similar to that of a conventionally printed trace. Due to poor adhesion on the print substrate, the trace was transferred to a separate polymer substrate with a simple hot-pressing procedure, which preserves the electrical conductivity of the trace.","PeriodicalId":51335,"journal":{"name":"Flexible and Printed Electronics","volume":"33 1","pages":""},"PeriodicalIF":3.1,"publicationDate":"2023-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138686322","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-11-29DOI: 10.1088/2058-8585/ad0ea6
Zhifu Chen, Liangsong Huang, Peng Zhang, Yuxia Li, Xiaofei Bu, Huake Chen, Jiapeng Tan
Flexible strain sensors have stable and sensitive sensing performance under deformation conditions such as pressing, bending, and stretching. However, the preparation process of high-performance strain sensors is still very complex, which also limits the application and production of sensors. At the same time, most sensors are unstable and inefficient, so they cannot meet people’s expectations for high sensitivity and stability. In order to solve the above problems, this paper proposes a resistive strain sensor based on dispensing technology, with carbon black and polyurethane mixture as printing ink. Then, a sensor-sensitive layer with a right-angle serpentine structure is printed directly by air pressure extrusion. The sensor can detect changes at 0.1% strain and withstand 2400 tensile cycles while maintaining a sensitivity of 28.07 in the range of 0%–40%. In addition, the sensor can accurately and stably reflect the changes in different joints of the human body. At the same time, the data glove based on the strain sensor shows great application potential in the fields of gesture recognition and human–machine interaction.
{"title":"Highly sensitive strain sensors based on dispensing technology for human–machine interaction","authors":"Zhifu Chen, Liangsong Huang, Peng Zhang, Yuxia Li, Xiaofei Bu, Huake Chen, Jiapeng Tan","doi":"10.1088/2058-8585/ad0ea6","DOIUrl":"https://doi.org/10.1088/2058-8585/ad0ea6","url":null,"abstract":"Flexible strain sensors have stable and sensitive sensing performance under deformation conditions such as pressing, bending, and stretching. However, the preparation process of high-performance strain sensors is still very complex, which also limits the application and production of sensors. At the same time, most sensors are unstable and inefficient, so they cannot meet people’s expectations for high sensitivity and stability. In order to solve the above problems, this paper proposes a resistive strain sensor based on dispensing technology, with carbon black and polyurethane mixture as printing ink. Then, a sensor-sensitive layer with a right-angle serpentine structure is printed directly by air pressure extrusion. The sensor can detect changes at 0.1% strain and withstand 2400 tensile cycles while maintaining a sensitivity of 28.07 in the range of 0%–40%. In addition, the sensor can accurately and stably reflect the changes in different joints of the human body. At the same time, the data glove based on the strain sensor shows great application potential in the fields of gesture recognition and human–machine interaction.","PeriodicalId":51335,"journal":{"name":"Flexible and Printed Electronics","volume":"3 1","pages":""},"PeriodicalIF":3.1,"publicationDate":"2023-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138686396","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-11-07DOI: 10.1088/2058-8585/ad0a37
Hyeon-Soo Lee, Jun-Seok Ro, Gyu-Min Ko, Hea-Lim Park
Abstract Wearable neuromorphic devices have gained attention because of the growth in the Internet of Things and the increasing demand for health monitoring. They provide meaningful information and interact with the external environment through physiological signal processing and seamless interaction with the human body. The concept of these devices originated from the development of neuromorphic and flexible/stretchable electronics, which offer a solution to the limitation of conventional rigid devices. They have been developed to mimic synaptic functions and flexibility/stretchability of the biological nervous system. In this study, we described the various synaptic properties that should be implemented in synaptic devices and the operating mechanisms that exhibit these properties with respect to two- and three-terminal devices. Further, we specified comprehensive methods of implementing mechanical flexibility and stretchability in neuromorphic electronics through both structure and material engineering. In addition, we explored various wearable applications of these devices, such as wearable sensors for danger detection, auxiliary equipment for people with sensory disabilities, and neuroprosthetic devices. We expect this review to provide an overall understanding of concepts and trends for flexible and stretchable neuromorphic devices, with potential extensions to state-of-the-art applications such as cybernetics and exoskeleton.
{"title":"Flexible and stretchable synaptic devices for wearable neuromorphic electronics","authors":"Hyeon-Soo Lee, Jun-Seok Ro, Gyu-Min Ko, Hea-Lim Park","doi":"10.1088/2058-8585/ad0a37","DOIUrl":"https://doi.org/10.1088/2058-8585/ad0a37","url":null,"abstract":"Abstract Wearable neuromorphic devices have gained attention because of the growth in the Internet of Things and the increasing demand for health monitoring. They provide meaningful information and interact with the external environment through physiological signal processing and seamless interaction with the human body. The concept of these devices originated from the development of neuromorphic and flexible/stretchable electronics, which offer a solution to the limitation of conventional rigid devices. They have been developed to mimic synaptic functions and flexibility/stretchability of the biological nervous system. In this study, we described the various synaptic properties that should be implemented in synaptic devices and the operating mechanisms that exhibit these properties with respect to two- and three-terminal devices. Further, we specified comprehensive methods of implementing mechanical flexibility and stretchability in neuromorphic electronics through both structure and material engineering. In addition, we explored various wearable applications of these devices, such as wearable sensors for danger detection, auxiliary equipment for people with sensory disabilities, and neuroprosthetic devices. We expect this review to provide an overall understanding of concepts and trends for flexible and stretchable neuromorphic devices, with potential extensions to state-of-the-art applications such as cybernetics and exoskeleton.","PeriodicalId":51335,"journal":{"name":"Flexible and Printed Electronics","volume":"323 10","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135475171","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-11-01DOI: 10.1088/2058-8585/ad0658
Dan Feng, Neil Morrison, Claire Armstrong, Ken Moyers, Arvind Raman, Ryan Wagner
Abstract Web tension measurement and control are important for the quality control of flexible and printed electronics fabricated by roll-to-roll (R2R) manufacturing. The distribution of tension within a R2R web can be calculated from the values of the web’s mechanical resonance frequencies. Typically, such measurements require an active external forcing to be generated and applied to the web. In this work, we show it is possible to obtain the web’s resonance frequencies from forcing due to ambient noise present in the test environment. This result broadens the applicability of noncontact resonance methods for computing web tension as currently available methods of active external forcing cannot be applied to all web materials and all R2R operating environments. We validate the ambient excitation method by comparing it to speaker-based acoustic excitation at atmospheric pressure and find the two methods agree within 0.5%. A calculation of the experimental motion of the web due to finite temperature effects suggests the observed vibration is generated from air-borne or structure-borne noise in the test environments. To show the effectiveness of the approach, we demonstrate the use of ambient excitation at five externally applied tensions, on three different web materials, and at both atmospheric and vacuum pressures.
{"title":"Measurement of web tension using ambient vibrations in roll-to-roll manufacturing of flexible and printed electronics","authors":"Dan Feng, Neil Morrison, Claire Armstrong, Ken Moyers, Arvind Raman, Ryan Wagner","doi":"10.1088/2058-8585/ad0658","DOIUrl":"https://doi.org/10.1088/2058-8585/ad0658","url":null,"abstract":"Abstract Web tension measurement and control are important for the quality control of flexible and printed electronics fabricated by roll-to-roll (R2R) manufacturing. The distribution of tension within a R2R web can be calculated from the values of the web’s mechanical resonance frequencies. Typically, such measurements require an active external forcing to be generated and applied to the web. In this work, we show it is possible to obtain the web’s resonance frequencies from forcing due to ambient noise present in the test environment. This result broadens the applicability of noncontact resonance methods for computing web tension as currently available methods of active external forcing cannot be applied to all web materials and all R2R operating environments. We validate the ambient excitation method by comparing it to speaker-based acoustic excitation at atmospheric pressure and find the two methods agree within 0.5%. A calculation of the experimental motion of the web due to finite temperature effects suggests the observed vibration is generated from air-borne or structure-borne noise in the test environments. To show the effectiveness of the approach, we demonstrate the use of ambient excitation at five externally applied tensions, on three different web materials, and at both atmospheric and vacuum pressures.","PeriodicalId":51335,"journal":{"name":"Flexible and Printed Electronics","volume":"390 2","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135111608","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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