| 1. |
- Xin, Zhiging, et al.
(författare)
-
Scalable Fabrication of Conductive Lines by Patterned Wettability-Assisted Bar-Coating for Low Cost Paper-Based Circuits
- 2019
-
Ingår i: Advanced Materials Interfaces. - : Wiley-VCH Verlag. - 2196-7350. ; 6:10
-
Tidskriftsartikel (refereegranskat)abstract
- Patterning technology on the paper based on wettability difference for paper-based devices has attracted significant attention for its low cost, easy degradability, and high flexibility. Here, conductive lines are rapidly prepared by patterned wettability-assisted bar-coating for low cost paper-based circuits. It is found that 7 s plasma treatment time for acquiring wettability difference is optimal, which resulted in not only effective splitting of the liquid film but also highly consistent line width with mask. Moreover, low retention force of hydrophobic surface is imperative for self-confinement of the ink into hydrophilic areas, especially for ink with high solid content. The sheet resistance of patterns can reach 5 Ω ◻ −1 after 980 nm laser sintering when using 50 wt% solid content ink with 110 cP viscosity. The geometries of line patterns, i.e., line width and spacing, can be readily tuned by varying the designed size of mask patterns. As-prepared conductive patterns show good conductivity even after 500 bending cycles at 2 mm bending radius. It is believed that this study will provide deeper understanding of wettability difference-assisted patterning process and represents a general strategy for selective wetting, especially for high viscosity ink.
|
|
| 2. |
- Mo, Lixin, et al.
(författare)
-
Nano-Silver Ink of High Conductivity and Low Sintering Temperature for Paper Electronics
- 2019
-
Ingår i: Nanoscale Research Letters. - : Springer New York LLC. - 1931-7573 .- 1556-276X. ; 14
-
Tidskriftsartikel (refereegranskat)abstract
- Highly conductive ink with low sintering temperature is important for printed electronics on paper substrate. Silver nanoparticles (Ag NPs) of different average radii ranging from 48 to 176 nm were synthesized by adjusting the Ag+ concentration in the reaction process. The electric resistivity of the Ag NP-based ink film in relation to Ag NP size, sintering temperature, amount of PVP capping agent on Ag NP surface, and morphology evolution of the film during heating process was investigated. It was found that the resistivity of the films reduced very rapidly with increasing particle size due above all to reduced amount of protective agent capping on the Ag NPs. A semi-empirical relationship between the resistivity and the particle size was proposed. With the help of this mathematical expression, one gains both systematic and detailed insight to the resistivity evaluation with regard to the Ag particle size. The optimal electric resistivity of 4.6 μΩ cm was achieved at 140 °C for 10 min which was very close to the resistivity value of bulk Ag (1.58 μΩ cm). Mechanical flexibility of the printed electronics with the Ag NP-based ink on paper substrates was investigated. The prints on the art coated paper exhibited better flexibility compared to that on the photopaper. This might be attributed to the surface coating composition, surface morphology of the paper, and their corresponding ink absorption property. © 2019, The Author(s).
|
|
| 3. |
- Mo, Lixin, et al.
(författare)
-
Flexible transparent conductive films combining flexographic printed silver grids with CNT coating
- 2016
-
Ingår i: Nanotechnology. - : IOP Publishing. - 0957-4484 .- 1361-6528. ; 27:6
-
Tidskriftsartikel (refereegranskat)abstract
- A high-performance ITO-free transparent conductive film (TCF) has been made by combining high resolution Ag grids with a carbon nanotube (CNT) coating. Ag grids printed with flexography have a 20 Όm line width at a grid interval of 400 Όm. The Ag grid/CNT hybrid film exhibits excellent overall performance, with a typical sheet resistance of 14.8 Ω/□ and 82.6% light transmittance at room temperature. This means a 23.98% reduction in sheet resistance and only 2.52% loss in transmittance compared to a pure Ag grid film. Analysis indicates that filling areas between the Ag grids and interconnecting the silver nanoparticles with the CNT coating are the primary reasons for the significantly improved conductivity of the hybrid film that also exhibits excellent flexibility and mechanical strength compared to an ITO film. The hybrid film may fully satisfy the requirements of different applications, e.g. use as the anode of polymer solar cells (PSCs). The J-V curve shows that the power conversion efficiency (PCE) of the PSCs using the Ag grid/CNT hybrid anode is 0.61%, which is 24.5% higher than that of the pure Ag grids with a PCE of 0.49%. Further investigations to improve the performance of the solar cells based on the printed hybrid TCFs are ongoing.
|
|
| 4. |
- Mo, Lixin, et al.
(författare)
-
Silver Nanoparticles Based Ink with Moderate Sintering in Flexible and Printed Electronics
- 2019
-
Ingår i: International Journal of Molecular Sciences. - : MDPI AG. - 1661-6596 .- 1422-0067. ; 20:9
-
Tidskriftsartikel (refereegranskat)abstract
- Printed electronics on flexible substrates has attracted tremendous research interest research thanks its low cost, large area production capability and environmentally friendly advantages. Optimal characteristics of silver nanoparticles (Ag NPs) based inks are crucial for ink rheology, printing, post-print treatment, and performance of the printed electronics devices. In this review, the methods and mechanisms for obtaining Ag NPs based inks that are highly conductive under moderate sintering conditions are summarized. These characteristics are particularly important when printed on temperature sensitive substrates that cannot withstand sintering of high temperature. Strategies to tailor the protective agents capping on the surface of Ag NPs, in order to optimize the sizes and shapes of Ag NPs as well as to modify the substrate surface, are presented. Different (emerging) sintering technologies are also discussed, including photonic sintering, electrical sintering, plasma sintering, microwave sintering, etc. Finally, applications of the Ag NPs based ink in transparent conductive film (TCF), thin film transistor (TFT), biosensor, radio frequency identification (RFID) antenna, stretchable electronics and their perspectives on flexible and printed electronics are presented.
|
|
| 5. |
- Kuo, Ping Heng, et al.
(författare)
-
An integrated edge and Fog system for future communication networks
- 2018
-
Ingår i: 2018 IEEE Wireless Communications and Networking Conference Workshops (WCNCW). ; , s. 338-343
-
Konferensbidrag (refereegranskat)abstract
- Put together, the edge and fog form a large diverse pool of computing and networking resources from different owners that can be leveraged towards low latency applications as well as for alleviating high traffic volume in future networks including 5G and beyond. This paper sets out a framework for the integration of edge and fog computing and networking leveraging on ongoing specifications by ETSI MEC ISG and the OpenFog Consortium. It also presents the technological gaps that need to be addressed before such an integrated solution can be developed. These noticeably include challenges relating to the volatility of resources, heterogeneity of underlying technologies, virtualization of devices, and security issues. The framework presented is a Launchpad for a complete solution under development by the 5G-CORAL consortium.
|
|
| 6. |
- Li, Kaiyuan, et al.
(författare)
-
Inerting and dilution – nitrogen foam suppressions of air mixing effect and flame intensification
- 2024
-
Ingår i: Proceedings of the Combustion Institute. - : Elsevier Ltd. - 1540-7489 .- 1873-2704. ; 40:1-4
-
Tidskriftsartikel (refereegranskat)abstract
- To reveal the flame intensification caused by foam agents extinguishing oil fires, inert gas foam generated by compressed nitrogen was used to extinguish oil pool fires, and the suppression mechanisms of the inert foaming gas on air mixing effect and flame intensification were investigated. The results show that nitrogen replaces the air in the foam, resulting in the inerting effect. At the same time, the released nitrogen dilutes the ambient oxygen concentration, producing the dilution effect. Due to the combined effects of inerting and dilution, the nitrogen foam reduced the extinguishment time by an average of 30.5 % and 32.1 % compared to compressed and aspirated air foams. For flame intensification, this work corrected the positive correlation between the dimensionless heat release rate increase and pool radius proposed by an existing study, and experimentally demonstrated that it is inversely proportional to 1/4 power of the pool radius. The dimensionless analysis shows that the flame intensification of nitrogen foam was reduced by approximately 30 % compared to air foam. Combining with experiments, it was found that the flame intensification of nitrogen foam was reduced by 25 %-36 % compared to air foam under the combined effects of inerting and dilution, of which the inerting and dilution effect accounted for approximately 20 % and 10 %, respectively. This study further corroborated the role of the air mixing effect in flame intensification and also found that the inerting effect remains generally stable with the change of experimental conditions because nitrogen replaces an equal volume of air. Therefore, the differences in the overall suppression effect of nitrogen foam on flame intensification mainly stem from the dilution effect.
|
|
| 7. |
- Li, Yuhong, et al.
(författare)
-
Enhancing the internet of things with knowledge-driven software-defined networking technology : Future perspectives
- 2020
-
Ingår i: Sensors. - : MDPI AG. - 1424-8220. ; 20:12, s. 1-20
-
Tidskriftsartikel (refereegranskat)abstract
- The Internet of Things (IoT) connects smart devices to enable various intelligent services. The deployment of IoT encounters several challenges, such as difficulties in controlling and managing IoT applications and networks, problems in programming existing IoT devices, long service provisioning time, underused resources, as well as complexity, isolation and scalability, among others. One fundamental concern is that current IoT networks lack flexibility and intelligence. A network-wide flexible control and management are missing in IoT networks. In addition, huge numbers of devices and large amounts of data are involved in IoT, but none of them have been tuned for supporting network management and control. In this paper, we argue that Software-defined Networking (SDN) together with the data generated by IoT applications can enhance the control and management of IoT in terms of flexibility and intelligence. We present a review for the evolution of SDN and IoT and analyze the benefits and challenges brought by the integration of SDN and IoT with the help of IoT data. We discuss the perspectives of knowledge-driven SDN for IoT through a new IoT architecture and illustrate how to realize Industry IoT by using the architecture. We also highlight the challenges and future research works toward realizing IoT with the knowledge-driven SDN.
|
|
| 8. |
- Li, Yi, et al.
(författare)
-
Past, present and future of IEC and IEEE high-voltage and high current testing standards
- 2014
-
Rapport (refereegranskat)abstract
- Recently, IEC and IEEE have published a number of revised and new standards for high-voltage and high-current testing. Significant changes and additions have been introduced to these revised and new standards. CIGRE WG D1.35 has developed a guide to give high-voltage test engineers a broader knowledge of how to apply the latest high-voltage and high-current testing standards. The guide presents a brief account of the history of these standards with the aim to allow readers to gain a better appreciation of the technical background followed by sections summarize the major changes made to the standards in their latest revisions to provide a general picture of the revisions. Finally, some discussion is given on the practical implications of these changes. Practical examples are provided to illustrate some of the new techniques and new procedures. The guide also lists areas of possible improvements to the standards for future revisions.
|
|
| 9. |
- Xin, Zhiqing, et al.
(författare)
-
Surface energy guided patterning for printed electronics applications
- 2018
-
Ingår i: 45th International IARIGAI conference.
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- We demonstrated patterning method for silver nanoparticle ink by wire-wound rod coating on commercial paper substrate. The hydrophobic and hydrophilic zones (patterns) on the paper surface were created by combining coating of hydrophobic dispersion with selective plasma treatment using a mask. Thanks to the surface energy difference in different zones, the silver nanoparticle ink self-aligned to form desired patterns, e.g. a matrix of lines of 0.5 mm wide with 0.3 mm spacing.
|
|
