Transfer printing based on switchable adhesive that heterogeneously integrates materials is essential to develop novel electronic systems,such as flexible electronics and micro LED displays.Here,we report a robust des...Transfer printing based on switchable adhesive that heterogeneously integrates materials is essential to develop novel electronic systems,such as flexible electronics and micro LED displays.Here,we report a robust design of a thermal actuated switchable dry adhesive,which features a stiff sphere embedded in a thermally responsive shape memory polymer(SMP)substrate and encapsulated by an elastomeric membrane.This construct bypasses the unfavorable micro-and nano-fabrication processes and yields an adhesion switchability of over1000 by combining the peel-rate dependent effect of the elastomeric membrane and the thermal actuation of the sub-surface embedded stiff sphere.Experimental and numerical studies reveal the underlying thermal actuated mechanism and provide insights into the design and operation of the switchable adhesive.Demonstrations of this concept in stamps for transfer printing of fragile objects,such as silicon wafers,silicon chips,and inorganic micro-LED chips,onto challenging non-adhesive surfaces illustrate its potential in heterogeneous material integration applications,such as flexible electronics manufacturing and deterministic assembly.展开更多
In this paper, we proposed 10 Gb/s transmission using 4-channel polymer waveguides on the optical electronic printed circuit board. It was simulated by the ray tracing method for tolerance study of optical interconnec...In this paper, we proposed 10 Gb/s transmission using 4-channel polymer waveguides on the optical electronic printed circuit board. It was simulated by the ray tracing method for tolerance study of optical interconnection and fabrication. In order for easy fabrication and high position accuracy, the polymer waveguides were forming silver coated 45° reflective mirrors by dicing method and e-beam deposition for 90° light beam turning. The coupling loss was demonstrated in different polishing grit sizes. The optical interconnection in board-embed 4-channel flexible waveguides was demonstrated with a low propagation loss of 0.1 dB/cm and a clear eye diagram at 2.5 Gb/s data rate per channel.展开更多
The burgeoning interest in flexible electronics necessitates the creation of patterning technology specifically tailored for flexible substrates and complex surface morphologies.Among a variety of patterning technique...The burgeoning interest in flexible electronics necessitates the creation of patterning technology specifically tailored for flexible substrates and complex surface morphologies.Among a variety of patterning techniques,transfer printing emerges as one of the most efficient,cost-effective,and scalable methods.It boasts the ability for high-throughput fabrication of 0–3D micro-and nano-structures on flexible substrates,working in tandem with traditional lithography methods.This review highlights the critical issue of transfer printing:the flawless transfer of devices during the pick-up and printing process.We encapsulate recent advancements in numerous transfer printing techniques,with a particular emphasis on strategies to control adhesion forces at the substrate/device/stamp interfaces.These strategies are employed to meet the requirements of competing fractures for successful pick-up and print processes.The mechanism,advantages,disadvantages,and typical applications of each transfer printing technique will be thoroughly discussed.The conclusion section provides design guidelines and probes potential directions for future advancements.展开更多
In this work, a simple methodology was developed to enhance the patterning resolution of inkjet printing, involving process optimization as well as substrate modification and treatment. The line width of the inkjetpri...In this work, a simple methodology was developed to enhance the patterning resolution of inkjet printing, involving process optimization as well as substrate modification and treatment. The line width of the inkjetprinted silver lines was successfully reduced to 1/3 of the original value using this methodology. Large-area flexible circuits with delicate patterns and good morphology were thus fabricated. The resultant flexible circuits showed excellent electrical conductivity as low as 4.5 Ω/□ and strong tolerance to mechanical bending. The simple methodology is also applicable to substrates with various wettability, which suggests a general strategy to enhance the printing quality of inkjet printing for manufacturing high-performance large-area flexible electronics.展开更多
Flexible electrode films play critical and fundamental roles in the successful development of flexible electronic devices. In this study, carbon nanotubes（CNTs） were implanted into silver（Ag） ink to enhance the el...Flexible electrode films play critical and fundamental roles in the successful development of flexible electronic devices. In this study, carbon nanotubes（CNTs） were implanted into silver（Ag） ink to enhance the electrical conductivity and the reliability of the printed Ag electrode films. The fabricated carbon nanotubes-enriched silver（Ag-CNTs） electrode films were printed on the polyimide substrates by a facile screen printing method and sintered at a relatively low temperature. The resistivity of Ag-CNTs films was decreased by 62.27% compared with the pure Ag film. Additionally, the Ag-CNTs films exhibited excellent flexibility under a bending radius of 4 mm（strain ε = 2.09%） over 1000 cycles. Furthermore, the Ag-CNTs film displayed unchangeable electrical conductivity together with a strong adhesion after an accelerated aging test with 500 thermal shock cycles. These improvements were attributed to the AgCNTs interconnected network structure, which can provide electronic transmission channels and prevent cracks from initiating and propagating.展开更多
基金financial support from the National Natural Science Foundation of China(Grant Nos.11872331 and U20A6001)the Zhejiang University K P Chao’s High Technology Development Foundation。
文摘Transfer printing based on switchable adhesive that heterogeneously integrates materials is essential to develop novel electronic systems,such as flexible electronics and micro LED displays.Here,we report a robust design of a thermal actuated switchable dry adhesive,which features a stiff sphere embedded in a thermally responsive shape memory polymer(SMP)substrate and encapsulated by an elastomeric membrane.This construct bypasses the unfavorable micro-and nano-fabrication processes and yields an adhesion switchability of over1000 by combining the peel-rate dependent effect of the elastomeric membrane and the thermal actuation of the sub-surface embedded stiff sphere.Experimental and numerical studies reveal the underlying thermal actuated mechanism and provide insights into the design and operation of the switchable adhesive.Demonstrations of this concept in stamps for transfer printing of fragile objects,such as silicon wafers,silicon chips,and inorganic micro-LED chips,onto challenging non-adhesive surfaces illustrate its potential in heterogeneous material integration applications,such as flexible electronics manufacturing and deterministic assembly.
文摘In this paper, we proposed 10 Gb/s transmission using 4-channel polymer waveguides on the optical electronic printed circuit board. It was simulated by the ray tracing method for tolerance study of optical interconnection and fabrication. In order for easy fabrication and high position accuracy, the polymer waveguides were forming silver coated 45° reflective mirrors by dicing method and e-beam deposition for 90° light beam turning. The coupling loss was demonstrated in different polishing grit sizes. The optical interconnection in board-embed 4-channel flexible waveguides was demonstrated with a low propagation loss of 0.1 dB/cm and a clear eye diagram at 2.5 Gb/s data rate per channel.
基金financial support from the RGC Senior Research Fellowship Scheme(SRFS2122-5S04)General Research Fund(15304322)+1 种基金RGC Postdoctoral Fellowship(PDFS2324-5S10)State Key Laboratory for Ultraprecision Machining Technology(1-BBXR).
文摘The burgeoning interest in flexible electronics necessitates the creation of patterning technology specifically tailored for flexible substrates and complex surface morphologies.Among a variety of patterning techniques,transfer printing emerges as one of the most efficient,cost-effective,and scalable methods.It boasts the ability for high-throughput fabrication of 0–3D micro-and nano-structures on flexible substrates,working in tandem with traditional lithography methods.This review highlights the critical issue of transfer printing:the flawless transfer of devices during the pick-up and printing process.We encapsulate recent advancements in numerous transfer printing techniques,with a particular emphasis on strategies to control adhesion forces at the substrate/device/stamp interfaces.These strategies are employed to meet the requirements of competing fractures for successful pick-up and print processes.The mechanism,advantages,disadvantages,and typical applications of each transfer printing technique will be thoroughly discussed.The conclusion section provides design guidelines and probes potential directions for future advancements.
基金supported by the National Key Basic Research Program of China(Nos.2014CB648300,2017YFB0404501)the National Natural Science Foundation of China(Nos.21422402,21674050)+8 种基金the Natural Science Foundation of Jiangsu Province(Nos.BK20140060,BK20130037,BK20140865,BM2012010)the Program for Jiangsu Specially-Appointed Professors(No.RK030STP15001)the Program for New Century Excellent Talents in University(No.NCET-13-0872)the NUPT"1311 Project"and Scientific Foundation(Nos.NY213119,NY213169)the Synergetic Innovation Center for Organic Electronics and Information Displays,the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)the Leading Talent of Technological Innovation of National Ten Thousands Talents Program of Chinathe Excellent Scientific and Technological Innovative Teams of Jiangsu Higher Education Institutions(No.TJ217038)the Program for Graduate Students Research and Innovation of Jiangsu Province(No.KYZZ16-0253)the 333 Project of Jiangsu Province(Nos.BRA2017402,BRA2015374)
文摘In this work, a simple methodology was developed to enhance the patterning resolution of inkjet printing, involving process optimization as well as substrate modification and treatment. The line width of the inkjetprinted silver lines was successfully reduced to 1/3 of the original value using this methodology. Large-area flexible circuits with delicate patterns and good morphology were thus fabricated. The resultant flexible circuits showed excellent electrical conductivity as low as 4.5 Ω/□ and strong tolerance to mechanical bending. The simple methodology is also applicable to substrates with various wettability, which suggests a general strategy to enhance the printing quality of inkjet printing for manufacturing high-performance large-area flexible electronics.
基金supported financially by the Joint Funds of the National Natural Science Foundation of China (Grant No. U1601213)the National Natural Science Foundation of China (Grant No. 51601005)the Fundamental Research Funds for the Central Universities.
文摘Flexible electrode films play critical and fundamental roles in the successful development of flexible electronic devices. In this study, carbon nanotubes（CNTs） were implanted into silver（Ag） ink to enhance the electrical conductivity and the reliability of the printed Ag electrode films. The fabricated carbon nanotubes-enriched silver（Ag-CNTs） electrode films were printed on the polyimide substrates by a facile screen printing method and sintered at a relatively low temperature. The resistivity of Ag-CNTs films was decreased by 62.27% compared with the pure Ag film. Additionally, the Ag-CNTs films exhibited excellent flexibility under a bending radius of 4 mm（strain ε = 2.09%） over 1000 cycles. Furthermore, the Ag-CNTs film displayed unchangeable electrical conductivity together with a strong adhesion after an accelerated aging test with 500 thermal shock cycles. These improvements were attributed to the AgCNTs interconnected network structure, which can provide electronic transmission channels and prevent cracks from initiating and propagating.
