Air-permeable and ultrathin conductive electrodes are essential for next-generation soft electronics,including breathable wearables,on-skin devices and biointegrated electronics.However,conventional metallization stra...Air-permeable and ultrathin conductive electrodes are essential for next-generation soft electronics,including breathable wearables,on-skin devices and biointegrated electronics.However,conventional metallization strategies,such as sputtering and ink-printing,often suffer from severe vertical charge leakage due to the porous and ultrathin characteristics of nanofibrous networks,leading to device short-circuiting,operational failure and limited vertical integration.Here,we present a solvent-selective dissolutionassisted transfer printing strategy to achieve surface-confined metallization of ultrathin,lightweight,and gas-permeable nanofibrous networks,enabling lateral conductivity while maintaining vertical insulation.This transfer printing process facilitates not only the rapid formation of conductive patterns on the surface of nanofibrous networks but also mechanical reinforcement through solvent evaporation-induced interlocked fiber-fiber welding.Meanwhile,the strategy preserves the high permeability of the nanofibrous networks and imparts a unique combination of surface conductivity(2Ωcm)and vertical insulativity(10^(11)Ωcm).The resulting anisotropic conductive networks enable low-voltage wearable heaters,high-sensitive pressure sensors,and ultralight temperature sensors.A pressure-temperature dual-modal sensing patch is further fabricated for intelligent grasping classification.The proposed surface-confined metallization strategy enables rapid fabrication of an anisotropic conductive network as a building block to construct air-permeable,ultrathin and lightweight wearable electronics.展开更多
Transfer printing based on switchable adhesive is essential for developing unconventional systems,including flexible electronics,stretchable electronics,and micro light-emitting diode(LED)displays.Here we report a des...Transfer printing based on switchable adhesive is essential for developing unconventional systems,including flexible electronics,stretchable electronics,and micro light-emitting diode(LED)displays.Here we report a design of switchable dry adhesive based on shape memory polymer(SMP)with hemispherical indenters,which offers a continuously tunable and reversible adhesion through the combination of the preloading effect and the thermal actuation of SMP.Experimental and numerical studies reveal the fundamental aspects of design,fabrication,and operation of the switchable dry adhesive.Demonstrations of this adhesive concept in transfer printing of flat objects(e.g.,silicon wafers),three-dimensional(3D)objects(e.g.,stainless steel balls),and rough objects(e.g.,frosted glasses)in two-dimensional(2D)or 3D layouts illustrate its unusual manipulation capabilities in heterogeneous material integration applications.展开更多
The novel reactive transfer printing of silk was carried out through a hot-press adhesion and steaming. The special transfer paper was prepared by coating the paste mainly containing hot-melt adhesive hlgh-substituted...The novel reactive transfer printing of silk was carried out through a hot-press adhesion and steaming. The special transfer paper was prepared by coating the paste mainly containing hot-melt adhesive hlgh-substituted hydroxypropyl cellulose （H-HPC） and printing thickener earboxymethyl cellulose （CMC）. The effects of each ingredient in the paste on color yield of the prints and dye penetration were investigated. The major results indicate that, color yield is chiefly governed by the adhesion extent imparted by H-HPC, the type of fixing alkaline agent, and the content of urea. Trichloroacetic acid （TCAA） as the fixing alkaline agent and adding 5% urea can enhance the color depth obviously. Dye penetration depends on the coating quantity on the transfer paper, the contents of urea and dicyandiamide. The printed silk possesses a higher color yield, color fastness of grade 3 or above, clear sharpness, and good handle when the paste contains 3 % H-HPC, 0. 7 % CMC, 3 % TCAA, 5 % urea, 3 % dicyandiamide, and 0. 5 % physical sorbent nano-silica.展开更多
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
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
Reusable electronics have received widespread attention and are urgently needed. Here, nanocellulosebased liquid metal(NC-LM) printed circuit has been fabricated by the evaporation-induced transfer printing technology...Reusable electronics have received widespread attention and are urgently needed. Here, nanocellulosebased liquid metal(NC-LM) printed circuit has been fabricated by the evaporation-induced transfer printing technology. In this way, the liquid metal pattern is embedded into the nanocellulose membrane, which is beneficial for the stability of the circuit during use. Besides, the NC-LM circuit is ultrathin with just tens of microns. In particular, the finished product is environmentally friendly because it can be completely dissolved by water, and both the liquid metal ink and the nanocellulose membrane can be easily recollected and reused, thereby reducing waste and pollution to the environment. Several examples of flexible circuits have been designed to evaluate their performance. The mechanism of evaporation-induced transfer printing technology involves the deposition, aggregation, and coverage tightly of the nanosized cellulose fibrils as the water evaporated. This study provides an economical and environmentally friendly way for the fabrication of renewable flexible electronics.展开更多
There is an urgent need for novel processes that can integrate different functional nanostructures onto specific substrates,so as to meet the fast-growing need for broad applications in nanoelectronics,nanophotonics,a...There is an urgent need for novel processes that can integrate different functional nanostructures onto specific substrates,so as to meet the fast-growing need for broad applications in nanoelectronics,nanophotonics,and fexible optoelectronics.Existing direct-lithography methods are difficult to use on fexible,nonplanar,and biocompatible surfaces.Therefore,this fabrication is usually accomplished by nanotransfer printing.However,large-scale integration of multiscale nanostructures with unconventional substrates remains challenging because fabrication yields and quality are often limited by the resolution,uniformity,adhesivity,and integrity of the nanostructures formed by direct transfer.Here,we proposed a resist-based transfer strategy enabled by near-zero adhesion,which was achieved by molecular modification to attain a critical surface energy interval.This approach enabled the intact transfer of wafer-scale,ultrathin-resist nanofilms onto arbitrary substrates with mitigated cracking and wrinkling,thereby facilitating the in situ fabrication of nanostructures for functional devices.Applying this approach,fabrication of three-dimensional-stacked multilayer structures with enhanced functionalities,nanoplasmonic structures with~10 nm resolution,and MoS2-based devices with excellent performance was demonstrated on specific substrates.These results collectively demonstrated the high stability,reliability,and throughput of our strategy for optical and electronic device applications.展开更多
The molecular transfer printing（MTP） technique has been invented to fabricate chemical patterns with high fidelity using homopolymer inks. In this work, we systematically studied the effects of the molecular weights...The molecular transfer printing（MTP） technique has been invented to fabricate chemical patterns with high fidelity using homopolymer inks. In this work, we systematically studied the effects of the molecular weights of homopolymer inks and transfer conditions on the MTP process. We explored a large range of molecular weights（~3.5-56 kg·mol^（-1）） of hydroxyl-terminated polystyrene（PS-OH） and hydroxyl-terminated poly（methyl methacrylate）（PMMA-OH） in the MTP process, and found that the resulting chemical patterns on replicas from all five blends were functional and able to direct the assembly of films of the same blends. The transfer temperature and the film annealing sequences had an impact on the MTP process. MTP was sensitive to the transfer temperature and could only be performed within a certain temperature range, i.e. higher than the glass transition temperature（T_g） of copolymers and lower than the rearrangement temperature of the assembled domains. Pre-organization of the blend films was also necessary for MTP since the preferential wetting of PMMA domains at the replica surface might result in the formation of a PMMA wetting layer to prevent the presentation of underlying chemical patterns to the replica surface.展开更多
Stretchable and flexible electronics represent emerging and exciting directions for future electronics,while transfer printing plays an essential and mainstream role in integrating electronics onto application substra...Stretchable and flexible electronics represent emerging and exciting directions for future electronics,while transfer printing plays an essential and mainstream role in integrating electronics onto application substrates.However,existing transfer printing approaches have restrictions for electronics in terms of stiffness and dimensionality,as well as limitations for substrates in terms of surface and adhesion.Here,we report a versatile soap bubble transfer printing technique that,through a volume modulation strategy,enables the adhesion-independent,damage-free,and lowcontamination integration of rigid,flexible,and three-dimensional curved electronics onto substrates with complex surfaces and challenging adhesion.To demonstrate the versatility and compatibility of the soap bubble transfer printing technique,we performed not only special behaviors such as wraplike,multilayer,selective,and interior printing,but also integrated flexible electronics onto various human organ models,which holds promise for health monitoring in both noninvasive and invasive manners.展开更多
Silicon photonics(SiPh)technology has become a key platform for developing photonic integrated circuits due to its CMOS compatibility and scalable manufacturing.However,integrating efficient on-chip optical sources an...Silicon photonics(SiPh)technology has become a key platform for developing photonic integrated circuits due to its CMOS compatibility and scalable manufacturing.However,integrating efficient on-chip optical sources and in-line amplifiers remains challenging due to silicon’s indirect bandgap.In this study,we developed prefabricated standardized InAs/GaAs quantum-dot(QD)active devices optimized for micro-transfer printing and successfully integrated them on SiPh integrated circuits.By transfer-printing standardized QD devices onto specific regions of the SiPh chip,we realized O-band semiconductor optical amplifiers(SOAs),distributed feedback(DFB)lasers,and widely tunable lasers(TLs).The SOAs reached an on-chip gain of 7.5 dB at 1299 nm and maintained stable performance across a wide input power range.The integrated DFB lasers achieved waveguide(WG)-coupled output powers of up to 19.7 mW,with a side-mode suppression ratio(SMSR)of 33.3 dB,and demonstrated notable robustness against optical feedback,supporting error-free data rates of 30 Gbps without additional isolators.Meanwhile,the TLs demonstrated a wavelength tuning range exceeding 35 nm,and a WG-coupled output power greater than 3 m W.The micro-transfer printing approach effectively decouples the fabrication of non-native devices from the SiPh process,allowing back-end integration of the Ⅲ–Ⅴ devices.Our approach offers a viable path toward fully integrated Ⅲ–Ⅴ/ SiPh platforms capable of supporting high-speed,high-capacity communication.展开更多
Transfer printing is a powerful and versatile integration method that is attracting increasing attention as regards both scientific research and industrial manufacturing.The transfer printing technique utilizes the vi...Transfer printing is a powerful and versatile integration method that is attracting increasing attention as regards both scientific research and industrial manufacturing.The transfer printing technique utilizes the viscoelastic properties of a stamp to pick devices(ink)from a donor substrate and print them onto a target substrate,exploiting the competition between several interfacial adhesion forces.The overall yield can be improved through the introduction of external stimuli such as light,heat,solution,pressure,and magnetic fields during the transfer printing operation.This review summarizes different transfer printing methods based on their working principles and discusses their detailed applications in photonic integrated circuits,taking lasers,semiconductor optical amplifiers,photodetectors,and other optical electronic elements as examples.Hence,the feasibility and viability of transfer printing are illustrated.Additionally,future challenges and opportunities for innovative development are discussed.展开更多
Gesture recording,modeling,and understanding based on a robust electronic glove(E-glove)are of great significance for efficient human-machine cooperation in harsh environments.However,such robust edge-intelligence int...Gesture recording,modeling,and understanding based on a robust electronic glove(E-glove)are of great significance for efficient human-machine cooperation in harsh environments.However,such robust edge-intelligence interfaces remain challenging as existing E-gloves are limited in terms of integration,waterproofness,scalability,and interface stability between different components.Here,we report on the design,manufacturing,and application scenarios for a waterproof E-glove,which is of low cost,lightweight,and scalable for mass production,as well as environmental robustness,waterproofness,and washability.An improved neural network architecture is proposed to implement environment-adaptive learning and inference for hand gestures,which achieves an amphibious recognition accuracy of 100%in 26 categories by analyzing 2,600 hand gesture patterns.We demonstrate that the E-glove can be used for amphibious remote vehicle navigation via hand gestures,potentially opening the way for efficient human-human and human-machine cooperation in harsh environments.展开更多
As an emerging processing technology,transfer printing enables the assembly of functional material arrays(called inks)on various substrates with micro/nanoscale resolution and has been widely used in the fabrication o...As an emerging processing technology,transfer printing enables the assembly of functional material arrays(called inks)on various substrates with micro/nanoscale resolution and has been widely used in the fabrication of flexible electronics and display systems.The critical steps in transfer printing are the ink pick-up and printing processes governed by the switching of adhesion states at the stamp/ink interface.In this review,we first introduce the history of transfer printing in terms of the transfer methods,transferred materials,and applications.Then,the fundamental characteristics of the transfer printing system and typical strategies for regulating the stamp/ink interfacial adhesion strength are summarized and exemplified.Finally,future challenges and opportunities for developing the novel stamps,inks,and substrates with intelligent adhesion capability are discussed,aiming to inspire the innovation in the design of transfer printing systems.展开更多
Inorganic-based micro light-emitting diodes (microLEDs) offer more fascinating properties and unique demands in next-generation displays. However, the small size of the microLED chip (1–100 µm) makes it extremel...Inorganic-based micro light-emitting diodes (microLEDs) offer more fascinating properties and unique demands in next-generation displays. However, the small size of the microLED chip (1–100 µm) makes it extremely challenging for high efficiency and low cost to accurately, selectively, integrate millions of microLED chips. Recent impressive technological advances have overcome the drawbacks of traditional pick-and-place techniques when they were utilized in the assembly of microLED display, including the most broadly recognized laser lift-off technique, contact micro-transfer printing (µTP) technique, laser non-contact µTP technique, and self-assembly technique. Herein, we firstly review the key developments in mass transfer technique and highlight their potential value, covering both the state-of-the-art devices and requirements for mass transfer in the assembly of the ultra-large-area display and virtual reality glasses. We begin with the significant challenges and the brief history of mass transfer technique, and expand that mass transfer technique is composed of two major techniques, namely, the epitaxial Lift-off technique and the pick-and-place technique. The basic concept and transfer effects for each representative epitaxial Lift-off and pick-and-place technique in mass transfer are then overviewed separately. Finally, the potential challenges and future research directions of mass transfer are discussed.展开更多
Health monitoring of structures and people requires the integration of sensors and devices on various 3D curvilinear,hierarchically structured,and even dynamically changing surfaces.Therefore,it is highly desirable to...Health monitoring of structures and people requires the integration of sensors and devices on various 3D curvilinear,hierarchically structured,and even dynamically changing surfaces.Therefore,it is highly desirable to explore conformal manufacturing techniques to fabricate and integrate soft deformable devices on complex 3D curvilinear surfaces.Although planar fabrication methods are not directly suitable to manufacture conformal devices on 3D curvilinear surfaces,they can be combined with stretchable structures and the use of transfer printing or assembly methods to enable the device integration on 3D surfaces.Combined with functional nanomaterials,various direct printing and writing methods have also been developed to fabricate conformal electronics on curved surfaces with intimate contact even over a large area.After a brief summary of the recent advancement of the recent conformal manufacturing techniques,we also discuss the challenges and potential opportunities for future development in this burgeoning field of conformal electronics on complex 3D surfaces.展开更多
Micro-LEDs(μLEDs)have advantages in terms of brightness,power consumption,and response speed.In addition,they can also be used as micro-sensors implanted in the body via flexible electronic skin.One of the key techni...Micro-LEDs(μLEDs)have advantages in terms of brightness,power consumption,and response speed.In addition,they can also be used as micro-sensors implanted in the body via flexible electronic skin.One of the key techniques involved in the fabrication ofμLED-based devices is transfer printing.Although numerous methods have been proposed for transfer printing,improving the yield ofμLED arrays is still a formidable task.In this paper,we propose a novel method for improving the yield ofμLED arrays transferred by the stamping method,using an innovative design of piezoelectrically driven asymmetric micro-gripper.Traditional grippers are too large to manipulateμLEDs,and therefore two micro-sized cantilevers are added at the gripper tips.AμLED manipulation system is constructed based on the micro-gripper together with a three-dimensional positioning system.Experimental results using this system show that it can be used successfully to manipulateμLED arrays.展开更多
Flexible electronics utilizing single crystalline semiconductors typically require post-growth processes to assemble and incorporate the crystalline materials onto flexible substrates. Here we present a high-precision...Flexible electronics utilizing single crystalline semiconductors typically require post-growth processes to assemble and incorporate the crystalline materials onto flexible substrates. Here we present a high-precision transfer-printing method for vertical arrays of single crystalline semiconductor materials with widely varying aspect ratios and densities enabling the assembly of arrays on flexible substrates in a vertical fashion. Complementary fabrication processes for integrating transferred arrays into flexible devices are also presented and characterized. Robust contacts to transferred silicon wire arrays are demonstrated and shown to be stable under flexing stress down to bending radii of 20 mm. The fabricated devices exhibit a reversible tactile response enabling silicon based, nonpiezoelectric, and flexible tactile sensors. The presented system leads the way towards high-throughput, manufacturable, and scalable fabrication of flexible devices.展开更多
MXene-based films have been intensively explored for construction of piezoresistive flexible pressure sensors owing to their excellent mechanical and electrical properties.High pressure sensitivity relies on pre-moldi...MXene-based films have been intensively explored for construction of piezoresistive flexible pressure sensors owing to their excellent mechanical and electrical properties.High pressure sensitivity relies on pre-molding a flexible substrate,or regulating the micromorphology of MXene sheets,to obtain a micro-structured surface.However,the two avenues usually require complicated and time-consuming microfabrication or wet chemical processing,and are limited to non-adjustable topographicelectrical(topo-electro)properties.Herein,we propose a lithographic printing inspired in-situ transfer(LIPIT)strategy to fabricate MXene-ink films(MIFs).In LIPIT,MIFs not only inherit ridge-and-valley microstructure from paper substrate,but also achieve localized topo-electro tunability by programming ink-writing patterns and cycles.The MIF-based flexible pressure sensor with periodical topo-electro gradient exhibits remarkably boosted sensitivity in a wide sensing range(low detection limit of 0.29 Pa and working range of 100 kPa).The MIF sensor demonstrates versatile applicability in both subtle and vigorous pressuresensing fields,ranging from pulse wave extraction and machine learning-assisted surface texture recognition to piano-training glove(PT-glove)for piano learning.The LIPIT is quick,low-cost,and compatible with free ink/substrate combinations,which promises a versatile toolbox for designing functional MXene films with tailored morphological-mechanical-electrical properties for extended application scenarios.展开更多
Semitransparent organic photodetectors(ST-OPDs)are promising for applications in smart windows and electronic displays due to their inherent transparency.However,their transmittance is often limited by the low transmi...Semitransparent organic photodetectors(ST-OPDs)are promising for applications in smart windows and electronic displays due to their inherent transparency.However,their transmittance is often limited by the low transmittance of conventional electrodes.In this work,we developed a cost-effective and facile transfer printing process for fabricating PEDOT:PSS top electrodes,which were subsequently used to construct ST-OPDs.The resulting PEDOT:PSS electrodes exhibit excellent optical transmittance,exceeding 90%across the ultraviolet-visible-near infrared spectrum.Consequently,the ST-OPDs based on these electrodes achieve an impressive average visible transmittance(AVT)of 74.8%and a specific detectivity of exceeding 5×10^(11)Jones.Moreover,the high transparency of the PEDOT:PSS electrodes enables dual-sided responsiveness,allowing for heart rate monitoring from both sides in photoplethysmography tests,a feature that facilitates seamless integration with readout circuits.Additionally,the transfer-printing method exhibits broad applicability across various active layers.These findings highlight the potential of our transfer printing approach for fabricating high-performance ST-OPDs,paving the way for integratable,biocompatible,and invisible optical-sensing applications in transparent electronics and beyond.展开更多
The development of responsive metamaterials has enabled the realization of compact tunable photonic devices capable of manipulating the amplitude,polarization,wave vector and frequency of light.Integration of semicond...The development of responsive metamaterials has enabled the realization of compact tunable photonic devices capable of manipulating the amplitude,polarization,wave vector and frequency of light.Integration of semiconductors into the active regions of metallic resonators is a proven approach for creating nonlinear metamaterials through optoelectronic control of the semiconductor carrier density.Metal-free subwavelength resonant semiconductor structures offer an alternative approach to create dynamic metamaterials.We present InAs plasmonic disk arrays as a viable resonant metamaterial at terahertz frequencies.Importantly,InAs plasmonic disks exhibit a strong nonlinear response arising from electric field-induced intervalley scattering,resulting in a reduced carrier mobility thereby damping the plasmonic response.We demonstrate nonlinear perfect absorbers configured as either optical limiters or saturable absorbers,including flexible nonlinear absorbers achieved by transferring the disks to polyimide films.Nonlinear plasmonic metamaterials show potential for use in ultrafast terahertz(THz)optics and for passive protection of sensitive electromagnetic devices.展开更多
基金supported by the National Natural Science Foundation of China(22434007,22104021,52303075,22404102)the Taishan Young Scholar Program of Shandong Province(tsqnz20231235)+2 种基金the Natural Science Foundation of Shandong Province(ZR2024QB338,ZR2023QB227)the Higher Education Institutions Youth Innovation Team Plan of Shandong Province(2024KJH046)the Shandong Postdoctora1 Science Foundation(SDCX-ZG-202400279)。
文摘Air-permeable and ultrathin conductive electrodes are essential for next-generation soft electronics,including breathable wearables,on-skin devices and biointegrated electronics.However,conventional metallization strategies,such as sputtering and ink-printing,often suffer from severe vertical charge leakage due to the porous and ultrathin characteristics of nanofibrous networks,leading to device short-circuiting,operational failure and limited vertical integration.Here,we present a solvent-selective dissolutionassisted transfer printing strategy to achieve surface-confined metallization of ultrathin,lightweight,and gas-permeable nanofibrous networks,enabling lateral conductivity while maintaining vertical insulation.This transfer printing process facilitates not only the rapid formation of conductive patterns on the surface of nanofibrous networks but also mechanical reinforcement through solvent evaporation-induced interlocked fiber-fiber welding.Meanwhile,the strategy preserves the high permeability of the nanofibrous networks and imparts a unique combination of surface conductivity(2Ωcm)and vertical insulativity(10^(11)Ωcm).The resulting anisotropic conductive networks enable low-voltage wearable heaters,high-sensitive pressure sensors,and ultralight temperature sensors.A pressure-temperature dual-modal sensing patch is further fabricated for intelligent grasping classification.The proposed surface-confined metallization strategy enables rapid fabrication of an anisotropic conductive network as a building block to construct air-permeable,ultrathin and lightweight wearable electronics.
基金The authors acknowledge the supports of the National Natural Science Foundation of China(Grant Nos.11872331 and U20A6001)Zhejiang University K.P.Chao’s High Technology Development Foundation.
文摘Transfer printing based on switchable adhesive is essential for developing unconventional systems,including flexible electronics,stretchable electronics,and micro light-emitting diode(LED)displays.Here we report a design of switchable dry adhesive based on shape memory polymer(SMP)with hemispherical indenters,which offers a continuously tunable and reversible adhesion through the combination of the preloading effect and the thermal actuation of SMP.Experimental and numerical studies reveal the fundamental aspects of design,fabrication,and operation of the switchable dry adhesive.Demonstrations of this adhesive concept in transfer printing of flat objects(e.g.,silicon wafers),three-dimensional(3D)objects(e.g.,stainless steel balls),and rough objects(e.g.,frosted glasses)in two-dimensional(2D)or 3D layouts illustrate its unusual manipulation capabilities in heterogeneous material integration applications.
基金Jiangsu Province Project of Postgraduate Innovation Engineering,China(No.CXZZ12_0821)Industry-academic Joint Technological Innovations Fund Project of Jiangsu Province,China(No.BY2012120)Suzhou Project of Scientific and Technical Supporting,China(No.ZXS2012001)
文摘The novel reactive transfer printing of silk was carried out through a hot-press adhesion and steaming. The special transfer paper was prepared by coating the paste mainly containing hot-melt adhesive hlgh-substituted hydroxypropyl cellulose （H-HPC） and printing thickener earboxymethyl cellulose （CMC）. The effects of each ingredient in the paste on color yield of the prints and dye penetration were investigated. The major results indicate that, color yield is chiefly governed by the adhesion extent imparted by H-HPC, the type of fixing alkaline agent, and the content of urea. Trichloroacetic acid （TCAA） as the fixing alkaline agent and adding 5% urea can enhance the color depth obviously. Dye penetration depends on the coating quantity on the transfer paper, the contents of urea and dicyandiamide. The printed silk possesses a higher color yield, color fastness of grade 3 or above, clear sharpness, and good handle when the paste contains 3 % H-HPC, 0. 7 % CMC, 3 % TCAA, 5 % urea, 3 % dicyandiamide, and 0. 5 % physical sorbent nano-silica.
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.
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financially supported by the National Natural Science Foundation of China(No.51605472)the Beijing Municipal Science&Technology Commission research fund(No.Z171100000417004)。
文摘Reusable electronics have received widespread attention and are urgently needed. Here, nanocellulosebased liquid metal(NC-LM) printed circuit has been fabricated by the evaporation-induced transfer printing technology. In this way, the liquid metal pattern is embedded into the nanocellulose membrane, which is beneficial for the stability of the circuit during use. Besides, the NC-LM circuit is ultrathin with just tens of microns. In particular, the finished product is environmentally friendly because it can be completely dissolved by water, and both the liquid metal ink and the nanocellulose membrane can be easily recollected and reused, thereby reducing waste and pollution to the environment. Several examples of flexible circuits have been designed to evaluate their performance. The mechanism of evaporation-induced transfer printing technology involves the deposition, aggregation, and coverage tightly of the nanosized cellulose fibrils as the water evaporated. This study provides an economical and environmentally friendly way for the fabrication of renewable flexible electronics.
基金supported by the National Key Research and Development Program of China(No.2022YFB4602600)the National Natural Science Foundation of China(No.52221001)Hunan Provincial Innovation Foundation for Postgraduate(No.CX20220406)。
文摘There is an urgent need for novel processes that can integrate different functional nanostructures onto specific substrates,so as to meet the fast-growing need for broad applications in nanoelectronics,nanophotonics,and fexible optoelectronics.Existing direct-lithography methods are difficult to use on fexible,nonplanar,and biocompatible surfaces.Therefore,this fabrication is usually accomplished by nanotransfer printing.However,large-scale integration of multiscale nanostructures with unconventional substrates remains challenging because fabrication yields and quality are often limited by the resolution,uniformity,adhesivity,and integrity of the nanostructures formed by direct transfer.Here,we proposed a resist-based transfer strategy enabled by near-zero adhesion,which was achieved by molecular modification to attain a critical surface energy interval.This approach enabled the intact transfer of wafer-scale,ultrathin-resist nanofilms onto arbitrary substrates with mitigated cracking and wrinkling,thereby facilitating the in situ fabrication of nanostructures for functional devices.Applying this approach,fabrication of three-dimensional-stacked multilayer structures with enhanced functionalities,nanoplasmonic structures with~10 nm resolution,and MoS2-based devices with excellent performance was demonstrated on specific substrates.These results collectively demonstrated the high stability,reliability,and throughput of our strategy for optical and electronic device applications.
基金finically supported by the National Natural Science Foundation of China(Nos.51773201 and 51373166)“The Hundred Talents Program”from the Chinese Academy of Sciences,and Department of Science and Technology of Jilin Province(Nos.20150204027GX and 20160414032GH)
文摘The molecular transfer printing（MTP） technique has been invented to fabricate chemical patterns with high fidelity using homopolymer inks. In this work, we systematically studied the effects of the molecular weights of homopolymer inks and transfer conditions on the MTP process. We explored a large range of molecular weights（~3.5-56 kg·mol^（-1）） of hydroxyl-terminated polystyrene（PS-OH） and hydroxyl-terminated poly（methyl methacrylate）（PMMA-OH） in the MTP process, and found that the resulting chemical patterns on replicas from all five blends were functional and able to direct the assembly of films of the same blends. The transfer temperature and the film annealing sequences had an impact on the MTP process. MTP was sensitive to the transfer temperature and could only be performed within a certain temperature range, i.e. higher than the glass transition temperature（T_g） of copolymers and lower than the rearrangement temperature of the assembled domains. Pre-organization of the blend films was also necessary for MTP since the preferential wetting of PMMA domains at the replica surface might result in the formation of a PMMA wetting layer to prevent the presentation of underlying chemical patterns to the replica surface.
基金supported by the National Natural Science Foundation of China(12272079,12172189,11921002)fundamental research funds for the central universities(DUT21YG213)。
文摘Stretchable and flexible electronics represent emerging and exciting directions for future electronics,while transfer printing plays an essential and mainstream role in integrating electronics onto application substrates.However,existing transfer printing approaches have restrictions for electronics in terms of stiffness and dimensionality,as well as limitations for substrates in terms of surface and adhesion.Here,we report a versatile soap bubble transfer printing technique that,through a volume modulation strategy,enables the adhesion-independent,damage-free,and lowcontamination integration of rigid,flexible,and three-dimensional curved electronics onto substrates with complex surfaces and challenging adhesion.To demonstrate the versatility and compatibility of the soap bubble transfer printing technique,we performed not only special behaviors such as wraplike,multilayer,selective,and interior printing,but also integrated flexible electronics onto various human organ models,which holds promise for health monitoring in both noninvasive and invasive manners.
基金European Union(CALADAN)(825453)Dutch Growth Fund PhotonDelta project。
文摘Silicon photonics(SiPh)technology has become a key platform for developing photonic integrated circuits due to its CMOS compatibility and scalable manufacturing.However,integrating efficient on-chip optical sources and in-line amplifiers remains challenging due to silicon’s indirect bandgap.In this study,we developed prefabricated standardized InAs/GaAs quantum-dot(QD)active devices optimized for micro-transfer printing and successfully integrated them on SiPh integrated circuits.By transfer-printing standardized QD devices onto specific regions of the SiPh chip,we realized O-band semiconductor optical amplifiers(SOAs),distributed feedback(DFB)lasers,and widely tunable lasers(TLs).The SOAs reached an on-chip gain of 7.5 dB at 1299 nm and maintained stable performance across a wide input power range.The integrated DFB lasers achieved waveguide(WG)-coupled output powers of up to 19.7 mW,with a side-mode suppression ratio(SMSR)of 33.3 dB,and demonstrated notable robustness against optical feedback,supporting error-free data rates of 30 Gbps without additional isolators.Meanwhile,the TLs demonstrated a wavelength tuning range exceeding 35 nm,and a WG-coupled output power greater than 3 m W.The micro-transfer printing approach effectively decouples the fabrication of non-native devices from the SiPh process,allowing back-end integration of the Ⅲ–Ⅴ devices.Our approach offers a viable path toward fully integrated Ⅲ–Ⅴ/ SiPh platforms capable of supporting high-speed,high-capacity communication.
基金supported by the National Key R&D Program of China[2022YFB2804501]Outstanding Scientific and Technological Talents Project of Jilin Province[20230508097RC]+3 种基金the National Natural Science Foundation of China[62090051,62090052,62090054,62121005,61934003,62227819]the Science and Technology Development Project of Jilin Province[20240302004GX]the Major Science and Technology Special Project of Jilin Province and Changchun City[20210301016GX]Dawn Talent Training Program of CIOMP.
文摘Transfer printing is a powerful and versatile integration method that is attracting increasing attention as regards both scientific research and industrial manufacturing.The transfer printing technique utilizes the viscoelastic properties of a stamp to pick devices(ink)from a donor substrate and print them onto a target substrate,exploiting the competition between several interfacial adhesion forces.The overall yield can be improved through the introduction of external stimuli such as light,heat,solution,pressure,and magnetic fields during the transfer printing operation.This review summarizes different transfer printing methods based on their working principles and discusses their detailed applications in photonic integrated circuits,taking lasers,semiconductor optical amplifiers,photodetectors,and other optical electronic elements as examples.Hence,the feasibility and viability of transfer printing are illustrated.Additionally,future challenges and opportunities for innovative development are discussed.
基金supported by the National Natural Science Foundation of China(Nos.62075040 and 51603227)the National Key R&D Program of China(No.2017YFE0112000)Postgraduate Research&Practice Innovation Program of Jiangsu Province(No.KYCX22_0230).
文摘Gesture recording,modeling,and understanding based on a robust electronic glove(E-glove)are of great significance for efficient human-machine cooperation in harsh environments.However,such robust edge-intelligence interfaces remain challenging as existing E-gloves are limited in terms of integration,waterproofness,scalability,and interface stability between different components.Here,we report on the design,manufacturing,and application scenarios for a waterproof E-glove,which is of low cost,lightweight,and scalable for mass production,as well as environmental robustness,waterproofness,and washability.An improved neural network architecture is proposed to implement environment-adaptive learning and inference for hand gestures,which achieves an amphibious recognition accuracy of 100%in 26 categories by analyzing 2,600 hand gesture patterns.We demonstrate that the E-glove can be used for amphibious remote vehicle navigation via hand gestures,potentially opening the way for efficient human-human and human-machine cooperation in harsh environments.
基金National Natural Science Foundation of China,Grant/Award Number:22035008International Partnership Program of Chinese Academy of Sciences,Grant/Award Number:1A1111KYSB20200010。
文摘As an emerging processing technology,transfer printing enables the assembly of functional material arrays(called inks)on various substrates with micro/nanoscale resolution and has been widely used in the fabrication of flexible electronics and display systems.The critical steps in transfer printing are the ink pick-up and printing processes governed by the switching of adhesion states at the stamp/ink interface.In this review,we first introduce the history of transfer printing in terms of the transfer methods,transferred materials,and applications.Then,the fundamental characteristics of the transfer printing system and typical strategies for regulating the stamp/ink interfacial adhesion strength are summarized and exemplified.Finally,future challenges and opportunities for developing the novel stamps,inks,and substrates with intelligent adhesion capability are discussed,aiming to inspire the innovation in the design of transfer printing systems.
文摘Inorganic-based micro light-emitting diodes (microLEDs) offer more fascinating properties and unique demands in next-generation displays. However, the small size of the microLED chip (1–100 µm) makes it extremely challenging for high efficiency and low cost to accurately, selectively, integrate millions of microLED chips. Recent impressive technological advances have overcome the drawbacks of traditional pick-and-place techniques when they were utilized in the assembly of microLED display, including the most broadly recognized laser lift-off technique, contact micro-transfer printing (µTP) technique, laser non-contact µTP technique, and self-assembly technique. Herein, we firstly review the key developments in mass transfer technique and highlight their potential value, covering both the state-of-the-art devices and requirements for mass transfer in the assembly of the ultra-large-area display and virtual reality glasses. We begin with the significant challenges and the brief history of mass transfer technique, and expand that mass transfer technique is composed of two major techniques, namely, the epitaxial Lift-off technique and the pick-and-place technique. The basic concept and transfer effects for each representative epitaxial Lift-off and pick-and-place technique in mass transfer are then overviewed separately. Finally, the potential challenges and future research directions of mass transfer are discussed.
基金This research is supported by the National Science Foundation(Grant No.ECCS-1933072)the Doctoral New Investigator grant from the American Chemical Society Petro-leum Research Fund(59021-DNI7)the National Heart,Lung,And Blood Institute of the National Institutes of Health under Award Number R61HL154215,and Penn State University.
文摘Health monitoring of structures and people requires the integration of sensors and devices on various 3D curvilinear,hierarchically structured,and even dynamically changing surfaces.Therefore,it is highly desirable to explore conformal manufacturing techniques to fabricate and integrate soft deformable devices on complex 3D curvilinear surfaces.Although planar fabrication methods are not directly suitable to manufacture conformal devices on 3D curvilinear surfaces,they can be combined with stretchable structures and the use of transfer printing or assembly methods to enable the device integration on 3D surfaces.Combined with functional nanomaterials,various direct printing and writing methods have also been developed to fabricate conformal electronics on curved surfaces with intimate contact even over a large area.After a brief summary of the recent advancement of the recent conformal manufacturing techniques,we also discuss the challenges and potential opportunities for future development in this burgeoning field of conformal electronics on complex 3D surfaces.
基金support from the Scientific Research Program of the Tianjin Education Commission(No.2019ZD08).
文摘Micro-LEDs(μLEDs)have advantages in terms of brightness,power consumption,and response speed.In addition,they can also be used as micro-sensors implanted in the body via flexible electronic skin.One of the key techniques involved in the fabrication ofμLED-based devices is transfer printing.Although numerous methods have been proposed for transfer printing,improving the yield ofμLED arrays is still a formidable task.In this paper,we propose a novel method for improving the yield ofμLED arrays transferred by the stamping method,using an innovative design of piezoelectrically driven asymmetric micro-gripper.Traditional grippers are too large to manipulateμLEDs,and therefore two micro-sized cantilevers are added at the gripper tips.AμLED manipulation system is constructed based on the micro-gripper together with a three-dimensional positioning system.Experimental results using this system show that it can be used successfully to manipulateμLED arrays.
文摘Flexible electronics utilizing single crystalline semiconductors typically require post-growth processes to assemble and incorporate the crystalline materials onto flexible substrates. Here we present a high-precision transfer-printing method for vertical arrays of single crystalline semiconductor materials with widely varying aspect ratios and densities enabling the assembly of arrays on flexible substrates in a vertical fashion. Complementary fabrication processes for integrating transferred arrays into flexible devices are also presented and characterized. Robust contacts to transferred silicon wire arrays are demonstrated and shown to be stable under flexing stress down to bending radii of 20 mm. The fabricated devices exhibit a reversible tactile response enabling silicon based, nonpiezoelectric, and flexible tactile sensors. The presented system leads the way towards high-throughput, manufacturable, and scalable fabrication of flexible devices.
基金supported by the National Natural Science Foundation of China(Nos.62122080,62261136551,and 52203365)the Natural Science Foundation of Shanghai(Nos.22ZR1481700 and 22dz1205000)the Shanghai Pujiang Program(No.21PJ1414800).
文摘MXene-based films have been intensively explored for construction of piezoresistive flexible pressure sensors owing to their excellent mechanical and electrical properties.High pressure sensitivity relies on pre-molding a flexible substrate,or regulating the micromorphology of MXene sheets,to obtain a micro-structured surface.However,the two avenues usually require complicated and time-consuming microfabrication or wet chemical processing,and are limited to non-adjustable topographicelectrical(topo-electro)properties.Herein,we propose a lithographic printing inspired in-situ transfer(LIPIT)strategy to fabricate MXene-ink films(MIFs).In LIPIT,MIFs not only inherit ridge-and-valley microstructure from paper substrate,but also achieve localized topo-electro tunability by programming ink-writing patterns and cycles.The MIF-based flexible pressure sensor with periodical topo-electro gradient exhibits remarkably boosted sensitivity in a wide sensing range(low detection limit of 0.29 Pa and working range of 100 kPa).The MIF sensor demonstrates versatile applicability in both subtle and vigorous pressuresensing fields,ranging from pulse wave extraction and machine learning-assisted surface texture recognition to piano-training glove(PT-glove)for piano learning.The LIPIT is quick,low-cost,and compatible with free ink/substrate combinations,which promises a versatile toolbox for designing functional MXene films with tailored morphological-mechanical-electrical properties for extended application scenarios.
基金supported by the National Natural Science Foundation of China(22275029 and 52403254)the Science and Technology Development Plan of Jilin Province(20220204097YY)+1 种基金the funding from Jilin Province(20220502002GH)the 111 Project(B25030).
文摘Semitransparent organic photodetectors(ST-OPDs)are promising for applications in smart windows and electronic displays due to their inherent transparency.However,their transmittance is often limited by the low transmittance of conventional electrodes.In this work,we developed a cost-effective and facile transfer printing process for fabricating PEDOT:PSS top electrodes,which were subsequently used to construct ST-OPDs.The resulting PEDOT:PSS electrodes exhibit excellent optical transmittance,exceeding 90%across the ultraviolet-visible-near infrared spectrum.Consequently,the ST-OPDs based on these electrodes achieve an impressive average visible transmittance(AVT)of 74.8%and a specific detectivity of exceeding 5×10^(11)Jones.Moreover,the high transparency of the PEDOT:PSS electrodes enables dual-sided responsiveness,allowing for heart rate monitoring from both sides in photoplethysmography tests,a feature that facilitates seamless integration with readout circuits.Additionally,the transfer-printing method exhibits broad applicability across various active layers.These findings highlight the potential of our transfer printing approach for fabricating high-performance ST-OPDs,paving the way for integratable,biocompatible,and invisible optical-sensing applications in transparent electronics and beyond.
基金supported in part by the National Science Foundation under contract ECCS 1309835the Air Force Office of Scientific Research under contract FA9550-09-1-0708+1 种基金support from DOEBasic Energy Sciences under Grant No.DE-FG02-09ER46643,under which the THz measurements were performedsupported by a Multidisciplinary University Research Initiative from the Air Force Office of Scientific Research(AFOSR MURI Award No.FA9550-12-1-0488)。
文摘The development of responsive metamaterials has enabled the realization of compact tunable photonic devices capable of manipulating the amplitude,polarization,wave vector and frequency of light.Integration of semiconductors into the active regions of metallic resonators is a proven approach for creating nonlinear metamaterials through optoelectronic control of the semiconductor carrier density.Metal-free subwavelength resonant semiconductor structures offer an alternative approach to create dynamic metamaterials.We present InAs plasmonic disk arrays as a viable resonant metamaterial at terahertz frequencies.Importantly,InAs plasmonic disks exhibit a strong nonlinear response arising from electric field-induced intervalley scattering,resulting in a reduced carrier mobility thereby damping the plasmonic response.We demonstrate nonlinear perfect absorbers configured as either optical limiters or saturable absorbers,including flexible nonlinear absorbers achieved by transferring the disks to polyimide films.Nonlinear plasmonic metamaterials show potential for use in ultrafast terahertz(THz)optics and for passive protection of sensitive electromagnetic devices.
