The intensive development of micro-/nanotechnologies offers a new route to construct sophisticated architectures of emerging soft electronics.Among the many classes of stretchable materials,micro-/nanostructured poly(...The intensive development of micro-/nanotechnologies offers a new route to construct sophisticated architectures of emerging soft electronics.Among the many classes of stretchable materials,micro-/nanostructured poly(dimethylsiloxane)(PDMS)has emerged as a vital building block based on its merits of flexibility,stretchability,simple processing,and,more importantly,high degrees of freedom of incorporation with other functional materials,including metals and semiconductors.The artificially designed geometries play important roles in achieving the desired mechanical and electrical performances of devices and thus show great potential for applications in the fields of stretchable displays,sensors and actuators as well as in health-monitoring device platforms.Meanwhile,novel lithographic methods to produce stretchable platforms with superb reliability have recently attracted research interest.The aim of this review is to comprehensively summarize the progress regarding micro-/nanostructured PDMS and their promising soft electronic applications.This review is concluded with a brief outlook and further research directions.展开更多
Nano-structured photon management is currently an interesting topic since it can enhance the optical absorption and reduce the surface reflection which will improve the performance of many kinds of optoelectronic devi...Nano-structured photon management is currently an interesting topic since it can enhance the optical absorption and reduce the surface reflection which will improve the performance of many kinds of optoelectronic devices, such as Si-based solar cells and light emitting diodes. Here, we report the fabrication of periodically nano-patterned Si structures by using polystyrene nano-sphere lithography technique. By changing the diameter of nano-spheres and the dry etching parameters, such as etching time and etching power, the morphologies of formed Si nano-structures can be well controlled as revealed by atomic force microscopy.A good broadband antireflection property has been achieved for the formed periodically nano-patterned Si structures though they have the low aspect ratio(<0.53). The reflection can be significantly reduced compared with that of flat Si substrate in a wavelength range from 400 nm to 1200 nm. The weighted mean reflection under the AM1.5 solar spectrum irradiation can be as low as 3.92% and the corresponding optical absorption is significantly improved, which indicates that the present Si periodic nano-structures can be used in Si-based thin film solar cells.展开更多
This paper introduces the unpublished copy of a Tangut script Garland Sutra华严经(or Flower Ornament Sutra) volume/juan 41第四十一卷stored at the C.V.Starr East Asian Library at the University of California,Berkeley.I...This paper introduces the unpublished copy of a Tangut script Garland Sutra华严经(or Flower Ornament Sutra) volume/juan 41第四十一卷stored at the C.V.Starr East Asian Library at the University of California,Berkeley.It reinforces the assessment of this manuscript as a modern forgery.Through comparing various physical features of the same volume stored in other countries,and the history of their acquisition,this paper traces the lithographic reproduction of this volume to the early twentieth century and its later circulation.This research also compares the Berkeley copy with the Princeton copy of volume 77 which is the other only known Tangut Garland Sutra in America.The fundamental difference between the two copies prove that the former was a modern forgery but the latter a Yuan period product of movable type wooden block print.展开更多
In recent years,microfluidic systems have evolved to incorporate increasingly complex multi-layer and multi-materialstructures.While conventional 2-dimensional microfluidic systems are typically fabricated with lithog...In recent years,microfluidic systems have evolved to incorporate increasingly complex multi-layer and multi-materialstructures.While conventional 2-dimensional microfluidic systems are typically fabricated with lithographic techniques,the increase in system complexity necessitates a more versatile set of fabrication techniques.Similarly,although 3Dprinting can easily produce intricate microfluidic geometries,integrating multiple membranes and electrodecomponents remains challenging.This study proposes a toolkit for fabricating free-standing 3-dimensionalmicrofluidic systems for biomedical devices,incorporating flow channels,electrodes,and membranes.The fabricationtechniques include molding separation using 3D printed molds,laser-based processing,and component assembly,each achieving micron resolution.Here,we introduce a novel approach to integrate membranes into microfluidics bydirectly curing elastomer-based microfluidics with the membrane through replica molding,while preservingmembrane functionality by effectively removing elastomer residues through reactive ion etching.The resultingmembrane-elastomer microfluidic component significantly simplifies the assembly of intricate microfluidic systems,reducing the device size to millimeter dimensions,suitable for implantable applications.The toolkit’s versatility isdemonstrated by a redox flow iontophoretic drug delivery prototype at the millimeter scale,featuring two electrodes,four membranes,and four microfluidic channels.展开更多
Exceptional points(EPs)have been extensively explored in mechanical,acoustic,plasmonic,and photonic systems.However,little is known about the role of EPs in tailoring the dynamic tunability of optical devices.A specif...Exceptional points(EPs)have been extensively explored in mechanical,acoustic,plasmonic,and photonic systems.However,little is known about the role of EPs in tailoring the dynamic tunability of optical devices.A specific type of EPs known as chiral EPs has recently attracted much attention for controlling the flow of light and for building sensors with better responsivity.A recently demonstrated route to chiral EPs via lithographically defined symmetric Mie scatterers on the rim of resonators has not only provided the much-needed mechanical stability for studying chiral EPs,but also helped reduce losses originating from nanofabrication imperfections,facilitating the in-situ study of chiral EPs and their contribution to the dynamics and tunability of resonators.Here,we use asymmetric Mie scatterers to break the rotational symmetry of a microresonator,to demonstrate deterministic thermal tuning across a chiral EP,and to demonstrate EP-mediated chiral optical nonlinear response and efficient electro-optic tuning.Our results indicate asymmetric electro-optic modulation with up to 17 dB contrast at GHz and CMOS-compatible voltage levels.Such wafer-scale nano-manufacturing of chiral electro-optic modulators and the chiral EP-tailored tunning may facilitate new micro-resonator functionalities in quantum information processing,electromagnetic wave control,and optical interconnects.展开更多
Metal oxide cluster(MOC)photoresists are highly promising materials for the next generation of extreme ultraviolet lithography(EUVL).The consecutive exploration of novel MOC materials and their structural irradiation ...Metal oxide cluster(MOC)photoresists are highly promising materials for the next generation of extreme ultraviolet lithography(EUVL).The consecutive exploration of novel MOC materials and their structural irradiation chemistry are the major concerns associated with EUVL.Herein,we report two bicoordinated tin-oxo clusters(TOCs),the organic ligands of which contain both adamantane carboxylic acids and alkyl groups(methyl:Sn_(4)–Me–C10;butyl:Sn_(4)–Bu–C10).We explore the correlation between the structures of the TOCs and their patterning properties by adjusting the alkyl groups coordinated to the Sn atom.The structural variation causes different irradiation chemistry,with Sn_(4)–Me–C10 exhibiting improved resolution and Sn_(4)–Bu–C10 demonstrating higher sensitivity.These differences are attributed to the bonding energies of the Sn-methyl and Sn-butyl groups,the size of the resulting alkyl radicals,and their reaction probabilities.Both clusters occur in the reactions of Sn–C bond cleavage and the decarboxylation of adamantane carboxylic acids upon irradiation.However,the entire process exhibits distinct characteristics.Based on the electron-beam lithography and other experiments,we proposed irradiationinduced reaction mechanisms for both clusters.The Sn_(4)–Bu–C10 cluster predominantly undergoes alkane chain linkage,whereas the Sn_(4)–Me–C10 cluster mainly follows the adamantanes linkage pathway.展开更多
Patterning of L10 FePt nanoparticles(NPs) with high coercivity offers a promising route to develop bit-patterned media(BPM) for the next generation magnetic data recording system, but the synthesis of monodisperse FeP...Patterning of L10 FePt nanoparticles(NPs) with high coercivity offers a promising route to develop bit-patterned media(BPM) for the next generation magnetic data recording system, but the synthesis of monodisperse FePt NPs and mass production of their nanopatterns has been a longstanding challenge. Here, highly efficient nanoimprint lithography was applied for large-scale universal patterning, which was achieved by imprinting the solution of a single-source bimetallic precursor. The rigid coplanar metallic cores and the surrounding flexible tails in the bimetallic complex permit the spontaneous molecular arrangements to form the highly ordered negative morphology replicated from the soft template.In-situ pyrolysis study was then investigated by one-pot pyrolysis of the precursor under an Ar/H2 atmosphere, and the resultant NPs were fully characterized to identify the phase,morphology and magnetic properties. Finally, highly-ordered patterns on certain substrates were preserved perfectly after pyrolysis and could be potentially utilized in magnetic data recording media.展开更多
基金supported by the National Research Foundation (NRF) of Korea funded by the Ministry of Science and ICT and Future Planning (MSIP) (2016R1E1A1A01943131)
文摘The intensive development of micro-/nanotechnologies offers a new route to construct sophisticated architectures of emerging soft electronics.Among the many classes of stretchable materials,micro-/nanostructured poly(dimethylsiloxane)(PDMS)has emerged as a vital building block based on its merits of flexibility,stretchability,simple processing,and,more importantly,high degrees of freedom of incorporation with other functional materials,including metals and semiconductors.The artificially designed geometries play important roles in achieving the desired mechanical and electrical performances of devices and thus show great potential for applications in the fields of stretchable displays,sensors and actuators as well as in health-monitoring device platforms.Meanwhile,novel lithographic methods to produce stretchable platforms with superb reliability have recently attracted research interest.The aim of this review is to comprehensively summarize the progress regarding micro-/nanostructured PDMS and their promising soft electronic applications.This review is concluded with a brief outlook and further research directions.
基金supported by NSFC(Nos.61036001and 11274155)"973"pro ject(2013CB632101)NSF of Jiangsu Province(BK2010010)and PAPD
文摘Nano-structured photon management is currently an interesting topic since it can enhance the optical absorption and reduce the surface reflection which will improve the performance of many kinds of optoelectronic devices, such as Si-based solar cells and light emitting diodes. Here, we report the fabrication of periodically nano-patterned Si structures by using polystyrene nano-sphere lithography technique. By changing the diameter of nano-spheres and the dry etching parameters, such as etching time and etching power, the morphologies of formed Si nano-structures can be well controlled as revealed by atomic force microscopy.A good broadband antireflection property has been achieved for the formed periodically nano-patterned Si structures though they have the low aspect ratio(<0.53). The reflection can be significantly reduced compared with that of flat Si substrate in a wavelength range from 400 nm to 1200 nm. The weighted mean reflection under the AM1.5 solar spectrum irradiation can be as low as 3.92% and the corresponding optical absorption is significantly improved, which indicates that the present Si periodic nano-structures can be used in Si-based thin film solar cells.
文摘This paper introduces the unpublished copy of a Tangut script Garland Sutra华严经(or Flower Ornament Sutra) volume/juan 41第四十一卷stored at the C.V.Starr East Asian Library at the University of California,Berkeley.It reinforces the assessment of this manuscript as a modern forgery.Through comparing various physical features of the same volume stored in other countries,and the history of their acquisition,this paper traces the lithographic reproduction of this volume to the early twentieth century and its later circulation.This research also compares the Berkeley copy with the Princeton copy of volume 77 which is the other only known Tangut Garland Sutra in America.The fundamental difference between the two copies prove that the former was a modern forgery but the latter a Yuan period product of movable type wooden block print.
文摘In recent years,microfluidic systems have evolved to incorporate increasingly complex multi-layer and multi-materialstructures.While conventional 2-dimensional microfluidic systems are typically fabricated with lithographic techniques,the increase in system complexity necessitates a more versatile set of fabrication techniques.Similarly,although 3Dprinting can easily produce intricate microfluidic geometries,integrating multiple membranes and electrodecomponents remains challenging.This study proposes a toolkit for fabricating free-standing 3-dimensionalmicrofluidic systems for biomedical devices,incorporating flow channels,electrodes,and membranes.The fabricationtechniques include molding separation using 3D printed molds,laser-based processing,and component assembly,each achieving micron resolution.Here,we introduce a novel approach to integrate membranes into microfluidics bydirectly curing elastomer-based microfluidics with the membrane through replica molding,while preservingmembrane functionality by effectively removing elastomer residues through reactive ion etching.The resultingmembrane-elastomer microfluidic component significantly simplifies the assembly of intricate microfluidic systems,reducing the device size to millimeter dimensions,suitable for implantable applications.The toolkit’s versatility isdemonstrated by a redox flow iontophoretic drug delivery prototype at the millimeter scale,featuring two electrodes,four membranes,and four microfluidic channels.
基金supported by the Defense Advanced Research Projects Agency(N660012114034)H.L.acknowledges the scholarship provided by the Republic of Korea Navy(ROK Nawy)+1 种基金The design and fabrication of the micro-heater and chiral MRR are supported by AFOSR(FA9550-18-1-0300)S.K.O.acknowledges the Air Force Offce of Scientific Research(AFOSR)Multi-University Research Initiative(FA9550-21-1-0202)and AFOSR(FA9550-18-1-0235)。
文摘Exceptional points(EPs)have been extensively explored in mechanical,acoustic,plasmonic,and photonic systems.However,little is known about the role of EPs in tailoring the dynamic tunability of optical devices.A specific type of EPs known as chiral EPs has recently attracted much attention for controlling the flow of light and for building sensors with better responsivity.A recently demonstrated route to chiral EPs via lithographically defined symmetric Mie scatterers on the rim of resonators has not only provided the much-needed mechanical stability for studying chiral EPs,but also helped reduce losses originating from nanofabrication imperfections,facilitating the in-situ study of chiral EPs and their contribution to the dynamics and tunability of resonators.Here,we use asymmetric Mie scatterers to break the rotational symmetry of a microresonator,to demonstrate deterministic thermal tuning across a chiral EP,and to demonstrate EP-mediated chiral optical nonlinear response and efficient electro-optic tuning.Our results indicate asymmetric electro-optic modulation with up to 17 dB contrast at GHz and CMOS-compatible voltage levels.Such wafer-scale nano-manufacturing of chiral electro-optic modulators and the chiral EP-tailored tunning may facilitate new micro-resonator functionalities in quantum information processing,electromagnetic wave control,and optical interconnects.
基金supported by the National Natural Science Foundation of China(grant nos.22090011 and 22378052)the Fundamental Research Funds for China Central Universities(grant nos.DUT22LAB608 and DUT20RC(3)030)Key R&D Program of Shandong Province(grant no.2021CXGC010308).
文摘Metal oxide cluster(MOC)photoresists are highly promising materials for the next generation of extreme ultraviolet lithography(EUVL).The consecutive exploration of novel MOC materials and their structural irradiation chemistry are the major concerns associated with EUVL.Herein,we report two bicoordinated tin-oxo clusters(TOCs),the organic ligands of which contain both adamantane carboxylic acids and alkyl groups(methyl:Sn_(4)–Me–C10;butyl:Sn_(4)–Bu–C10).We explore the correlation between the structures of the TOCs and their patterning properties by adjusting the alkyl groups coordinated to the Sn atom.The structural variation causes different irradiation chemistry,with Sn_(4)–Me–C10 exhibiting improved resolution and Sn_(4)–Bu–C10 demonstrating higher sensitivity.These differences are attributed to the bonding energies of the Sn-methyl and Sn-butyl groups,the size of the resulting alkyl radicals,and their reaction probabilities.Both clusters occur in the reactions of Sn–C bond cleavage and the decarboxylation of adamantane carboxylic acids upon irradiation.However,the entire process exhibits distinct characteristics.Based on the electron-beam lithography and other experiments,we proposed irradiationinduced reaction mechanisms for both clusters.The Sn_(4)–Bu–C10 cluster predominantly undergoes alkane chain linkage,whereas the Sn_(4)–Me–C10 cluster mainly follows the adamantanes linkage pathway.
基金supported by the National Natural Science Foundation of China (21701112, 21504074 and 51573151)Hong Kong Research Grants Council (HKBU12317216, Poly U153062/18P and Poly U153015/14P)+2 种基金Areas of Excellence Scheme, University Grants Committee of HKSAR (Ao E/P-03/08)the Hong Kong Polytechnic University (1-ZE1C and 1-ZE25)the Science, Technology and Innovation Committee of Shenzhen Municipality (JCYJ20160531193836532)
文摘Patterning of L10 FePt nanoparticles(NPs) with high coercivity offers a promising route to develop bit-patterned media(BPM) for the next generation magnetic data recording system, but the synthesis of monodisperse FePt NPs and mass production of their nanopatterns has been a longstanding challenge. Here, highly efficient nanoimprint lithography was applied for large-scale universal patterning, which was achieved by imprinting the solution of a single-source bimetallic precursor. The rigid coplanar metallic cores and the surrounding flexible tails in the bimetallic complex permit the spontaneous molecular arrangements to form the highly ordered negative morphology replicated from the soft template.In-situ pyrolysis study was then investigated by one-pot pyrolysis of the precursor under an Ar/H2 atmosphere, and the resultant NPs were fully characterized to identify the phase,morphology and magnetic properties. Finally, highly-ordered patterns on certain substrates were preserved perfectly after pyrolysis and could be potentially utilized in magnetic data recording media.
