Micro-and nano-fibers of shape memory polymers(SMP)offer multiple advantages like high specific surface area,poros-ity,and intelligence,and are suitable for biomedical applications.In this study,biodegradable poly(p-d...Micro-and nano-fibers of shape memory polymers(SMP)offer multiple advantages like high specific surface area,poros-ity,and intelligence,and are suitable for biomedical applications.In this study,biodegradable poly(p-dioxanone)(PPDO)materials were incorporated to improve the brittleness of shape memory polylactic acid(PLA),and plasticizers were used to reduce the transition temperature of SMP composites such that their transitions could be induced close to body temperature.Furthermore,an electrostatic spinning technology was applied to prepare SMP fibers with wrinkled structures and regulate their microstructures and morphologies such that the intelligent transition of wrinkled and smooth morphologies can be achieved on the fiber surface.The application of this controllable-morphology fiber membrane in intelligent controlled drug release and scar inhibition after Ahmed Glaucoma Valve(AGV)implantation was also studied.The drug release from the stretched and deformed drug-loaded fiber membranes was faster than those from membranes with the original shape.This membrane with micro-and nano-fibers had good anti-scarring effects that improved after drug loading.The achievement of intelligent controlled drug release and the evident anti-scarring effects of the membrane broaden the application of SMP fibers in the biomedical field.展开更多
Controllable formation of microstructures in the assembled graphene film could tune the physical properties and broaden its applications in flexible electronics.Many efforts have been made to control the formation of ...Controllable formation of microstructures in the assembled graphene film could tune the physical properties and broaden its applications in flexible electronics.Many efforts have been made to control the formation of wrinkles and ripples in graphene films.However,the formation of orderly wrinkles in graphene film remains a challenge.Here,we reported a simple strategy for the fabrication of graphene film with periodic and parallel wrinkles with a pre-stretched polydimethylsiloxane substrate.The width of the wrinkles in graphene can be controlled by changing the pre-stretched strain of the substrate.The average width of wrinkles in graphene film on the substrate with pre-stretched strain of 10%,20%,and 50%was about 3.68,2.99 and 2.01µm,respectively.The morphological evolution of wrinkled double-layered graphene under mechanical deformation was observed and studied.Furthermore,a strain sensor was constructed based on the wrinkled graphene,showing high sensitivity,large working range and excellent cyclic stability.These strain sensors show great potential in real-time motion detection,health surveillance and electronic skins.展开更多
In this paper,we report a novel nanoscale wrinkle-structure fabrication process using fluorocarbon plasma on poly(dimethylsiloxane)(PDMS)and Solaris membranes.Wrinkles with wavelengths of hundreds of nanometers were o...In this paper,we report a novel nanoscale wrinkle-structure fabrication process using fluorocarbon plasma on poly(dimethylsiloxane)(PDMS)and Solaris membranes.Wrinkles with wavelengths of hundreds of nanometers were obtained on these two materials,showing that the fabrication process was universally applicable.By varying the plasma-treating time,the wavelength of the wrinkle structure could be controlled.Highly transparent membranes with wrinkle patterns were obtained when the plasmatreating time was o125 s.The transmittances of these membranes were 490%in the visible region,making it difficult to distinguish them from a flat membrane.The deposited fluorocarbon polymer also dramatically reduced the surface energy,which allowed us to replicate the wrinkle pattern with high precision onto other membranes without any surfactant coating.The combined advantages of high electron affinity and high transparency enabled the fabricated membrane to improve the performance of a triboelectric nanogenerator.This nanoscale,single-step,and universal wrinkle-pattern fabrication process,with the functionality of high transparency and ultra-low surface energy,shows an attractive potential for future applications in microand nanodevices,especially in transparent energy harvesters.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.11802075,12072094,81870654,and 82070956)the Fundamental Research Funds for the Central Universities(No.IR2021106 and IR2021232)Applied Technology Research and Development Program of Heilongjiang Provincial Science and Technology Department(GA20C008).
文摘Micro-and nano-fibers of shape memory polymers(SMP)offer multiple advantages like high specific surface area,poros-ity,and intelligence,and are suitable for biomedical applications.In this study,biodegradable poly(p-dioxanone)(PPDO)materials were incorporated to improve the brittleness of shape memory polylactic acid(PLA),and plasticizers were used to reduce the transition temperature of SMP composites such that their transitions could be induced close to body temperature.Furthermore,an electrostatic spinning technology was applied to prepare SMP fibers with wrinkled structures and regulate their microstructures and morphologies such that the intelligent transition of wrinkled and smooth morphologies can be achieved on the fiber surface.The application of this controllable-morphology fiber membrane in intelligent controlled drug release and scar inhibition after Ahmed Glaucoma Valve(AGV)implantation was also studied.The drug release from the stretched and deformed drug-loaded fiber membranes was faster than those from membranes with the original shape.This membrane with micro-and nano-fibers had good anti-scarring effects that improved after drug loading.The achievement of intelligent controlled drug release and the evident anti-scarring effects of the membrane broaden the application of SMP fibers in the biomedical field.
基金This work was financially supported by the National Natural Science Foundation of China(51772335)the Science and Technology Program of Guangzhou(201904010450).
文摘Controllable formation of microstructures in the assembled graphene film could tune the physical properties and broaden its applications in flexible electronics.Many efforts have been made to control the formation of wrinkles and ripples in graphene films.However,the formation of orderly wrinkles in graphene film remains a challenge.Here,we reported a simple strategy for the fabrication of graphene film with periodic and parallel wrinkles with a pre-stretched polydimethylsiloxane substrate.The width of the wrinkles in graphene can be controlled by changing the pre-stretched strain of the substrate.The average width of wrinkles in graphene film on the substrate with pre-stretched strain of 10%,20%,and 50%was about 3.68,2.99 and 2.01µm,respectively.The morphological evolution of wrinkled double-layered graphene under mechanical deformation was observed and studied.Furthermore,a strain sensor was constructed based on the wrinkled graphene,showing high sensitivity,large working range and excellent cyclic stability.These strain sensors show great potential in real-time motion detection,health surveillance and electronic skins.
基金This work is supported by the National Natural Science Foundation of China(Grant No.61674004 and 91323304)National Key R&D Project from Ministry of Science and Technology,China(2016YFA0202701)+1 种基金the Beijing Science&Technology Project(Grant No.D151100003315003)the Beijing Natural Science Foundation of China(Grant No.4141002).
文摘In this paper,we report a novel nanoscale wrinkle-structure fabrication process using fluorocarbon plasma on poly(dimethylsiloxane)(PDMS)and Solaris membranes.Wrinkles with wavelengths of hundreds of nanometers were obtained on these two materials,showing that the fabrication process was universally applicable.By varying the plasma-treating time,the wavelength of the wrinkle structure could be controlled.Highly transparent membranes with wrinkle patterns were obtained when the plasmatreating time was o125 s.The transmittances of these membranes were 490%in the visible region,making it difficult to distinguish them from a flat membrane.The deposited fluorocarbon polymer also dramatically reduced the surface energy,which allowed us to replicate the wrinkle pattern with high precision onto other membranes without any surfactant coating.The combined advantages of high electron affinity and high transparency enabled the fabricated membrane to improve the performance of a triboelectric nanogenerator.This nanoscale,single-step,and universal wrinkle-pattern fabrication process,with the functionality of high transparency and ultra-low surface energy,shows an attractive potential for future applications in microand nanodevices,especially in transparent energy harvesters.
