The mechanically guided assembly that relies on the compressive buckling of strate- gically patterned 2D thin films represents a robust route to complex 3D mesostructures in advanced materials and even functional micr...The mechanically guided assembly that relies on the compressive buckling of strate- gically patterned 2D thin films represents a robust route to complex 3D mesostructures in advanced materials and even functional micro-devices. Based on this approach, formation of complex 3D configurations with suspended curvy features or hierarchical geometries remains a challenge. In this paper, we incorporate the prestrained shape memory polymer in the 2D precur- sor design to enable local rolling deformations after the mechanical assembly through compressive buckling. A theoretical model captures quantitatively the effect of key design parameters on local rolling deformations. The combination of precisely controlled global buckling and local rolling expands substantially the range of accessible 3D configurations. The combined experimental and theoretical studies over a dozen of examples demonstrate the utility of the proposed strategy in achieving complex reprogrammable 3D mesostructures.展开更多
This paper proposes a novel method of magnetically guided assembly to construct multi- layer porous scaffold for three-dimensional cell culture by apply magnetic microfibers. Microfibers are composed of biocompatible ...This paper proposes a novel method of magnetically guided assembly to construct multi- layer porous scaffold for three-dimensional cell culture by apply magnetic microfibers. Microfibers are composed of biocompatible and biodegradable alginate solution with homogeneous magnetic nanopar- ticles, which are continuously spun from a microfluidic device by precise pressure control of the syringe pump. Magnetic nanoparticles enable the control of magnetic field on microfibers. Meanwhile, mag- netized device combining with a round permanent magnet are utilized to guide the distribution of spouted microfibers. The device is composed by pure iron wire arrays and wax, which stimulates pow- erful magnetic flux density and magnetic field gradients for the capture and assembly of microfibers. Thus, magnetic microfibers are spun on desired places of the magnetized device by motion control of the micromanipulation robot, and precise locations are adjusted by magnetic force couple with the assist of glass micropipette. Afterwards, microfibers are spatially organized by periodic magnetic force and crossed layer-by-layer to form micro-pore structure with both length and width of 650μm. Finally, the authors construct a multilayer microfiber-based scaffold with high porosity to provide a satisfactory environment for long-term cell culture. The experimental results demonstrate the effectiveness of the proposed method.展开更多
Development of miniaturized three-dimensional(3 D)fliers with integrated functional components has important implications to a diverse range of engineering areas.Among the various active and passive miniaturized 3 D f...Development of miniaturized three-dimensional(3 D)fliers with integrated functional components has important implications to a diverse range of engineering areas.Among the various active and passive miniaturized 3 D fliers reported previously,a class of 3 D electronic fliers inspired by wind-dispersed seeds show promising potentials,owing to the lightweight and noiseless features,aside from the stable rotational fall associated with a low falling velocity.While on-demand shape-morphing capabilities are essential for those 3 D electronic fliers,the realization of such miniaturized systems remains very challenging,due to the lack of fast-response 3 D actuators that can be seamlessly integrated with 3 D electronic fliers.Here we develop a type of morphable3 D mesofliers with shape memory polymer(SMP)-based electrothermal actuators,capable of large degree of actuation deformations,with a fast response(e.g.,~1 s).Integration of functional components,including sensors,controllers,and chip batteries,enables development of intelligent 3 D mesoflier systems that can achieve the on-demand unfolding,triggered by the processing of real-time sensed information(e.g.,acceleration and humidity data).Such intelligent electronic mesofliers are capable of both the low-air-drag rising and the low-velocity falling,and thereby,can be used to measure the humidity fields in a wide 3 D space by simple hand throwing,according to our demonstrations.The developed electronic mesofliers can also be integrated with other types of physical/chemical sensors for uses in different application scenarios.展开更多
RNA-based therapeutics have emerged as a promising approach for the treatment of various diseases,including cancer,genetic disorders,and infectious diseases.However,the delivery of RNA molecules into target cells has ...RNA-based therapeutics have emerged as a promising approach for the treatment of various diseases,including cancer,genetic disorders,and infectious diseases.However,the delivery of RNA molecules into target cells has been a major challenge due to their susceptibility to degradation and inefficient cellular uptake.To overcome these hurdles,DNA-based nano technology offers an unprecedented opportunity as a potential delivery platform for RNA therapeutics.Due to its excellent characteristics such as programmability and biocompatibility,these DNA-based nanostructures,composed of DNA molecules assembled into precise and programmable structures,have garnered significant attention as ideal building materials for protecting and delivering RNA payloads to the desired cellular destinations.In this review,we highlight the current progress in the design and application of three DNA-based nanostructures:DNA origami,lipid-nanoparticle(LNP)technology related to frame guided assembly(FGA),and DNA hydrogel for the delivery of RNA molecules.Their biomedical applications are briefly discussed and the challenges and future perspectives in this field are also highlighted.展开更多
基金X.G. and Z.X. contributed equally to this work. Y.Z. acknowledges the support from the National Natural Science Foundation of China （Grant Nos. 11502129 and 11722217） and the Tsinghua National Laboratory for Information Science and Technology. Y.H. acknowledges the support from the NSF （Grant Nos. CMMI1400169, CMMI1534120 and CMMI1635443）. X.G. acknowledges the support from the National Natural Science Foundation of China （Grant Nos. 11702155）.
文摘The mechanically guided assembly that relies on the compressive buckling of strate- gically patterned 2D thin films represents a robust route to complex 3D mesostructures in advanced materials and even functional micro-devices. Based on this approach, formation of complex 3D configurations with suspended curvy features or hierarchical geometries remains a challenge. In this paper, we incorporate the prestrained shape memory polymer in the 2D precur- sor design to enable local rolling deformations after the mechanical assembly through compressive buckling. A theoretical model captures quantitatively the effect of key design parameters on local rolling deformations. The combination of precisely controlled global buckling and local rolling expands substantially the range of accessible 3D configurations. The combined experimental and theoretical studies over a dozen of examples demonstrate the utility of the proposed strategy in achieving complex reprogrammable 3D mesostructures.
基金supported by the Beijing Natural Science Foundation under Grant No.4164099the National Nature Science Foundation of China under Grant Nos.61375108,61520106011,and 61603044
文摘This paper proposes a novel method of magnetically guided assembly to construct multi- layer porous scaffold for three-dimensional cell culture by apply magnetic microfibers. Microfibers are composed of biocompatible and biodegradable alginate solution with homogeneous magnetic nanopar- ticles, which are continuously spun from a microfluidic device by precise pressure control of the syringe pump. Magnetic nanoparticles enable the control of magnetic field on microfibers. Meanwhile, mag- netized device combining with a round permanent magnet are utilized to guide the distribution of spouted microfibers. The device is composed by pure iron wire arrays and wax, which stimulates pow- erful magnetic flux density and magnetic field gradients for the capture and assembly of microfibers. Thus, magnetic microfibers are spun on desired places of the magnetized device by motion control of the micromanipulation robot, and precise locations are adjusted by magnetic force couple with the assist of glass micropipette. Afterwards, microfibers are spatially organized by periodic magnetic force and crossed layer-by-layer to form micro-pore structure with both length and width of 650μm. Finally, the authors construct a multilayer microfiber-based scaffold with high porosity to provide a satisfactory environment for long-term cell culture. The experimental results demonstrate the effectiveness of the proposed method.
基金support from the National Natural Science Foundation of China(12050004 and 11921002)the Tsinghua National Laboratory for Information Science and Technology,and a grant from the Institute for Guo Qiang,Tsinghua University(2019GQG1012)+3 种基金support from the National Natural Science Foundation of China(11902178)the Natural Science Foundation of Beijing Municipality(3204043)China Postdoctoral Science Foundation(2019M650648)support from the National Natural Science Foundation of China(61904095)。
文摘Development of miniaturized three-dimensional(3 D)fliers with integrated functional components has important implications to a diverse range of engineering areas.Among the various active and passive miniaturized 3 D fliers reported previously,a class of 3 D electronic fliers inspired by wind-dispersed seeds show promising potentials,owing to the lightweight and noiseless features,aside from the stable rotational fall associated with a low falling velocity.While on-demand shape-morphing capabilities are essential for those 3 D electronic fliers,the realization of such miniaturized systems remains very challenging,due to the lack of fast-response 3 D actuators that can be seamlessly integrated with 3 D electronic fliers.Here we develop a type of morphable3 D mesofliers with shape memory polymer(SMP)-based electrothermal actuators,capable of large degree of actuation deformations,with a fast response(e.g.,~1 s).Integration of functional components,including sensors,controllers,and chip batteries,enables development of intelligent 3 D mesoflier systems that can achieve the on-demand unfolding,triggered by the processing of real-time sensed information(e.g.,acceleration and humidity data).Such intelligent electronic mesofliers are capable of both the low-air-drag rising and the low-velocity falling,and thereby,can be used to measure the humidity fields in a wide 3 D space by simple hand throwing,according to our demonstrations.The developed electronic mesofliers can also be integrated with other types of physical/chemical sensors for uses in different application scenarios.
基金National Basic Research Plan of China(2023YFA0915201)Beijing Municipal Science&Technology Commission(Z231100007223003)National Natural Science Foundation of China(21890731,21821001,21890730,and 32270627)。
文摘RNA-based therapeutics have emerged as a promising approach for the treatment of various diseases,including cancer,genetic disorders,and infectious diseases.However,the delivery of RNA molecules into target cells has been a major challenge due to their susceptibility to degradation and inefficient cellular uptake.To overcome these hurdles,DNA-based nano technology offers an unprecedented opportunity as a potential delivery platform for RNA therapeutics.Due to its excellent characteristics such as programmability and biocompatibility,these DNA-based nanostructures,composed of DNA molecules assembled into precise and programmable structures,have garnered significant attention as ideal building materials for protecting and delivering RNA payloads to the desired cellular destinations.In this review,we highlight the current progress in the design and application of three DNA-based nanostructures:DNA origami,lipid-nanoparticle(LNP)technology related to frame guided assembly(FGA),and DNA hydrogel for the delivery of RNA molecules.Their biomedical applications are briefly discussed and the challenges and future perspectives in this field are also highlighted.
