The field of metasurface research has rapidly developed in the past decade.Electron-beam lithography(EBL)is an excellent tool used for rapid prototyping of metasurfaces.However,Gaussian-beam EBL generally struggles wi...The field of metasurface research has rapidly developed in the past decade.Electron-beam lithography(EBL)is an excellent tool used for rapid prototyping of metasurfaces.However,Gaussian-beam EBL generally struggles with low throughput.In conjunction with the recent rise of interest in metasurfaces made of low-index dielectric materials,we propose in this study the use of a relatively unexplored chemically amplified resist,SU-8 with EBL,as a method for rapid prototyping of low-index metasurfaces.We demonstrate the use of SU-8 grating on silicon for cost-efficient fabrication of an all-dielectric multilevel security print for anti-counterfeiting purposes,which encrypt different optical information with different light illumination conditions,namely,bright-field reflection,dark-field reflection,and cross-polarized reflection.The large-scale print(1 mm^(2))could be exposed in a relatively short time(~11 min)due to the ultrahigh sensitivity of the resist,while the feature size of~200 nm was maintained,demonstrating that SU-8 EBL resist serves as a good candidate for rapid prototyping of metasurface designs.Our results could find applications in the general area of increasing EBL patterning speed for a variety of other devices and structures.展开更多
Two-photon polymerisation lithography enables the three-dimensional(3D)-printing of high-resolution micron-and nano-scale structures.Structures that are 3D-printed using proprietary resins are transparent and are suit...Two-photon polymerisation lithography enables the three-dimensional(3D)-printing of high-resolution micron-and nano-scale structures.Structures that are 3D-printed using proprietary resins are transparent and are suitable as optical components.However,achieving a mix of opaque and transparent structures in a single optical component is challenging and requires multiple material systems or the manual introduction of ink after fabrication.In this study,we investigated an overexposure printing process for laser decomposition,which typically produces uncontrollable and random‘burnt’structures.Specifically,we present a printing strategy to control this decomposition process,realising the on-demand printing of opaque or transparent structures in a single lithographic step using a single resin.Using this method,opaque structures can be printed with a minimum feature size of approximately 10μm,which exhibit<15%transmittance at a thickness of approximately 30μm.We applied this process to print an opaque aperture integrated with a transparent lens to demonstrate an improved imaging contrast.展开更多
The advancements in tactile sensor technology have found wide-ranging applications in robotic fields,resulting in remarkable achievements in object manipulation and overall human-machine interactions.However,the wides...The advancements in tactile sensor technology have found wide-ranging applications in robotic fields,resulting in remarkable achievements in object manipulation and overall human-machine interactions.However,the widespread availability of high-resolution tactile skins remains limited,due to the challenges of incorporating large-sized,robust sensing units and increased wiring complexity.One approach to achieve high-resolution and robust tactile skins is to integrate a limited number of sensor units(taxels)into a flexible surface material and leverage signal processing techniques to achieve super-resolution sensing.Here,we present a magnetic skin consisting of multi-direction magnetized flexible films and a contactless Hall sensor array.The key features of the proposed sensor include the specific magnetization arrangement,K-Nearest Neighbors(KNN)clustering algorithm and convolutional neural network(CNN)model for signal processing.Using only an array of 4*4 taxels,our magnetic skin is capable of achieving super-resolution perception over an area of 48400mm^(2),with an average localization error of 1.2 mm.By employing neural network algorithms to decouple the multidimensional signals,the skin can achieve multi-point and multi-scale perception.We also demonstrate the promising potentials of the proposed sensor in intelligent control,by simultaneously controlling two vehicles with trajectory mapping on the magnetic skin.展开更多
基金National Research Foundation Singapore(NRF-CRP20-2017-0004,NRF-NRFI06-2020-0005)。
文摘The field of metasurface research has rapidly developed in the past decade.Electron-beam lithography(EBL)is an excellent tool used for rapid prototyping of metasurfaces.However,Gaussian-beam EBL generally struggles with low throughput.In conjunction with the recent rise of interest in metasurfaces made of low-index dielectric materials,we propose in this study the use of a relatively unexplored chemically amplified resist,SU-8 with EBL,as a method for rapid prototyping of low-index metasurfaces.We demonstrate the use of SU-8 grating on silicon for cost-efficient fabrication of an all-dielectric multilevel security print for anti-counterfeiting purposes,which encrypt different optical information with different light illumination conditions,namely,bright-field reflection,dark-field reflection,and cross-polarized reflection.The large-scale print(1 mm^(2))could be exposed in a relatively short time(~11 min)due to the ultrahigh sensitivity of the resist,while the feature size of~200 nm was maintained,demonstrating that SU-8 EBL resist serves as a good candidate for rapid prototyping of metasurface designs.Our results could find applications in the general area of increasing EBL patterning speed for a variety of other devices and structures.
基金funded by the Singapore University of Technology and Design(SUTD)through the SUTD Ph.D.Fellowship.
文摘Two-photon polymerisation lithography enables the three-dimensional(3D)-printing of high-resolution micron-and nano-scale structures.Structures that are 3D-printed using proprietary resins are transparent and are suitable as optical components.However,achieving a mix of opaque and transparent structures in a single optical component is challenging and requires multiple material systems or the manual introduction of ink after fabrication.In this study,we investigated an overexposure printing process for laser decomposition,which typically produces uncontrollable and random‘burnt’structures.Specifically,we present a printing strategy to control this decomposition process,realising the on-demand printing of opaque or transparent structures in a single lithographic step using a single resin.Using this method,opaque structures can be printed with a minimum feature size of approximately 10μm,which exhibit<15%transmittance at a thickness of approximately 30μm.We applied this process to print an opaque aperture integrated with a transparent lens to demonstrate an improved imaging contrast.
基金supported in part by the National Key R&D Program of China under Grant 2022YFC2401903in part by the National Natural Science Foundation of China under Grant 52205424+1 种基金in part by the“Pioneer”and“Leading Goose”R&D Program of Zhejiang Province under Grant 2023C01170in part by Zhejiang Provincial Natural Science Foundation of China under Grant LY23A020001.
文摘The advancements in tactile sensor technology have found wide-ranging applications in robotic fields,resulting in remarkable achievements in object manipulation and overall human-machine interactions.However,the widespread availability of high-resolution tactile skins remains limited,due to the challenges of incorporating large-sized,robust sensing units and increased wiring complexity.One approach to achieve high-resolution and robust tactile skins is to integrate a limited number of sensor units(taxels)into a flexible surface material and leverage signal processing techniques to achieve super-resolution sensing.Here,we present a magnetic skin consisting of multi-direction magnetized flexible films and a contactless Hall sensor array.The key features of the proposed sensor include the specific magnetization arrangement,K-Nearest Neighbors(KNN)clustering algorithm and convolutional neural network(CNN)model for signal processing.Using only an array of 4*4 taxels,our magnetic skin is capable of achieving super-resolution perception over an area of 48400mm^(2),with an average localization error of 1.2 mm.By employing neural network algorithms to decouple the multidimensional signals,the skin can achieve multi-point and multi-scale perception.We also demonstrate the promising potentials of the proposed sensor in intelligent control,by simultaneously controlling two vehicles with trajectory mapping on the magnetic skin.
