The fluidic oscillator is an instrument that can continuously generate a spatially sweeping jet entirely based on its internal geometry without any moving parts.However,the traditional fluidic oscillator has an inhere...The fluidic oscillator is an instrument that can continuously generate a spatially sweeping jet entirely based on its internal geometry without any moving parts.However,the traditional fluidic oscillator has an inherent limitation,that is,the spreading angle cannot be controlled independently,rather by the jet volume flow rate and internal geometry.Accordingly,two types of fluidic oscillators based on the master-slave design are developed in current study to decouple this correlation.In both designs,the master layer inherits the similar oscillation mechanisms of a sweeping jet,and the slave layer resembles a steady jet channel.The difference between the two designs is that Design A has a short diverging exit in the slave layer,but Design B adds a long interaction chamber in the exit channel to intensify flow instability.The external flow fields and governing oscillation properties of these two designs are experimentally explored with time-resolved Particle Image Velocimetry(PIV),while the internal flow dynamics and driving oscillation mechanisms are numerically investigated.By fixing the total volume flow rate,the jet spreading angle of Design A can be increased smoothly from 0°to above 100°by increasing the proportion of master layer’s flow rate from 0 to 100%.For Design B,the control authority of the master layer is significantly enhanced by adding the interaction chamber in the slave layer.In addition,the added chamber causes notable jet oscillation even when the master layer has none input.展开更多
Ionic fluidic devices are gaining interest due to their role in enabling self-powered neuromorphic computing systems.In this study,we present an approach that integrates an iontronic fluidic memristive(IFM)device with...Ionic fluidic devices are gaining interest due to their role in enabling self-powered neuromorphic computing systems.In this study,we present an approach that integrates an iontronic fluidic memristive(IFM)device with low input impedance and a triboelectric nanogenerator(TENG)based on ferrofluid(FF),which has high input impedance.By incorporating contact separation electromagnetic(EMG)signals with low input impedance into our FF TENG device,we enhance the FF TENG’s performance by increasing energy harvesting,thereby enabling the autonomous powering of IFM devices for self-powered computing.Further,replicating neuronal activities using artificial iontronic fluidic systems is key to advancing neuromorphic computing.These fluidic devices,composed of soft-matter materials,dynamically adjust their conductance by altering the solution interface.We developed voltage-controlled memristor and memcapacitor memory in polydimethylsiloxane(PDMS)structures,utilising a fluidic interface of FF and polyacrylic acid partial sodium salt(PAA Na^(+)).The confined ion interactions in this system induce hysteresis in ion transport across various frequencies,resulting in significant ion memory effects.Our IFM successfully replicates diverse electric pulse patterns,making it highly suitable for neuromorphic computing.Furthermore,our system demonstrates synapse-like learning functions,storing and retrieving short-term(STM)and long-term memory(LTM).The fluidic memristor exhibits dynamic synapse-like features,making it a promising candidate for the hardware implementation of neural networks.FF TENG/EMG device adaptability and seamless integration with biological systems enable the development of advanced neuromorphic devices using iontronic fluidic materials,further enhanced by intricate chemical designs for self-powered electronics.展开更多
We report the direct fabrication of a microfluidic chip composed of two high-aspect ratio microfluidic channels with lengths of 3.5 cm and 8 mm in a glass substrate by femtosecond laser micromachining. The fabrication...We report the direct fabrication of a microfluidic chip composed of two high-aspect ratio microfluidic channels with lengths of 3.5 cm and 8 mm in a glass substrate by femtosecond laser micromachining. The fabrication mainly consists of two steps： 1） writing microchannels and microchambers in a porous glass by scanning a tightly focused laser beam; 2） high-temperature annealing of the glass sample to collapse all the nanopores in the glass. Migration of derivatized amino acids is observed in the microfluidic channel by applying electric voltage across the long-migration microchannel.展开更多
Previous strategies for controlling the surface morphologies of polyvinyl alcohol(PVA)-based hydrogels,including freeze-drying and electrospinning,require a posttreatment process,which can affect the final textures an...Previous strategies for controlling the surface morphologies of polyvinyl alcohol(PVA)-based hydrogels,including freeze-drying and electrospinning,require a posttreatment process,which can affect the final textures and properties of the hydrogels.Of particular interest,it is almost impossible to control the surface morphology during the formation of PVA hydrogels using these approaches.The strategy reported in this study used the novel vortex fluidic device(VFD)technology,which for the first time provided an opportunity for one-step fabrication of PVA hydrogel films.PVA hydrogels with different surface morphologies could be readily fabricated using a VFD.By also reducing the crosslinking agent concentration,a self-healing gel with enhanced fracture stress(60%greater than that of traditionally made hydrogel)was achieved.Interestingly,the associated selfhealing property remained unchanged during the 260-s mechanical testing performed with the strain rate of 5%s-1.The VFD can effectively tune the surface morphologies of the PVA-based hydrogels and their associated properties,particularly the self-healing property.展开更多
Centrifugal and shear forces are produced when solids or liquids rotate.Rotary systems and devices that use these forces,such as dynamic thin-film flow technology,are evolving continuously,improve material structure-p...Centrifugal and shear forces are produced when solids or liquids rotate.Rotary systems and devices that use these forces,such as dynamic thin-film flow technology,are evolving continuously,improve material structure-property relationships at the nanoscale,representing a rapidly thriving and expanding field of research high with green chemistry metrics,consolidated at the inception of science.The vortex fluidic device(VFD)provides many advantages over conventional batch processing,with fluidic waves causing high shear and producing large surface areas for micro-mixing as well as rapid mass and heat transfer,enabling reactions beyond diffusion control.Combining these abilities allows for a green and innovative approach to altering materials for various research and industry applications by controlling small-scale flows and regulating molecular and macromolecular chemical reactivity,self-organization phenomena,and the synthesis of novel materials.This review highlights the aptitude of the VFD as clean technology,with an increase in efficiency for a diversity of top-down,bottom-up,and novel material transformations which benefit from effective vortex-based processing to control material structure-property relationships.展开更多
基金financial support from the National Natural Science Foundation of China(Nos.12072196 and 11702172)Science and Technology Commission of Shanghai Municipality(No.19JC1412900)+1 种基金Aeronautics Power Foundation(No.6141B09050393)Key Laboratory of Aerodynamic Noise Control(No.ANCL20190106)extended to this study。
文摘The fluidic oscillator is an instrument that can continuously generate a spatially sweeping jet entirely based on its internal geometry without any moving parts.However,the traditional fluidic oscillator has an inherent limitation,that is,the spreading angle cannot be controlled independently,rather by the jet volume flow rate and internal geometry.Accordingly,two types of fluidic oscillators based on the master-slave design are developed in current study to decouple this correlation.In both designs,the master layer inherits the similar oscillation mechanisms of a sweeping jet,and the slave layer resembles a steady jet channel.The difference between the two designs is that Design A has a short diverging exit in the slave layer,but Design B adds a long interaction chamber in the exit channel to intensify flow instability.The external flow fields and governing oscillation properties of these two designs are experimentally explored with time-resolved Particle Image Velocimetry(PIV),while the internal flow dynamics and driving oscillation mechanisms are numerically investigated.By fixing the total volume flow rate,the jet spreading angle of Design A can be increased smoothly from 0°to above 100°by increasing the proportion of master layer’s flow rate from 0 to 100%.For Design B,the control authority of the master layer is significantly enhanced by adding the interaction chamber in the slave layer.In addition,the added chamber causes notable jet oscillation even when the master layer has none input.
基金supported by the System on Chip Lab grant from the Khalifa University of Science and Technology under awards Nos.8474000134 and 8474000137.
文摘Ionic fluidic devices are gaining interest due to their role in enabling self-powered neuromorphic computing systems.In this study,we present an approach that integrates an iontronic fluidic memristive(IFM)device with low input impedance and a triboelectric nanogenerator(TENG)based on ferrofluid(FF),which has high input impedance.By incorporating contact separation electromagnetic(EMG)signals with low input impedance into our FF TENG device,we enhance the FF TENG’s performance by increasing energy harvesting,thereby enabling the autonomous powering of IFM devices for self-powered computing.Further,replicating neuronal activities using artificial iontronic fluidic systems is key to advancing neuromorphic computing.These fluidic devices,composed of soft-matter materials,dynamically adjust their conductance by altering the solution interface.We developed voltage-controlled memristor and memcapacitor memory in polydimethylsiloxane(PDMS)structures,utilising a fluidic interface of FF and polyacrylic acid partial sodium salt(PAA Na^(+)).The confined ion interactions in this system induce hysteresis in ion transport across various frequencies,resulting in significant ion memory effects.Our IFM successfully replicates diverse electric pulse patterns,making it highly suitable for neuromorphic computing.Furthermore,our system demonstrates synapse-like learning functions,storing and retrieving short-term(STM)and long-term memory(LTM).The fluidic memristor exhibits dynamic synapse-like features,making it a promising candidate for the hardware implementation of neural networks.FF TENG/EMG device adaptability and seamless integration with biological systems enable the development of advanced neuromorphic devices using iontronic fluidic materials,further enhanced by intricate chemical designs for self-powered electronics.
基金supported by the National Natural Science Foundation of China(Nos.61275208 and 61108015)the Program of Shanghai Subject Chief Scientist(No.10XD1404600)
文摘We report the direct fabrication of a microfluidic chip composed of two high-aspect ratio microfluidic channels with lengths of 3.5 cm and 8 mm in a glass substrate by femtosecond laser micromachining. The fabrication mainly consists of two steps： 1） writing microchannels and microchambers in a porous glass by scanning a tightly focused laser beam; 2） high-temperature annealing of the glass sample to collapse all the nanopores in the glass. Migration of derivatized amino acids is observed in the microfluidic channel by applying electric voltage across the long-migration microchannel.
基金International Research Grant(International Laboratory for Health Technologies)of South Australia for supportRaston CL is grateful for support from the Australian Research CouncilMa Y is grateful for the support from the National Natural Science Foundation of China(51679183)。
文摘Previous strategies for controlling the surface morphologies of polyvinyl alcohol(PVA)-based hydrogels,including freeze-drying and electrospinning,require a posttreatment process,which can affect the final textures and properties of the hydrogels.Of particular interest,it is almost impossible to control the surface morphology during the formation of PVA hydrogels using these approaches.The strategy reported in this study used the novel vortex fluidic device(VFD)technology,which for the first time provided an opportunity for one-step fabrication of PVA hydrogel films.PVA hydrogels with different surface morphologies could be readily fabricated using a VFD.By also reducing the crosslinking agent concentration,a self-healing gel with enhanced fracture stress(60%greater than that of traditionally made hydrogel)was achieved.Interestingly,the associated selfhealing property remained unchanged during the 260-s mechanical testing performed with the strain rate of 5%s-1.The VFD can effectively tune the surface morphologies of the PVA-based hydrogels and their associated properties,particularly the self-healing property.
基金Postgraduate Research Scholarship and Flinders University Research Investment Fund 2022,and the Australian Research Council,Grant/Award Numbers:DP200101105,DP200101106。
文摘Centrifugal and shear forces are produced when solids or liquids rotate.Rotary systems and devices that use these forces,such as dynamic thin-film flow technology,are evolving continuously,improve material structure-property relationships at the nanoscale,representing a rapidly thriving and expanding field of research high with green chemistry metrics,consolidated at the inception of science.The vortex fluidic device(VFD)provides many advantages over conventional batch processing,with fluidic waves causing high shear and producing large surface areas for micro-mixing as well as rapid mass and heat transfer,enabling reactions beyond diffusion control.Combining these abilities allows for a green and innovative approach to altering materials for various research and industry applications by controlling small-scale flows and regulating molecular and macromolecular chemical reactivity,self-organization phenomena,and the synthesis of novel materials.This review highlights the aptitude of the VFD as clean technology,with an increase in efficiency for a diversity of top-down,bottom-up,and novel material transformations which benefit from effective vortex-based processing to control material structure-property relationships.
