An approach was described to produce a wound area in vitro using laminar flow technique to selectively remove cells in micro fluidic channels. Cell migration which plays an important role in the process of wound heali...An approach was described to produce a wound area in vitro using laminar flow technique to selectively remove cells in micro fluidic channels. Cell migration which plays an important role in the process of wound healing can be observed dynamically by this method. In order to prove our system, we have studied its properties by injecting NIH-3T3 cells into main channel and added several reagents to observe the mediatory influence. The results reveal that fibroblast growth factor-2（FGF-2）, insulin-like growth factor 1（IGF-Ⅰ）, platelet-derived growth factor BB（PDGF-BB） and ascorbic acid（Vc） groups can promote cell migration compared with the control group. But the average migration distance was diminished in dexamethasone group. It can be concluded that this system can be used to analyze the process of wound healing.展开更多
In this paper, a silicon-based neural probe with microfluidic channels was developed and evaluated. The probe can deliver chemicals or drugs to the target neurons while simultaneously recording the electrical action o...In this paper, a silicon-based neural probe with microfluidic channels was developed and evaluated. The probe can deliver chemicals or drugs to the target neurons while simultaneously recording the electrical action of these neurons extracellularly. The probe was fabricated by double-sided deep reactive ion etching （DRIE） from a silicon-on-insulator （SO1） wafer. The flu- idic channels were formed with V-shape groove etching on the silicon probe and sealed with silicon nitride and parylene-C. The shank of the probe is 4 mm long and 120 ~tm wide. The thickness of the probe is 100 ~tm. The probe has two fluidic chan- nels and two recording sites. The microfluidic channels can withstand a pressure drop as much as 30 kPa and the flow resisti ity of the microfluidic channel is 0.13 μL min-1 kPa-1, The typical impedance of the neural electrode is 32.3 kΩ at 1 kHz at room temperature.展开更多
The transports of the dynamic biochemical signals in the non-reversing pulsatile flows in the mixing microchannel of a Y-shaped microfluidic device are ana- lyzed. The results show that the mixing micro-channel acts a...The transports of the dynamic biochemical signals in the non-reversing pulsatile flows in the mixing microchannel of a Y-shaped microfluidic device are ana- lyzed. The results show that the mixing micro-channel acts as a low-pass filter, and the biochemical signals are nonlinearly modulated by the pulsatile flows, which depend on the biochemical signal frequency, the flow signal frequency, and the biochemical signal transporting distance. It is concluded that, the transfer characteristics of the dynamic biochemical signals, which are transported in the time-varying flows, should be carefully considered for better loading biochemical signals on the cells cultured on the bottom of the microfluidic channel.展开更多
This paper presents an analysis of dispersion of dynamic biochemical signals in steady flow in a shallow Y-type microfluidic channel. A method is presented to control the flow widths of two steady flows in the Y-type ...This paper presents an analysis of dispersion of dynamic biochemical signals in steady flow in a shallow Y-type microfluidic channel. A method is presented to control the flow widths of two steady flows in the Y-type microchannel from two inlets.The transfer function for the Y-type microchannel is given by solving the governing equation for the Taylor-Aris dispersion in the microchannel. The amplitude-frequency and phase-frequency relations are provided which show that a shallow Y-type microchannel acts as a low-pass filter. The transports of different dynamic biochemical signals are investigated. In comparison with a fully mixing microfluidic channel, the magnitudes of the dynamic signals at the outlets in a Y-type microchannel are much smaller than those in a fully mixing microchannel, which demonstrates that the amplitude attenuation in a Y-type microchannel is larger than that of a fully mixing microchannel due to the transverse molecular diffusion. In order to control the desired signal in a microchannel, the solution of the inverse problem for the channel is also presented.展开更多
Monitoring taste-inducing ions and molecules continuously in liquids or solutions is of great considerable matter for the realization of the electronic tongue(E-tongue).Particularly from the five major tastes,the high...Monitoring taste-inducing ions and molecules continuously in liquids or solutions is of great considerable matter for the realization of the electronic tongue(E-tongue).Particularly from the five major tastes,the highly selective,sensitive detection of Na^(+)in real-time is prioritized.Prioritization is due to the saltiness of food is the key ingredient in most meals.Nevertheless,existing Na^(+)detecting devices have relatively low performances of selectivity,sensitivity,and lack of on–off functions.Additionally,conventional devices significantly deteriorate in capac-ity due to repetitive usage or lifetime shortage by degradation of the sensing mate-rial.Herein,a graphene-based channel was rationally designed by the facile decoration of Calix[4]arene and Nafion to address this issue.They act as a receptor and a molecular sieve,respectively,to enhance selectivity and sensitivity and elon-gate the life expectancy of the device.This device was merged with a microfluidic channel to control the injection and withdrawal of solutions to fulfill dynamic on–off functions.The fabricated device has highly selective,sensitive Na^(+)detection properties compared to other 10 molecule/ionic species.Dynamic on–off functions of the device were available,also possesses a long lifespan of at least 220 days.Additionally,it can precisely discriminate real beverages containing Na^(+),which can be observed by principal component analysis plot.These features offer the possibility of ascending to a platform for E-tongues in near future.展开更多
Efficient portable wearable sweat sensors allow the long-term monitoring of changes in the status of biomarkers in sweat,which can be useful in diagnosis,medication,and nutritional assessment.In this study,we designed...Efficient portable wearable sweat sensors allow the long-term monitoring of changes in the status of biomarkers in sweat,which can be useful in diagnosis,medication,and nutritional assessment.In this study,we designed and tested a wireless,battery-free,flexible,self-pumping sweat-sensing system that simultaneously tracks levodopa and vitamin C levels in human sweat and detects body temperature.The system includes a microfluidic chip with a self-driven pump and anti-reflux valve,a flexible wireless circuit board,and a purpose-designed smartphone app.The microfluidic chip is used for the efficient collection of sweat and the drainage of excess sweat.The dual electrochemical sensing electrodes in the chip are modified with functional materials and appropriate enzymatic reagents,achieving excellent selectivity and stability.The sensitivities of the levodopa sensor and the vitamin C sensor are 0.0073 and 0.0018μA·μM^(-1),respectively,and the detection correlation coefficients of both exceed 0.99.Both sensors have a wide linear detection range of 0–100 and 0–1000μM,respectively,and low detection limits of 0.28 and 17.9μM,respectively.The flexible wireless circuit board is equipped with the functions of wireless charging,electrical signal capture and processing,and wireless transmission.The data recorded from each sensor are displayed on a smartphone via a self-developed app.A series of experimental results confirmed the reliability of the sweat-sensing system in noninvasively monitoring important biomarkers in the human body and its potential utility in the comprehensive assessment of biological health.展开更多
A simple and efficient method using enzyme immobilized microfluidic channel as open tubular microreactor was designed for amperometric detection of glucose. The microreactor was composed of a polydimethylsilicone/ gla...A simple and efficient method using enzyme immobilized microfluidic channel as open tubular microreactor was designed for amperometric detection of glucose. The microreactor was composed of a polydimethylsilicone/ glass hybrid device with three reservoirs, a cooling cave and a 6 cm capillary with a sampling fracture as micro-channel. The microchannel was further modified by thermal polymerization, followed by covalently attaching with glucose oxidase. Through fracture sampling and electrochromatography separation, the production via enzymatic reaction was determinated by Pt electrode at the end of capillary. The linear range for the detection of glucose was 0.05--7.5 mmol·L-1 with detection limit of 23μmol.L-1 The inter-and intra-chip reproducibilities for determination of 2.5 mmol-L-1 glucose were 98.5% （n=5） and 96.0% （n=5）, respectively. With the advantage of flexible assembly, rapid efficiency, good stability and low-cost, this microreactor provided a potential platform for estab- lishing a portable enzyme-based chemical detection system in practical application.展开更多
This paper proposes a highly sensitive,compact,and low-cost optical fiber salinity sensor based on the Mach-Zehnder interferometer.The sensor is constructed using a single mode fiber(SMF)-no-core fiber-double-C fiber(...This paper proposes a highly sensitive,compact,and low-cost optical fiber salinity sensor based on the Mach-Zehnder interferometer.The sensor is constructed using a single mode fiber(SMF)-no-core fiber-double-C fiber(DCF)-NCF-SMF structure,with the DCF prepared by etching the dual side-hole fiber with HF acid.The DCF’s large-size exposed microfluidic channels solve the previous microstructured optical fiber’s challenging liquid filling and replacement problems.Theoretical simulations and experiments demonstrate that the sensor is suitable for high-sensitivity salinity measurement.The sensor exhibits a high salinity sensitivity of-2.26 nm/‰ in the salinity range of 10‰-50‰,as demonstrated by the experimental results.Additionally,the sensor exhibits some fascinating characteristics,including high repeatability,hysteresis,reversibility,and stability.展开更多
基金Supported by the National Natural Science Foundation of China(Nos.21071148,21175140)
文摘An approach was described to produce a wound area in vitro using laminar flow technique to selectively remove cells in micro fluidic channels. Cell migration which plays an important role in the process of wound healing can be observed dynamically by this method. In order to prove our system, we have studied its properties by injecting NIH-3T3 cells into main channel and added several reagents to observe the mediatory influence. The results reveal that fibroblast growth factor-2（FGF-2）, insulin-like growth factor 1（IGF-Ⅰ）, platelet-derived growth factor BB（PDGF-BB） and ascorbic acid（Vc） groups can promote cell migration compared with the control group. But the average migration distance was diminished in dexamethasone group. It can be concluded that this system can be used to analyze the process of wound healing.
基金supported by the National Basic Research Program of China("973" Project) (Grant Nos. 2011CB933203, 2011CB933102)the National Natural Science Foundation of China (Grant Nos.31070965,90820002,60877035,60976026 and 61076023)
文摘In this paper, a silicon-based neural probe with microfluidic channels was developed and evaluated. The probe can deliver chemicals or drugs to the target neurons while simultaneously recording the electrical action of these neurons extracellularly. The probe was fabricated by double-sided deep reactive ion etching （DRIE） from a silicon-on-insulator （SO1） wafer. The flu- idic channels were formed with V-shape groove etching on the silicon probe and sealed with silicon nitride and parylene-C. The shank of the probe is 4 mm long and 120 ~tm wide. The thickness of the probe is 100 ~tm. The probe has two fluidic chan- nels and two recording sites. The microfluidic channels can withstand a pressure drop as much as 30 kPa and the flow resisti ity of the microfluidic channel is 0.13 μL min-1 kPa-1, The typical impedance of the neural electrode is 32.3 kΩ at 1 kHz at room temperature.
基金Project supported by the National Natural Science Foundation of China(Nos.11172060 and11672065)
文摘The transports of the dynamic biochemical signals in the non-reversing pulsatile flows in the mixing microchannel of a Y-shaped microfluidic device are ana- lyzed. The results show that the mixing micro-channel acts as a low-pass filter, and the biochemical signals are nonlinearly modulated by the pulsatile flows, which depend on the biochemical signal frequency, the flow signal frequency, and the biochemical signal transporting distance. It is concluded that, the transfer characteristics of the dynamic biochemical signals, which are transported in the time-varying flows, should be carefully considered for better loading biochemical signals on the cells cultured on the bottom of the microfluidic channel.
基金National Natural Science Foundation of Chinagrant number:11172060the Fundamental Research Funds for the Central Universities in China
文摘This paper presents an analysis of dispersion of dynamic biochemical signals in steady flow in a shallow Y-type microfluidic channel. A method is presented to control the flow widths of two steady flows in the Y-type microchannel from two inlets.The transfer function for the Y-type microchannel is given by solving the governing equation for the Taylor-Aris dispersion in the microchannel. The amplitude-frequency and phase-frequency relations are provided which show that a shallow Y-type microchannel acts as a low-pass filter. The transports of different dynamic biochemical signals are investigated. In comparison with a fully mixing microfluidic channel, the magnitudes of the dynamic signals at the outlets in a Y-type microchannel are much smaller than those in a fully mixing microchannel, which demonstrates that the amplitude attenuation in a Y-type microchannel is larger than that of a fully mixing microchannel due to the transverse molecular diffusion. In order to control the desired signal in a microchannel, the solution of the inverse problem for the channel is also presented.
基金National R&D Program,Grant/Award Number:2021M3H4A3A02086430Nano Material Technology Development Program,Grant/Award Number:2022M3H4A1A01011993+3 种基金Ministry of Science and ICT,South KoreaResearch Institute of Advanced Materials(RIAM)Inter University Semiconductor Research Center(ISRC)National Instrumentation Center for Environmental Management(NICEM)。
文摘Monitoring taste-inducing ions and molecules continuously in liquids or solutions is of great considerable matter for the realization of the electronic tongue(E-tongue).Particularly from the five major tastes,the highly selective,sensitive detection of Na^(+)in real-time is prioritized.Prioritization is due to the saltiness of food is the key ingredient in most meals.Nevertheless,existing Na^(+)detecting devices have relatively low performances of selectivity,sensitivity,and lack of on–off functions.Additionally,conventional devices significantly deteriorate in capac-ity due to repetitive usage or lifetime shortage by degradation of the sensing mate-rial.Herein,a graphene-based channel was rationally designed by the facile decoration of Calix[4]arene and Nafion to address this issue.They act as a receptor and a molecular sieve,respectively,to enhance selectivity and sensitivity and elon-gate the life expectancy of the device.This device was merged with a microfluidic channel to control the injection and withdrawal of solutions to fulfill dynamic on–off functions.The fabricated device has highly selective,sensitive Na^(+)detection properties compared to other 10 molecule/ionic species.Dynamic on–off functions of the device were available,also possesses a long lifespan of at least 220 days.Additionally,it can precisely discriminate real beverages containing Na^(+),which can be observed by principal component analysis plot.These features offer the possibility of ascending to a platform for E-tongues in near future.
基金supported by the National Natural Science Foundation of China(No.32171373)the Projects of International Cooperation and Exchanges NSFC(No.82020108017)+1 种基金the Natural Science Foundation of Shanghai(No.23ZR1414500)the Medical Engineering Cross Project of SJTU(No.YG2021QN141).
文摘Efficient portable wearable sweat sensors allow the long-term monitoring of changes in the status of biomarkers in sweat,which can be useful in diagnosis,medication,and nutritional assessment.In this study,we designed and tested a wireless,battery-free,flexible,self-pumping sweat-sensing system that simultaneously tracks levodopa and vitamin C levels in human sweat and detects body temperature.The system includes a microfluidic chip with a self-driven pump and anti-reflux valve,a flexible wireless circuit board,and a purpose-designed smartphone app.The microfluidic chip is used for the efficient collection of sweat and the drainage of excess sweat.The dual electrochemical sensing electrodes in the chip are modified with functional materials and appropriate enzymatic reagents,achieving excellent selectivity and stability.The sensitivities of the levodopa sensor and the vitamin C sensor are 0.0073 and 0.0018μA·μM^(-1),respectively,and the detection correlation coefficients of both exceed 0.99.Both sensors have a wide linear detection range of 0–100 and 0–1000μM,respectively,and low detection limits of 0.28 and 17.9μM,respectively.The flexible wireless circuit board is equipped with the functions of wireless charging,electrical signal capture and processing,and wireless transmission.The data recorded from each sensor are displayed on a smartphone via a self-developed app.A series of experimental results confirmed the reliability of the sweat-sensing system in noninvasively monitoring important biomarkers in the human body and its potential utility in the comprehensive assessment of biological health.
文摘A simple and efficient method using enzyme immobilized microfluidic channel as open tubular microreactor was designed for amperometric detection of glucose. The microreactor was composed of a polydimethylsilicone/ glass hybrid device with three reservoirs, a cooling cave and a 6 cm capillary with a sampling fracture as micro-channel. The microchannel was further modified by thermal polymerization, followed by covalently attaching with glucose oxidase. Through fracture sampling and electrochromatography separation, the production via enzymatic reaction was determinated by Pt electrode at the end of capillary. The linear range for the detection of glucose was 0.05--7.5 mmol·L-1 with detection limit of 23μmol.L-1 The inter-and intra-chip reproducibilities for determination of 2.5 mmol-L-1 glucose were 98.5% （n=5） and 96.0% （n=5）, respectively. With the advantage of flexible assembly, rapid efficiency, good stability and low-cost, this microreactor provided a potential platform for estab- lishing a portable enzyme-based chemical detection system in practical application.
基金This work was supported in part by the National Natural Science Foundation of China(Grants No.61933004 and 62075036)the National Natural Science Foundation of Liaoning Province(Grant No.2020-YQ-04)+2 种基金the Fundamental Research Funds for the Central Universities(Grants No.N2002019 and N2104019)the State Key Laboratory of Synthetical Automation for Process Industries(Grant No.2013ZCX09)the Hebei Natural Science Foundation(Grant No.F2020501040).
文摘This paper proposes a highly sensitive,compact,and low-cost optical fiber salinity sensor based on the Mach-Zehnder interferometer.The sensor is constructed using a single mode fiber(SMF)-no-core fiber-double-C fiber(DCF)-NCF-SMF structure,with the DCF prepared by etching the dual side-hole fiber with HF acid.The DCF’s large-size exposed microfluidic channels solve the previous microstructured optical fiber’s challenging liquid filling and replacement problems.Theoretical simulations and experiments demonstrate that the sensor is suitable for high-sensitivity salinity measurement.The sensor exhibits a high salinity sensitivity of-2.26 nm/‰ in the salinity range of 10‰-50‰,as demonstrated by the experimental results.Additionally,the sensor exhibits some fascinating characteristics,including high repeatability,hysteresis,reversibility,and stability.
