ANALYTICAL SCIENCES
·
2020
·Vol. 36
·期 8
·953-957
·
IF 2.049
Tian Shumei,Zhang Wenli,Shi Jinwei,Guo Zixian,Li Ming
Nanochannel plastic membranes are excellent materials for electroosmotic pump (EOP) elements owing to their surface charge properties, flexibility and cost-effectiveness. However, the surface charge properties of plastics are inferior to those of silicate-based materials. This paper reports a performance-enhanced EOP equipped with a glassified track-etch polycarbonate membrane (PC), which has a nanochannel surface covered by allylhydridopolycarbosilane (AHPCS). The effects of applied voltage, pH and membrane pore size on the electroosmotic flow velocity, along with a comparative study of the EOP with coated and pure membranes were investigated. It was found that when low DC voltage (10 - 40 V) was applied to both ends of the pump, the magnitude of the electroosmotic flow was linearly proportional to the voltage when the pore size of the membrane was less than 600 nm. A higher flow rate was obtained with larger pore size membranes. Compared with the uncoated film, the coated one showed faster electroosmosis velocity, with higher stability under the same conditions. For pH 10.0 buffer solution, a flow rate of 89.13 μL/min was obtained in the modified membrane-based EOP with excellent repeatability and durability, while the flow rate was only 37.89 μL/min in the bare PC membrane under 20 V. In order to demonstrate the performance of the developed EOP, the EOP was used for microcomplexometric titration to determine actual tap water hardness. The measured results were highly consistent with the results of a conventional complexometric titration methed. The EOP with an AHPCS-coated plastic membrane expanded the application range to harsh condition solutions, such as high-concentration acids or bases.
研究领域:
材料科学
·
分析化学
✓ 已验证
DOI
高影响因子
LAB ON A CHIP
·
2024
·Vol. 24
·期 4
·896-903
·
IF 6.1
Qian Li,Pan Zhang,Zi Ye,Huimin Zhang,Xiao Sun,Lin Gui
The application of liquid metal in a microfluidic system enables the fabrication of highly integrated on-chip electroosmotic micropumps (EOPs). In this work, a low-voltage driveable integrated parallel EOP cluster drive system is proposed. This system consists of two layers, a branch-channel layer and a trunk-channel layer. The lower branch-channel layer contains separate parallel pumping channels and a pair of comb liquid metal electrodes. The separated branch channels are connected together through the trunk channels in the upper layer. With this structural arrangement, the parallel micropumps form an integrated micropump cluster for larger pumping capacity. The distance between the pumping channel and the electrode next to it is controlled to 20 μm. To guide the pump design, parametric studies are performed and fully discussed. According to the experimental results, the micropump cluster can be driven at a low voltage of 0.5 V, and the flow rate reaches 274 nL min−1 at 5 V. In addition, the paper finally proposes an electrode protection strategy and an integrated pump-valve drive system which is expected to solve the shortcoming of electroosmotic pumps in terms of long-time storage and driving.
CAS / MDL:
研究领域:
微纳米技术
·
生物医学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ELECTROPHORESIS
·
2025
·
IF 2.5
Xionghui Li,Haonan Li,Xuanying Liang,Zejingqiu Chen,Muyang Zhang,Qinghao He,Jie Zhou,Zitao Feng,Yeqian Liu,Xinyi Chen,Huilin Chen,Zitong Ye,Ziwei Huang,Xingwei Zhang,Huiru Zhang,Lok Ting Chu,Weijin Guo
Flow velocity control is of great interest for passive microfluidic devices that are used in point-of-care diagnostics. Various methods have been developed for the flow velocity control of microfluidic paper-based analytical devices (µPADs), whereas fewer attempts have been made for microfluidic thread-based analytical devices (µTADs). In this research, we attempt to control the flow velocity in cotton thread-based µTADs with electroosmotic pumping. Utilizing electroosmotic pumps, the flow velocity in the cotton thread-based µTADs can be decreased or increased by 13% and 106%, respectively. Moreover, the dynamic control of the flow velocity in the cotton thread-based µTADs is achieved by adjusting the real-time magnitude and direction of the voltage. Furthermore, we demonstrate that electroosmotic pumps can be used to overcome the hydrophobic valves in the cotton thread-based µTADs. We show that the delivery sequence of different liquid samples for a three-branch µTAD can be controlled. Finally, we show the potential application in lithium detection with a colorimetric assay. This method for flow velocity control shows promise for customizing the flow velocity and reaction time of cotton thread-based µTADs, and this method can potentially increase the sensitivity of detection.
研究领域:
分析化学
·
生物医学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Nano
·
2023
·
IF 17.1
Xinghao Hu,Fengrui Zhang,Runmin Liu,Jinchang Jiang,Xianfu Bao,Yiming Liang
Previous electrochemically powered yarn muscles cannot be usefully operated between extreme negative and extreme positive potentials, since generated stresses during anion injection and cation injection partially cancel because they are in the same direction. We here report an ionomer-infiltrated hybrid carbon nanotube (CNT) yarn muscle that shows unipolar stress behavior in the sense that stress generation between extreme potentials is additive, resulting in an enhanced stress generation. Moreover, the stress generated by this muscle unexpectedly increases with the potential scan rate, which contradicts the fact that scan-rate-induced stress decreases for neat CNT muscles. It is revealed by the electro-osmotic pump effect that the effective ion size injected into the muscle increases with an increase in the scan rate. We demonstrate an electrochemically powered gel-elastomer-yarn muscle adhesive that generates and delivers muscle-contraction-mimicking stimulation to a target tissue.
研究领域:
材料科学
·
生物医学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ELECTROPHORESIS
·
2015
·Vol. 36
·期 23
·2881-2887
·
IF 3.028
Yue Wu,Wenpeng Zhang,Ying Chen,Zilin Chen
In this work, a novel molecularly imprinted polymer (MIP) monolithic column with integrated in-column electroosmotic pump (EOP) was designed and successfully prepared to facilitate the capillary chromatography with MIP column. A silica-based EOP was synthesized at the detection end of the MIP monolithic capillary column by so-gel to provide the hydrodynamic driven force for the capillary chromatography. Because of large surface area and low fluidic resistance of the silica monolith,a strong and steady EOF was generated by silica-based EOP, indicating that the EOP was quite compatible with MIP capillary column. With the sufficient EOF provided by EOP, the electro-driven based capillary chromatographic separation of nitrophenol isomers was achieved in 4-vinylpyridine-based MIP monolithic capillary, which was originally proved infeasible because of the EOF shortage. No significant influence upon the specific recognition of the MIP was found due to the setting of EOP after the detection window of the column. The influence of experimental parameters on the EOF such as voltage and pH value of running buffer was investigated. The column was also evaluated by capillary liquid chromatographic mode to compare with EOP-driven capillary chromatography. Higher column efficiency was obtained by EOP-driven separation with improved peak shape. The results suggested that EOP-supported technique would be a good way to solve the problem of weak EOF generation in electro-driven capillary chromatography.
研究领域:
分析化学
·
色谱技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ELECTROPHORESIS
·
2019
·
IF 2.754
Qian Yang,Bin Su,Yafeng Wang,Wanhao Wu
In this work, an efficient electroosmotic pump (EOP) based on the ultrathin silica nanoporous membrane (u-SNM), which can drive the motion of fluid under the operating voltage as low as 0.2 V, has been fabricated. Thanks to the ultrathin thickness of u-SNM (∼75 nm), the effective electric field strength across u-SNM could be as high as 8.27 × 10 5 V m −1 in 0.4 M KCl when 1.0 V of voltage was applied. The maximum normalized electroosmotic flow (EOF) rate was as high as 172.90 mL/min/cm 2 /V, which was larger than most of other nanoporous membrane based EOPs. In addition to the ultrathin thickness, the high porosity of this membrane (with a pore density of 4 × 10 12 cm −2 , corresponding to a porosity of 16.7%) also contribute to such a high EOF rate. Moreover, the EOF rate was found to be proportional to both the applied voltage and the electrolyte concentration. Because of small electrokinetic radius of u-SNM arising from its ultrasmall pore size (ca. 2.3 nm in diameter), the EOF rate increased with increasing the electrolyte concentration and reached the maximum at a concentration of 0.4 M. This dependence was rationalized by the variations of both zeta potential and electrokinetic radius with the electrolyte concentration.
研究领域:
材料科学
·
纳米技术
·
生物医学工程
✓ 已验证
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）