Flexible microfluidic device for mechanical property characterization of soft viscoelastic solids such as bacterial biofilms.
Flexible microfluidic device for mechanical property characterization of soft viscoelastic solids such as bacterial biofilms.
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DOI：
10.1021/la803413x
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发表时间：
2009-07-07
期刊：
影响因子：
--
通讯作者：
Solomon MJ
中科院分区：
文献类型：
--
作者：
Hohne DN;Younger JG;Solomon MJ
我们介绍了一种灵活的微流体装置来表征软粘弹性固体，如细菌生物膜的机械性能。在该装置中，通过将固定压力施加到与试样接触的薄的柔性聚二甲基硅氧烷（PDMS）膜上，将应力施加到试样上。通过对位于测试区域上方的微加工空气通道加压来施加应力。通过用共聚焦激光扫描显微镜测量膜偏转来量化由所施加的应力引起的应变。偏转由PDMS膜和试样的粘弹性决定。通过比较PDMS膜机械性能的有限元分析和独立（对照）测量，量化膜和测试材料对测量变形的相对贡献。采用柔性微流控流变仪对结冷胶和细菌生物膜两种软质材料的稳态弹性模量和瞬态应变回缩进行了表征。结冷胶溶液的线弹性模量和粘弹性松弛时间的测量结果与传统的机械流变仪的结果吻合得很好。表皮葡萄球菌和肺炎克雷伯菌生物膜的线性杨氏模量分别为3.2kPa和1.1kPa，而用常规方法无法测量。表皮生物被膜为13.8s。此外，在所有研究的生物膜中观察到应变硬化。最后，该方法的设计参数和检测限表明，该装置能够表征弹性模量在102 - 105 Pa范围内的软粘弹性固体。柔性微流体流变仪解决了诸如生物材料、食品和消费品等领域中常见的软粘弹性固体的机械性能表征的需求。它只需要约200 pL的测试样本。
We introduce a flexible microfluidic device to characterize the mechanical properties of soft viscoelastic solids such as bacterial biofilms. In the device, stress is imposed on a test specimen by application of a fixed pressure to a thin, flexible poly(dimethyl siloxane) (PDMS) membrane that is in contact with the specimen. The stress is applied by pressurizing a microfabricated air channel located above the test area. The strain resulting from the applied stress is quantified by measuring the membrane deflection with a confocal laser-scanning microscope. The deflection is governed by the viscoelastic properties of the PDMS membrane and of the test specimen. The relative contributions of the membrane and test material to the measured deformation are quantified by comparing a finite element analysis and an independent (control) measurement of the PDMS membrane mechanical properties. The flexible microfluidic rheometer was used to characterize both the steady-state elastic modulus and transient strain recoil of two soft materials: gellan gums and bacterial biofilms. The measured linear elastic moduli and viscoelastic relaxation times of gellan gum solutions were in good agreement with the results of conventional mechanical rheometry. The linear Young’s moduli of biofilms of Staphylococcus epidermidis and Klebsiella pneumoniae, which could not be measured using conventional methods, were found to be 3.2 kPa and 1.1 kPa, respectively, and the relaxation time of the S. epidermidis biofilm was 13.8 s. Additionally, strain hardening was observed in all the biofilms studied. Finally, design parameters and detection limits of the method show that the device is capable of characterizing soft viscoelastic solids with elastic moduli in the range of 102 – 105 Pa. The flexible microfluidic rheometer addresses a need for mechanical property characterization of soft viscoelastic solids common in fields such as biomaterials, food and consumer products. It requires only ~ 200 pL of test specimen.
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影响因子：
3.3
作者：
Clasen, Christian;Gearing, Brian P.;McKinley, Gareth H.
通讯作者：
McKinley, Gareth H.
影响因子：
8.6
作者：
Crocker, JC;Valentine, MT;Weitz, DA
通讯作者：
Weitz, DA
DOI：
10.1002/nme.2192
发表时间：
2008-04-30
影响因子：
2.9
作者：
Krysl, P.;Cranford, T. W.;Hildebrand, J. A.
通讯作者：
Hildebrand, J. A.
影响因子：
8.6
作者：
Mason, TG;Ganesan, K;Kuo, SC
通讯作者：
Kuo, SC
影响因子：
2.2
作者：
Cense, A. W.;Peeters, E. A. G.;van Dongen, M. E. H.
通讯作者：
van Dongen, M. E. H.