@book {1586129,
	title = {Microgel Suspensions: Fundamentals and Applications},
	year = {2011},
	pages = {484},
	publisher = {Wiley-VCH},
	organization = {Wiley-VCH},
	edition = {1},
	abstract = {Providing a vital link between chemistry and physics on the nanoscale, this book offers concise coverage of the entire topic in five major sections, beginning with synthesis of microgel particles and continuing with their physical properties. The phase behavior and dynamics of resulting microgel suspensions feature in the third section, followed by their mechanical properties. It concludes with detailed accounts of numerous industrial, commercial and medical applications.},
	url = {https://onlinelibrary.wiley.com/doi/book/10.1002/9783527632992},
	editor = {Fernandez-Nieves, Alberto and Wyss, Hans W. and Mattsson, Johan and Weitz, DavidA.}
}
@article {156461,
	title = {Enhanced encapsulation of actives in self-sealing microcapsules by precipitation in capsule shells},
	journal = {Langmuir},
	volume = {27},
	number = {23},
	year = {2011},
	pages = {13988-13991},
	abstract = {Microcapsules with core-shell structures are excellent vehicles for the encapsulation of active ingredients; however, the actives often leak out of these structures over time, without observable damage to them. We present a novel approach to enhancing the encapsulation of active ingredients inside microcapsules. We use two components that can form solid precipitates upon mixing and add one each to the microcapsule core and to the continuous phase. The components diffuse through the shell in the same manner as the actives, but upon meeting, they precipitate to form solid particles within the shell; this significantly reduces leakage through the shell of the microcapsules. We show that the reduction in the leakage of actives is due to the blockage of channels or pores that exist in the shell of the capsules by the solid precipitates.},
	url = {https://pubs.acs.org/doi/10.1021/la2034774},
	author = {Zhao, Yuanjin and Shum, Ho Cheung and Adams, Laura L. A. and Sun, Bing Jie and Holtze, Christian and Gu, Zhongze and Weitz, David A}
}
@article {156466,
	title = {Microfluidic generation of multifunctional quantum dot barcode particles},
	journal = {Journal of the American Chemical Society},
	volume = {133},
	number = {23},
	year = {2011},
	pages = {8790-8793},
	abstract = {We develop a new strategy to prepare quantum dot (QD) barcode particles by polymerizing double-emulsion droplets prepared in capillary microfluidic devices. The resultant barcode particles are composed of stable QD-tagged core particles surrounded by hydrogel shells. These particles exhibit uniform spectral characteristics and excellent coding capability, as confirmed by photoluminescence analyses. By using double-emulsion droplets with two inner droplets of distinct phases as templates, we have also fabricated anisotropic magnetic barcode particles with two separate cores or with a Janus core. These particles enable optical encoding and magnetic separation, thus making them excellent functional barcode particles in biomedical applications.},
	url = {https://pubs.acs.org/doi/10.1021/ja200729w},
	author = {Zhao, Yuanjin and Shum, Ho Cheung and Chen, Haosheng and Adams, Laura L. A. and Gu, Zhongze and Weitz, David A}
}
@article {156371,
	title = {Biophysical properties of normal and diseased renal glomeruli},
	journal = {American Journal of Physiology-Cell Physiology},
	volume = {300},
	number = {3},
	year = {2011},
	pages = {C397-C405},
	abstract = {
	The mechanical properties of tissues and cells including renal glomeruli are important determinants of their differentiated state, function, and responses to injury but are not well characterized or understood. Understanding glomerular mechanics is important for understanding renal diseases attributable to abnormal expression or assembly of structural proteins and abnormal hemodynamics. We use atomic force microscopy (AFM) and a new technique, capillary micromechanics, to measure the elastic properties of rat glomeruli. The Young{\textquoteright}s modulus of glomeruli was 2,500 Pa, and it was reduced to 1,100 Pa by cytochalasin and latunculin, and to 1,400 Pa by blebbistatin. Cytochalasin or latrunculin reduced the F/G actin ratios of glomeruli but did not disrupt their architecture. To assess glomerular biomechanics in disease, we measured the Young{\textquoteright}s moduli of glomeruli from two mouse models of primary glomerular disease, Col4a3(-/-) mice (Alport model) and Tg26(HIV/nl) mice (HIV-associated nephropathy model), at stages where glomerular injury was minimal by histopathology. Col4a3(-/-) mice express abnormal glomerular basement membrane proteins, and Tg26(HIV/nl) mouse podocytes have multiple abnormalities in morphology, adhesion, and cytoskeletal structure. In both models, the Young{\textquoteright}s modulus of the glomeruli was reduced by 30\%. We find that glomeruli have specific and quantifiable biomechanical properties that are dependent on the state of the actin cytoskeleton and nonmuscle myosins. These properties may be altered early in disease and represent an important early component of disease. This increased deformability of glomeruli could directly contribute to disease by permitting increased distension with hemodynamic force or represent a mechanically inhospitable environment for glomerular cells.

},
	url = {https://pubmed.ncbi.nlm.nih.gov/21123730/},
	author = {Wyss, Hans M. and Henderson, Joel M. and Byfield, Fitzroy J. and Bruggeman, Leslie A. and Ding, Yaxian and Huang, Chunfa and Suh, Jung Hee and Franke, Thomas and Mele, Elisa and Pollak, Martin R. and Miner, Jeffrey H. and Paul A. Janmey and Weitz, David A and Miller, R. Tyler}
}
@article {156391,
	title = {Nonlinear viscoelasticity of actin transiently cross-linked with mutant alpha-actinin-4},
	journal = {Journal of Molecular Biology},
	volume = {411},
	number = {5},
	year = {2011},
	pages = {1062-1071},
	abstract = {Filamentous actin and associated actin binding proteins play an essential role in governing the mechanical properties of eukaryotic cells. They can also play a critical role in disease; for example, mutations in alpha-actinin-4 (Actn4), a dynamic actin cross-linking protein, cause proteinuric disease in humans and mice. Amino acid substitutions strongly affect the binding affinity and protein structure of Actn4. To study the physical impact of such substitutions on the underlying cytoskeletal network, we examine the bulk mechanical behavior of in vitro actin networks cross-linked with wild-type and mutant Actn4. These networks exhibit a complex viscoelastic response and are characterized by fluid-like behavior at the longest timescales, a feature that can be quantitatively accounted for through a model governed by dynamic cross-linking. The elastic behavior of the network is highly nonlinear, becoming much stiffer with applied stress. This nonlinear elastic response is also highly sensitive to the mutations of Actn4. In particular, we observe that actin networks cross-linked with Actn4 bearing the disease-causing K255E mutation are more brittle, with a lower breaking stress in comparison to networks cross-linked with wild-type Actn4. Furthermore, a mutation that ablates the first actin binding site (ABS1) in Actn4 abrogates the network{\textquoteright}s ability to stress-stiffen is standard nomenclature. These changes in the mechanical properties of actin networks cross-linked with mutant Actn4 may represent physical determinants of the underlying disease mechanism in inherited focal segmental glomerulosclerosis. (C) 2011 Elsevier Ltd. All rights reserved.},
	url = {https://www.sciencedirect.com/science/article/abs/pii/S0022283611007376?via\%3Dihub},
	author = {Yao, Norman Y. and Becker, Daniel J. and Broedersz, Chase P. and Depken, Martin and MacKintosh, Frederick C and Pollak, Martin R. and Weitz, David A}
}
@article {156326,
	title = {Biofilms as complex fluids},
	journal = {Mrs Bulletin},
	volume = {36},
	number = {5},
	year = {2011},
	pages = {385-391},
	abstract = {Bacterial biofilms are interface-associated colonies of bacteria embedded in an extracellular matrix that is composed primarily of polymers and proteins. They can be viewed in the context of soft matter physics: the rigid bacteria are analogous to colloids, and the extracellular matrix is a cross-linked polymer gel. This perspective is beneficial for understanding the structure, mechanics, and dynamics of the biofilm. Bacteria regulate the water content of the biofilm by controlling the composition of the extracellular matrix, and thereby controlling the mechanical properties. The mechanics of well-defined soft materials can provide insight into the mechanics of biofilms and, in particular, the viscoelasticity. Furthermore, spatial heterogeneities in gene expression create heterogeneities in polymer and surfactant production. The resulting concentration gradients generate forces within the biofilm that are relevant for biofilm spreading and survival.},
	url = {https://link.springer.com/article/10.1557/mrs.2011.71},
	author = {Wilking, James N. and Angelini, Thomas E. and Seminara, Agnese and Michael P. Brenner and Weitz, David A}
}
@article {156336,
	title = {Drug dissolution chip (DDC): A microfluidic approach for drug release},
	journal = {Small},
	volume = {7},
	number = {21},
	year = {2011},
	pages = {3011-3015},
	abstract = {
	The first pharmaceutical dissolution testing device\&nbsp;for multiparticulate drug delivery systems on a microfluidic chip is presented. This versatile platform technology allows for simultaneous analysis of the drug concentration in the dissolution medium and of the solid parts of the sample immobilized in the device with different analytical techniques. By mimicking the fate of drug release in the human body, this can contribute to the optimization of therapeutic effectiveness during the development of novel drug release systems.

},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/smll.201100520},
	author = {Windbergs, Maike and Weitz, David A}
}
@inbook {156171,
	title = {Colloidal glasses},
	booktitle = {Glasses and Grains},
	volume = {61},
	year = {2011},
	pages = {25-39},
	abstract = {Classes and granular materials share many features in common: Both can flow under some conditions but form disordered solids under other conditions. The similarity is captured within the jamming phase diagram, which considers how the solid-like state is fluidized with decreasing density, increasing shear stress, and increasing agitation, due to temperature in the case of molecular glasses and to shaking or some other form of agitation in the case of granular materials. Colloidal particles also undergo both jamming and glass transitions. They have the advantage that they are thermalized by temperature and that the particles themselves are large enough to be directly visualized. Thus, the study of the glass transition in colloids can provide an interesting comparison between molecular glasses and granular materials. This paper reviews the properties of colloidal suspensions near the colloidal glass transition, and explores both the glass-like properties and the jamming properties of these materials.},
	url = {https://link.springer.com/chapter/10.1007/978-3-0348-0084-6_2$\#$citeas},
	author = {Weitz, David A}
}
@article {156096,
	title = {Controllable microfluidic production of multicomponent multiple emulsions},
	journal = {Lab on a Chip},
	volume = {11},
	number = {9},
	year = {2011},
	pages = {1587-1592},
	abstract = {A hierarchical and scalable microfluidic device constructed from a combination of three building blocks enables highly controlled generation of multicomponent multiple emulsions. The number, ratio and size of droplets, each with distinct contents being independently co-encapsulated in the same level, can be precisely controlled. The building blocks are a drop maker, a connector and a liquid extractor; combinations of these enable the scale-up of the device to create higher-order multicomponent multiple emulsions with exceptionally diverse structures. These multicomponent multiple emulsions offer a versatile and promising platform for precise encapsulation of incompatible actives or chemicals, for synergistic delivery and biochemical and chemical reactions, and for engineering multicompartment materials with controlled internal phases.},
	url = {https://pubs.rsc.org/en/content/articlelanding/2011/LC/c1lc20065h$\#$!divAbstract},
	author = {Wang, Wei and Xie, Rui and Ju, Xiao-Jie and Luo, Tao and Liu, Li and Weitz, David A and Chu, Liang-Yin}
}
@article {156076,
	title = {On-demand drug delivery from self-assembled nanofibrous gels: A new approach for treatment of proteolytic disease},
	journal = {Journal of Biomedical Materials Research Part A},
	volume = {97A},
	number = {2},
	year = {2011},
	pages = {103-110},
	abstract = {Local delivery of drugs offers the potential for high local drug concentration while minimizing systemic toxicity, which is often observed with oral dosing. However, local depots are typically administered less frequently and include an initial burst followed by a continuous release. To maximize efficiency of therapy, it is critical to ensure that drug is only released when needed. One of the hallmarks of rheumatoid arthritis, for example, is its variable disease activity consisting of exacerbations of inflammation punctuated by periods of remission. This presents significant challenges for matching localized drug delivery with disease activity. An optimal system would be nontoxic and only release drugs during the period of exacerbation, self-titrating in response to the level of inflammation. We report the development of an injectable self-assembled nanofibrous hydrogel, from a generally recognized as safe material, which is capable of encapsulation and release of agents in response to specific enzymes that are significantly upregulated in a diseased state including matrix metalloproteinases (MMP-2 and MMP-9) and esterases. We show that these self-assembled nanofibrous gels can withstand shear forces that may be experienced in dynamic environments such as joints, can remain stable following injection into healthy joints of mice, and can disassemble in vitro to release encapsulated agents in response to synovial fluid from arthritic patients. This novel approach represents a next-generation therapeutic strategy for localized treatment of proteolytic diseases. (C) 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 97A: 103-110, 2011.},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/jbm.a.33020},
	author = {Vemula, Praveen Kumar and Boilard, Eric and Syed, Abdullah and Campbell, Nathaniel R. and Muluneh, Melaku and Weitz, David A and Lee, David M. and Karp, Jeffrey M}
}
@article {155931,
	title = {Collective cell guidance by cooperative intercellular forces},
	journal = {Nature Materials},
	volume = {10},
	year = {2011},
	pages = {469-475},
	abstract = {Cells comprising a tissue migrate as part of a collective. How collective processes are coordinated over large multi-cellular assemblies has remained unclear, however, because mechanical stresses exerted at cell-cell junctions have not been accessible experimentally. We report here maps of these stresses within and between cells comprising a monolayer. Within the cell sheet there arise unanticipated fluctuations of mechanical stress that are severe, emerge spontaneously, and ripple across the monolayer. Within that stress landscape, local cellular migrations follow local orientations of maximal principal stress. Migrations of both endothelial and epithelial monolayers conform to this behaviour, as do breast cancer cell lines before but not after the epithelial-mesenchymal transition. Collective migration in these diverse systems is seen to be governed by a simple but unifying physiological principle: neighbouring cells join forces to transmit appreciable normal stress across the cell-cell junction, but migrate along orientations of minimal intercellular shear stress.},
	url = {https://www.nature.com/articles/nmat3025},
	author = {Tambe, Dhananjay T. and Hardin, C. Corey and Angelini, Thomas E. and Rajendran, Kavitha and Park, Chan Young and Serra-Picamal, Xavier and Zhou, Enhua H. and Zaman, Muhammad H. and James P. Butler and Weitz, David A and Jeffrey J. Fredberg and Trepat, Xavier}
}
@article {155961,
	title = {Early development drug formulation on a chip: Fabrication of nanoparticles using a microfluidic spray dryer},
	journal = {Lab on a Chip},
	volume = {11},
	number = {14},
	year = {2011},
	pages = {2362-2368},
	abstract = {Early development drug formulation is exacerbated by increasingly poor bioavailability of potential candidates. Prevention of attrition due to formulation problems necessitates physicochemical analysis and formulation studies at a very early stage during development, where the availability of a new substance is limited to small quantities, thus impeding extensive experiments. Miniaturization of common formulation processes is a strategy to overcome those limitations. We present a versatile technique for fabricating drug nanoformulations using a microfluidic spray dryer. Nanoparticles are formed by evaporative precipitation of the drug-loaded spray in air at room temperature. Using danazol as a model drug, amorphous nanoparticles of 20-60 nm in diameter are prepared with a narrow size distribution. We design the device with a geometry that allows the injection of two separate solvent streams, thus enabling co-spray drying of two substances for the production of drug co-precipitates with tailor-made composition for optimization of therapeutic efficiency.},
	url = {https://pubs.rsc.org/en/content/articlelanding/2011/LC/c1lc20298g$\#$!divAbstract},
	author = {Thiele, Julian and Windbergs, Maike and Abate, Adam R. and Trebbin, Martin and Shum, Ho Cheung and Foerster, Stephan and Weitz, David A}
}
@article {155876,
	title = {Cocktail physics},
	journal = {Physics World},
	volume = {24},
	year = {2011},
	pages = {25-28},
	abstract = {
	Many top chefs are well known for taking a more scientific approach to cooking in recent years, and some {\textquotedblleft}mixologists{\textquotedblright} are now extending the same philosophy to cocktails. Naveen N. Sinha and David A. Weitz explain the theory and techniques behind these increasingly exotic mixed drinks.

},
	url = {https://physicsworld.com/a/cocktail-physics/},
	author = {Sinha, Naveen N. and Weitz, David A}
}
@article {155916,
	title = {Hierarchical porous materials made by drying complex suspensions},
	journal = {Langmuir},
	volume = {27},
	number = {3},
	year = {2011},
	pages = {955-964},
	abstract = {Porous structures containing pores at different length scales are often encountered in nature and are important in many applications. While several processing routes have been demonstrated to create such hierarchical porous materials, most methods either require chemical gelation reactions or do not allow for the desired control of pore sizes over multiple length scales. We describe a versatile and simple approach to produce tailor-made hierarchical porous materials that relies solely on the process of drying. Our results show that simple drying of a complex suspension can lead to the self-assembly of droplets, colloidal particles and molecular species into unique 3D hierarchical porous structures. Using a microfluidic device to produce monodisperse templating droplets of tunable size, we prepared materials with up to three levels of hierarchy exhibiting monodisperse pores ranging from 10 nm to 800 mu m. While the size of macropores obtained after drying is determined by the size of initial droplets, the interconnectivity between macropores is strongly affected by the type of droplet stabilizer (surfactants or particles). This simple route can be used to prepare porous materials of many chemical compositions and has great potential for creating artificial porous structures that capture some of the exquisite hierarchical features of porous biological materials.},
	url = {https://pubs.acs.org/doi/10.1021/la103995g},
	author = {Studart, Andre R. and Studer, Julia and Xu, Lei and Yoon, Kisun and Shum, Ho Cheung and Weitz, David A}
}
@article {155901,
	title = {Hyperbranched polyglycerols on the nanometer and micrometer scale},
	journal = {Biomaterials},
	volume = {32},
	number = {5},
	year = {2011},
	pages = {1311-1316},
	abstract = {We report the preparation of polyglycerol particles on different length scales by extending the size of hyperbranched polyglycerols (3 nm) to nanogels (32 nm) and microgels (140 and 220 mu m). We use miniemulsion templating for the preparation of nanogels and microfluidic templating for the preparation of microgels, which we obtain through a free-radical polymerization of hyperbranched polyglycerol decaacrylate and polyethylene glycol-diacrylate. The use of mild polymerization conditions allows yeast cells to be encapsulated into the resultant microgels with cell viabilities of approximately 30\%. (C) 2010 Elsevier Ltd. All rights reserved.},
	url = {https://www.sciencedirect.com/science/article/abs/pii/S0142961210012986?via\%3Dihub},
	author = {Steinhilber, Dirk and Seiffert, Sebastian and Heyman, John A. and Paulus, Florian and Weitz, David A and Haag, Rainer}
}
@article {155881,
	title = {Stress enhancement in the delayed yielding of colloidal gels},
	journal = {Physical Review Letters},
	volume = {106},
	number = {24},
	year = {2011},
	pages = {248303},
	abstract = {Networks of aggregated colloidal particles are solidlike and can sustain an applied shear stress while exhibiting little or no creep; however, ultimately they will catastrophically fail. We show that the time delay for this yielding decreases in two distinct exponential regimes with applied stress. This behavior is universal and found for a variety of colloidal gel systems. We present a bond-rupture model that quantitatively describes this behavior and highlights the role of mesoscopic structures. Our result gives new insight into the nature of yielding in these soft solid materials.},
	url = {https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.106.248303},
	author = {Sprakel, Joris and Lindstroem, Stefan B. and Kodger, Thomas E. and Weitz, David A}
}
@article {155846,
	title = {Dewetting-induced membrane formation by adhesion of amphiphile-laden interfaces},
	journal = {Journal of the American Chemical Society},
	volume = {133},
	number = {12},
	year = {2011},
	pages = {4420-4426},
	abstract = {We introduce an approach for forming bilayer polymer membranes by adhesion of amphiphile-laden interfaces. This adhesion is induced by a reduction of solvent quality for the amphiphilic diblock copolymers through selective evaporation of good solvent in the solvent mixture. By combining this membrane formation mechanism with a double-emulsion-templated approach for vesicle formation, we fabricate monodisperse polymersomes that exhibit excellent membrane uniformity, and structural stability, using a method that has high encapsulation efficiency. Moreover, we also show that the technique is versatile and can be applied to different block copolymers. The ability to direct the assembly of amphiphiles into a membrane creates new opportunities to engineer the structures of vesicles on the level of the individual bilayer leaflets.},
	url = {https://pubs.acs.org/doi/10.1021/ja108673h},
	author = {Shum, Ho Cheung and Santanach-Carreras, Enric and Kim, Jin-Woong and Ehrlicher, Allen and Bibette, Jerome and Weitz, David A}
}
@article {155866,
	title = {Multicompartment polymersomes from double emulsions},
	journal = {Angewandte Chemie-International Edition},
	volume = {50},
	number = {7},
	year = {2011},
	pages = {1648-1651},
	abstract = {
	Versatile chambers: A microfluidic technique is used to generate polymersomes with multiple compartments using double emulsions with different morphology as templates (see scheme). The polymersomes could be utilized for encapsulation of multiple substances and as reaction vessels that enable triggered reaction with controlled stoichometry of the reactants.

},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/anie.201006023},
	author = {Shum, Ho Cheung and Zhao, Yuan-jin and Kim, Shin-Hyun and Weitz, David A}
}
@article {155756,
	title = {Reduced UV light scattering in PDMS microfluidic devices},
	journal = {Lab on a Chip},
	volume = {11},
	number = {5},
	year = {2011},
	pages = {966-968},
	abstract = {Microfluidic devices which consist of polydimethylsiloxane ( PDMS) are used extensively for the production of polymer microparticles through the use of droplet templating and on-chip photopolymerization. However, in existing methods, spatial confinement of the photochemical droplet solidification is impaired by UV light scattering inside the PDMS elastomer. We present a technique to load PDMS microfluidic devices with a fluorescent dye that absorbs the scattered UV light and shifts it to longer wavelengths. By this means, the stray light is no longer harmful, and UV exposure can be limited to a desired region on the microfluidic chip.},
	url = {https://pubs.rsc.org/en/content/articlelanding/2011/LC/c0lc00594k$\#$!divAbstract},
	author = {Seiffert, Sebastian and Dubbert, Janine and Richtering, Walter and Weitz, David A}
}
@article {155361,
	title = {Direct visualization of pH-dependent evolution of structure and dynamics in microgel suspensions},
	journal = {Journal of Physics-Condensed Matter},
	volume = {23},
	year = {2011},
	pages = {505101},
	abstract = {We use 3D confocal microscopy combined with image analysis and particle tracking techniques to study the structure and dynamics of aqueous suspensions of fluorescently labelled p(NIPAm-co-AAc) microgel particles. By adjusting the pH we can tune the interactions between the microgel particles from purely repulsive near neutral pH, to weakly attractive at low pH. This change in the interaction potential has a pronounced effect on the manner in which the suspensions solidify. We directly follow the evolution of the system after a quench from the liquid state to obtain detailed information on the route to kinetic arrest. At low pH and low concentration, dynamic arrest results mainly from crystallization driven by the attraction between particles; crystal nucleation occurs homogeneously throughout the sample and does not appear to be localized to geometric boundaries. Moreover, the growth of crystals is characterized by nucleation-limited kinetics where a rapid growth of crystal domains takes place after a long concentration-dependent lag time. At low pH and high concentration, relaxation of the suspension is constrained and it evolves only slightly, resulting in a disordered solid. At neutral pH, the dynamics are a function of the particle number concentration only; a high concentration leads to the formation of a disordered soft glassy solid.},
	url = {https://iopscience.iop.org/article/10.1088/0953-8984/23/50/505101},
	author = {Muluneh, M. and Sprakel, J. and Wyss, H. M. and Mattsson, J. and Weitz, D. A.}
}
@article {155251,
	title = {Controlling droplet incubation using close-packed plug flow},
	journal = {Biomicrofluidics},
	volume = {5},
	number = {2},
	year = {2011},
	pages = {024101},
	abstract = {Controlling droplet incubation is critical for droplet-based microfluidic applications; however, current techniques are either of limited precision or place strict limits on the incubation times that can be achieved. Here, we present a simple technique to control incubation time by exploiting close-packed plug flow. In contrast to other techniques, this technique is applicable to very short and very long incubation times. (C) 2011 American Institute of Physics. [doi:10.1063/1.3576934]},
	url = {https://aip.scitation.org/doi/10.1063/1.3576934},
	author = {Mary, Pascaline and Abate, Adam R. and Agresti, Jeremy J. and Weitz, David A}
}
@article {155256,
	title = {On-chip background noise reduction for cell-based assays in droplets},
	journal = {Lab on a Chip},
	volume = {11},
	number = {12},
	year = {2011},
	pages = {2066-2070},
	abstract = {Droplet-based microfluidics provides an excellent platform for high-throughput biological assays. Each droplet serves as a reaction vessel with a volume as small as a few picolitres. This is an important technology for a high variety of applications. However this technology is restricted to homogeneous assays as it is very difficult to wash reagents from the reaction vessel. To help overcome this limitation, we introduce a method to effectively dilute the content of a droplet while retaining the high throughput. We use electrocoalescence to merge the parent drop with a much larger drop containing only solvent, thereby increasing the volume of the drop by as much as a factor of 14. Three T-junctions then break the larger drop into eight smaller droplets. This dilution and break-up process can be repeated, thus leading to many drops comparable in size to the original one but with much lower concentration of reagents. The system is fully integrated in a PDMS device. To demonstrate its power, we perform a labelling reaction at the surface of the cells by coencapsulating yeast cells expressing S6 peptide tags with the enzyme SFP synthase and the fluorescent substrate CoA 488. After reaction, the droplets are diluted twice using the system and the intensity of their fluorescence is measured. This noise reduction method enables us to more easily distinguish the fluorescence at the surface of a single cell from the fluorescent background inside the droplet.},
	url = {https://pubs.rsc.org/en/content/articlelanding/2011/LC/c1lc20159j$\#$!divAbstract},
	author = {Mary, Pascaline and Chen, Angela and Chen, Irwin and Abate, Adam R. and Weitz, David A}
}
@article {155086,
	title = {Control of non-linear elasticity in F-actin networks with microtubules},
	journal = {Soft Matter},
	volume = {7},
	number = {3},
	year = {2011},
	pages = {902-906},
	abstract = {We measure the elastic properties of composite cytoskeletal networks consisting of cross-linked actin filaments and microtubules. We show that even a small concentration of microtubules leads to dramatic and qualitative changes in the non-linear elastic properties of the actin filament networks. Specifically, we find that microtubules promote non-linear stiffening of F-actin networks because they are much stiffer than actin filaments and therefore suppress non-uniform strain. This finding may be relevant for interpretation of the mechanical behavior of cells, while also suggesting a new way to reinforce the non-linear elasticity of semiflexible polymer materials.},
	url = {https://pubs.rsc.org/en/content/articlelanding/2011/SM/C0SM00478B$\#$!divAbstract},
	author = {Lin, Yi-Chia and Koenderink, Gijsje H and MacKintosh, Frederick C and Weitz, David A}
}
@article {154961,
	title = {Highly monodisperse conjugated polymer particles synthesized with drop-based microfluidics},
	journal = {Chemical Communications},
	volume = {47},
	number = {45},
	year = {2011},
	pages = {12379-12381},
	abstract = {A facile method for preparing highly monodisperse, sub-micrometre conjugated polymer particles is reported. The particles are prepared through emulsification of a conjugated polymer solution on a microfluidic chip followed by solvent evaporation. The particle size is tuned between 150 nm to 2 mu m, by controlling the polymer concentration.},
	url = {https://pubs.rsc.org/en/content/articlelanding/2011/CC/c1cc14251h$\#$!divAbstract},
	author = {Kuehne, Alexander J. C. and Weitz, David A}
}
@article {154956,
	title = {A switchable digital microfluidic droplet dye-laser},
	journal = {Lab on a Chip},
	volume = {11},
	number = {21},
	year = {2011},
	pages = {3716-3719},
	abstract = {Digital microfluidic devices allow the manipulation of droplets between two parallel electrodes. These electrodes can act as mirrors generating a micro-cavity, which can be exploited for a droplet dye-laser. Three representative laser-dyes with emission wavelengths spanning the whole visible spectrum are chosen to show the applicability of this concept. Sub-microlitre droplets of laser-dye solution are moved in and out of a lasing site on-chip to down-convert the UV-excitation light into blue, green and red laser-pulses.},
	url = {https://pubs.rsc.org/en/content/articlelanding/2011/LC/c1lc20405j$\#$!divAbstract},
	author = {Kuehne, Alexander J. C. and Gather, Malte C. and Eydelnant, Irwin A. and Yun, Seok-Hyun and Weitz, David A and Aaron R. Wheeler}
}
@article {154886,
	title = {Multiple polymersomes for programmed release of multiple components},
	journal = {Journal of the American Chemical Society},
	volume = {133},
	number = {38},
	year = {2011},
	pages = {15165-15171},
	abstract = {Long-term storage and controlled release of multiple components while avoiding cross-contamination have potentially important applications for pharmaceuticals and cosmetics. Polymersomes are very promising delivery vehicles but cannot be used to encapsulate multiple independent components and release them in a controlled manner. Here, we report a microfluidic approach to produce multiple polymersomes, or polymersomes-in-polymersome by design, enabling encapsulation and programmed release of multiple components. Monodisperse polymersomes are prepared from templates of double-emulsion drops, which in turn are injected as the innermost phase to form the second level of double-emulsion drops, producing double polymersomes. Using the same strategy, higher-order polymersomes are also prepared. In addition, incorporation of hydrophobic homopolymer into the different bilayers of the multiple polymersomes enables controlled and sequential dissociation of the different bilayer membranes in a programmed fashion. The high encapsulation efficiency of this microfluidic approach, as well as its programmability and the biocompatibility of the materials used to form the polymersomes, will provide new opportunities for practical delivery systems of multiple components.},
	url = {https://pubs.acs.org/doi/10.1021/ja205687k},
	author = {Kim, Shin-Hyun and Shum, Ho Cheung and Kim, Jin Woong and Cho, Jun-Cheol and Weitz, David A}
}
@article {154901,
	title = {Observation of spatial propagation of amyloid assembly from single nuclei},
	journal = {Proceedings of the National Academy of Sciences of the United States of America},
	volume = {108},
	number = {36},
	year = {2011},
	pages = {14746-14751},
	abstract = {The crucial early stages of amyloid growth, in which normally soluble proteins are converted into fibrillar nanostructures, are challenging to study using conventional techniques yet are critical to the protein aggregation phenomena implicated in many common pathologies. As with all nucleation and growth phenomena, it is difficult to track individual nuclei in traditional macroscopic experiments, which probe the overall temporal evolution of the sample, but do not yield detailed information on the primary nucleation step as they mix independent stochastic events into an ensemble measurement. To overcome this limitation, we have developed microdroplet assays enabling us to detect single primary nucleation events and to monitor their subsequent spatial as well as temporal evolution, both of which we find to be determined by secondary nucleation phenomena. By deforming the droplets to high aspect ratio, we visualize in real-time propagating waves of protein assembly emanating from discrete primary nucleation sites. We show that, in contrast to classical gelation phenomena, the primary nucleation step is characterized by a striking dependence on system size, and the filamentous protein self-assembly process involves a highly nonuniform spatial distribution of aggregates. These findings deviate markedly from the current picture of amyloid growth and uncover a general driving force, originating from confinement, which, together with biological quality control mechanisms, helps proteins remain soluble and therefore functional in nature.},
	url = {https://www.pnas.org/content/108/36/14746},
	author = {Knowles, Tuomas P. J. and White, Duncan A. and Abate, Adam R. and Agresti, Jeremy J. and Cohen, Samuel I. A. and Sperling, Ralph A. and De Genst, Erwin J. and Dobson, Christopher M and Weitz, David A}
}
@article {154891,
	title = {One-step emulsification of multiple concentric shells with capillary microfluidic devices},
	journal = {Angewandte Chemie-International Edition},
	volume = {50},
	number = {37},
	year = {2011},
	pages = {8731-8734},
	abstract = {
	Polymeric onions: A facile method to produce monodisperse multiple emulsion drops of high order is developed using a capillary microfluidic device. Coaxial multiphase flows are stabilized by confinement in microcapillary and emulsified to multiple emulsion drops. The breakup of coaxial interfaces, triggered by the core-drop, facilitates the making of multiple emulsion drops of onionlike configuration.



	\&nbsp;

},
	url = {https://onlinelibrary.wiley.com/doi/10.1002/anie.201102946},
	author = {Kim, Shin-Hyun and Weitz, David A}
}
@article {154861,
	title = {Amphiphilic crescent-moon-shaped microparticles formed by selective adsorption of colloids},
	journal = {Journal of the American Chemical Society},
	volume = {133},
	number = {14},
	year = {2011},
	pages = {5516-5524},
	abstract = {We use a microfluidic device to prepare monodisperse amphiphilic particles in the shape of a crescent-moon and use these particles to stabilize oil droplets in water. The microfluidic device is comprised of a tapered capillary in a theta (theta) shape that injects two oil phases into water in a single receiving capillary. One oil is a fluorocarbon, while the second is a photocurable monomer, which partially wets the first oil drop; silica colloids in the monomer migrate and adsorb to the interface with water but do not protrude into the oil interface. Upon UV-induced polymerization, solid particles with the shape of a crescent moon are formed; removal of fluorocarbon oil yields amphiphilic particles due to the selective adsorption of silica colloids. The resultant amphiphilic microparticles can be used to stabilize oil drops in a mixture of water and ethanol; if they are packed to sufficient surface density on the interface of the oil drop, they become immobilized, preventing direct contact between neighboring drops, thereby providing the stability.},
	url = {https://pubs.acs.org/doi/10.1021/ja200139w},
	author = {Kim, Shin-Hyun and Abbaspourrad, Alireza and Weitz, David A}
}
@article {154866,
	title = {Double-emulsion drops with ultra-thin shells for capsule templates},
	journal = {Lab on a Chip},
	volume = {11},
	number = {18},
	year = {2011},
	pages = {3162-3166},
	abstract = {We introduce an emulsification technique that creates monodisperse double-emulsion drops with a core-shell geometry having an ultra-thin wall as a middle layer. We create a biphasic flow in a microfluidic capillary device by forming a sheath flow consisting of a thin layer of a fluid with high affinity to the capillary wall flowing along the inner wall of the capillary, surrounding the innermost fluid. This creates double-emulsion drops, using a single-step emulsification, having a very thin fluid shell. If the shell is solidified, its thickness can be small as a hundred nanometres or even less. Despite the small thickness of this shell, these structures are nevertheless very stable, giving them great potential for encapsulation. We demonstrate this by creating biodegradable microcapsules of poly(lactic acid) with a shell thickness of a few tens of nanometres, which are potentially useful for encapsulation and delivery of drugs, cosmetics, and nutrients.},
	url = {https://pubs.rsc.org/en/content/articlelanding/2011/LC/C1LC20434C$\#$!divAbstract},
	author = {Kim, Shin-Hyun and Kim, Jin Woong and Cho, Jun-Cheol and Weitz, David A}
}
@article {154396,
	title = {Mechanical strain in actin networks regulates FilGAP and integrin binding to filamin A},
	journal = {Nature},
	volume = {478},
	year = {2011},
	pages = {260-U154},
	abstract = {Mechanical stresses elicit cellular reactions mediated by chemical signals. Defective responses to forces underlie human medical disorders(1-4) such as cardiac failure(5) and pulmonary injury(6). The actin cytoskeleton{\textquoteright}s connectivity enables it to transmit forces rapidly over large distances(7), implicating it in these physiological and pathological responses. Despite detailed knowledge of the cytoskeletal structure, the specific molecular switches that convert mechanical stimuli into chemical signals have remained elusive. Here we identify the actin-binding protein filamin A (FLNA)(8,9) as a central mechanotransduction element of the cytoskeleton. We reconstituted a minimal system consisting of actin filaments, FLNA and two FLNA-binding partners: the cytoplasmic tail of beta-integrin, and FilGAP. Integrins form an essential mechanical linkage between extracellular and intracellular environments, with beta-integrin tails connecting to the actin cytoskeleton by binding directly to filamin(4). FilGAP is an FLNA-binding GTPase-activating protein specific for RAC, which in vivo regulates cell spreading and bleb formation(10). Using fluorescence loss after photoconversion, a novel, high-speed alternative to fluorescence recovery after photobleaching(11), we demonstrate that both externally imposed bulk shear and myosin-II-driven forces differentially regulate the binding of these partners to FLNA. Consistent with structural predictions, strain increases beta-integrin binding to FLNA, whereas it causes FilGAP to dissociate from FLNA, providing a direct and specific molecular basis for cellular mechanotransduction. These results identify a molecular mechanotransduction element within the actin cytoskeleton, revealing that mechanical strain of key proteins regulates the binding of signalling molecules.},
	url = {https://www.nature.com/articles/nature10430},
	author = {Ehrlicher, A. J. and Nakamura, F. and Hartwig, J. H. and Weitz, D. A. and Stossel, T. P.}
}
@article {154261,
	title = {Rheology of attractive emulsions},
	journal = {Physical Review E},
	volume = {84},
	year = {2011},
	pages = {041404},
	abstract = {We show how attractive interactions dramatically influence emulsion rheology. Unlike the repulsive case, attractive emulsions below random close packing, phi(RCP), can form soft gel-like elastic solids. However, above phi(RCP), attractive and repulsive emulsions have similar elasticities. Such compressed attractive emulsions undergo an additional shear-driven relaxation process during yielding. Our results suggest that attractive emulsions begin to yield at weak points through the breakage of bonds, and, above phi(RCP), also undergo droplet configurational rearrangements.},
	url = {https://journals.aps.org/pre/abstract/10.1103/PhysRevE.84.041404},
	author = {Datta, Sujit S. and Gerrard, Dustin D. and Rhodes, Travers S. and Mason, Thomas G. and Weitz, David A}
}
@article {154171,
	title = {Microfluidic fabrication of complex-shaped microfibers by liquid template-aided multiphase microflow},
	journal = {Lab on a Chip},
	volume = {11},
	number = {8},
	year = {2011},
	pages = {1477-1483},
	abstract = {This study presents a simple microfluidic approach to the rapid fabrication of complex-shaped microfibers (e.g., single hollow, double hollow, and microbelt), with highly uniform structures, based on a combination of the spontaneous formation of polymeric jet streams and in situ photopolymerization. Two laminar flows of a photocurable fluid and a liquid template (nonpolymerizing fluid) spontaneously form jet streams in equilibrium states in microfluidic channels because of the minimization of the interfacial energy between the two fluids. The formation of the jet streams strongly depends on the spreading coefficients and the evolution time along the downstream of the microfluidic system. Thus, the simple control of the spreading coefficients can guide microfibers into various shapes. The sizes of the core and shell of the hollow fibers can also be readily manipulated by the flow rates of the polymerizing fluid and the liquid template phase. Asymmetric hollow fibers can also be produced in different evolutionary states in the microfluidic system. The microfluidic approach shown here represents a significant step toward the easy fabrication of microfibers with readily controllable structures and geometries. We anticipate that this novel fabrication approach and the prediction method based on spreading coefficients presented in this work can be applied to produce a wide variety of functional microfibrous materials.},
	url = {https://pubs.rsc.org/en/content/articlelanding/2011/LC/c0lc00711k$\#$!divAbstract},
	author = {Choi, Chang-Hyung and Yi, Hyunmin and Hwang, Sora and Weitz, David A and Lee, Chang-Soo}
}
@article {154121,
	title = {Breakup of double emulsions in constrictions},
	journal = {Soft Matter},
	volume = {7},
	number = {6},
	year = {2011},
	pages = {2345-2347},
	abstract = {We report the controlled breakup of double emulsion droplets as they flow through an orifice of a tapered nozzle. The results are summarized in a phase diagram in terms of the droplet-to-orifice diameter ratio and the capillary number. We identify a flow regime where the inner aqueous phase is released.},
	url = {https://pubs.rsc.org/en/content/articlelanding/2011/SM/c0sm01100b$\#$!divAbstract},
	author = {Chen, Haosheng and Li, Jiang and Shum, Ho Cheung and Stone, Howard A. and Weitz, David A}
}
@article {154131,
	title = {Reactions in double emulsions by flow-controlled coalescence of encapsulated drops},
	journal = {Lab on a Chip},
	volume = {11},
	number = {14},
	year = {2011},
	pages = {2312-2315},
	abstract = {We demonstrate a microfluidic method to first generate double emulsion droplets containing two different inner drops, and to then control the internal coalescence of the encapsulated drops. The advantages of the core-coalescence method are illustrated by fabricating high viscosity particles and by demonstrating the dissolution of cell membranes.},
	url = {https://pubs.rsc.org/en/content/articlelanding/2011/LC/c1lc20265k$\#$!divAbstract},
	author = {Chen, Haosheng and Zhao, Yuanjin and Li, Jiang and Guo, Ming and Wan, Jiandi and Weitz, David A and Stone, Howard A.}
}
@article {153971,
	title = {Glass-like dynamics of collective cell migration},
	journal = {Proceedings of the National Academy of Sciences of the United States of America},
	volume = {108},
	number = {12},
	year = {2011},
	pages = {4714-4719},
	abstract = {Collective cell migration in tissues occurs throughout embryonic development, during wound healing, and in cancerous tumor invasion, yet most detailed knowledge of cell migration comes from single-cell studies. As single cells migrate, the shape of the cell body fluctuates dramatically through cyclic processes of extension, adhesion, and retraction, accompanied by erratic changes in migration direction. Within confluent cell layers, such subcellular motions must be coupled between neighbors, yet the influence of these subcellular motions on collective migration is not known. Here we study motion within a confluent epithelial cell sheet, simultaneously measuring collective migration and subcellular motions, covering a broad range of length scales, time scales, and cell densities. At large length scales and time scales collective migration slows as cell density rises, yet the fastest cells move in large, multicell groups whose scale grows with increasing cell density. This behavior has an intriguing analogy to dynamic heterogeneities found in particulate systems as they become more crowded and approach a glass transition. In addition we find a diminishing self-diffusivity of short-wavelength motions within the cell layer, and growing peaks in the vibrational density of states associated with cooperative cell-shape fluctuations. Both of these observations are also intriguingly reminiscent of a glass transition. Thus, these results provide a broad and suggestive analogy between cell motion within a confluent layer and the dynamics of supercooled colloidal and molecular fluids approaching a glass transition.},
	url = {https://www.pnas.org/content/108/12/4714},
	author = {Angelini, Thomas E. and Hannezo, Edouard and Trepat, Xavier and Marquez, Manuel and Jeffrey J. Fredberg and Weitz, David A}
}
@article {153896,
	title = {Air-bubble-triggered drop formation in microfluidics},
	journal = {Lab on a Chip},
	volume = {11},
	number = {10},
	year = {2011},
	pages = {1713-1716},
	abstract = {In microfluidic devices, droplets are normally formed using T-junction or flow focus mechanisms. While both afford a high degree of control over drop formation, they are limited in maximum production rate by the jetting transition. Here, we introduce a new drop formation mechanism that is not limited by jetting, allowing much faster drop production.},
	url = {https://pubs.rsc.org/en/content/articlelanding/2011/LC/c1lc20108e$\#$!divAbstract},
	author = {Abate, Adam R. and Weitz, David A}
}
@article {153871,
	title = {Efficient encapsulation with plug-triggered drop formation},
	journal = {Physical Review E},
	volume = {84},
	year = {2011},
	pages = {031502},
	abstract = {Monodisperse microscale drops formed with microfluidic devices are useful for encapsulating cells, microgel particles, or even additional drops. These techniques are thus useful for applications ranging from high-throughput biology to monodisperse particle and capsule synthesis, which require encapsulation of such objects. However, it is challenging to efficiently encapsulate the objects in all drops; often, the objects are encapsulated inefficiently, resulting in many improperly filled, unusable drops. Here, we describe a phenomenon that allows very efficient encapsulation. We use the inflow of the object to plug the drop maker nozzle; the continued injection of the outer phase pinches off a drop, thereby encapsulating the object; this yields precisely one object encapsulated per drop.},
	url = {https://journals.aps.org/pre/abstract/10.1103/PhysRevE.84.031502},
	author = {Abate, Adam R. and Rotem, Assaf and Thiele, Julian and Weitz, David A}
}
@article {153901,
	title = {Faster multiple emulsification with drop splitting},
	journal = {Lab on a Chip},
	volume = {11},
	number = {11},
	year = {2011},
	pages = {1911-1915},
	abstract = {Microfluidic devices can form emulsions in which the drops have an intricate, controlled structure; however, a challenge is that the droplets are produced slowly, typically only a few millilitres per hour. Here, we present a simple technique to increase the production rate. Using a large drop maker, we produce large drops at a fast volumetric rate; by splitting these drops several times in a splitting array, we create drops of the desired small size. The advantage of this over forming the small drops directly using a small drop maker is that the drops can be formed at much faster rates. This can be applied to the production of single and multiple emulsions.},
	url = {https://pubs.rsc.org/en/content/articlelanding/2011/LC/c0lc00706d$\#$!divAbstract},
	author = {Abate, Adam R. and Weitz, David A}
}
@article {153881,
	title = {One-step formation of multiple emulsions in microfluidics},
	journal = {Lab on a Chip},
	volume = {11},
	number = {2},
	year = {2011},
	pages = {253-258},
	abstract = {We present a robust way to create multiple emulsions with controllable shell thicknesses that can vary over a wide range. We use a microfluidic device to create a coaxial jet of immiscible fluids; using a dripping instability, we break the jet into multiple emulsions. By controlling the thickness of each layer of the jet, we adjust the thicknesses of the shells of the multiple emulsions. The same method is also effective in creating monodisperse emulsions from fluids that cannot otherwise be controllably emulsified, such as, for example, viscoelastic fluids.},
	url = {https://pubs.rsc.org/en/content/articlelanding/2011/LC/C0LC00236D$\#$!divAbstract},
	author = {Abate, Adam R. and Thiele, Julian and Weitz, David A}
}
@article {153906,
	title = {Syringe-vacuum microfluidics: A portable technique to create monodisperse emulsions},
	journal = {Biomicrofluidics},
	volume = {5},
	number = {1},
	year = {2011},
	pages = {014107},
	abstract = {We present a simple method for creating monodisperse emulsions with microfluidic devices. Unlike conventional approaches that require bulky pumps, control computers, and expertise with device physics to operate devices, our method requires only the microfluidic device and a hand-operated syringe. The fluids needed for the emulsion are loaded into the device inlets, while the syringe is used to create a vacuum at the device outlet; this sucks the fluids through the channels, generating the drops. By controlling the hydrodynamic resistances of the channels using hydrodynamic resistors and valves, we are able to control the properties of the drops. This provides a simple and highly portable method for creating monodisperse emulsions. (C) 2011 American Institute of Physics. [doi: 10.1063/1.3567093]},
	url = {https://aip.scitation.org/doi/10.1063/1.3567093},
	author = {Abate, Adam R. and Weitz, David A}
}
@article {153846,
	title = {Synthesis of monodisperse microparticles from non-Newtonian polymer solutions with microfluidic devices},
	journal = {Advanced Materials},
	volume = {23},
	number = {15},
	year = {2011},
	pages = {1757-1760},
	abstract = {Polymer solutions are useful precursors to synthesize microparticles with microfluidic devices, but most polymer solutions are incompatible with microfluidic emulsification due to their non-Newtonian flow characteristics. A technique is presented to form monodisperse particles from such solutions by surrounding them with a chaperoning Newtonian fluid and forcing both to pinch into preparticle drops.},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/adma.201004275},
	author = {Abate, Adam R. and Kutsovsky, Mikhail and Seiffert, Sebastian and Windbergs, Maike and Pinto, Luis F. V. and Rotem, Assaf and Utada, Andrew S. and Weitz, David A}
}
@article {155861,
	title = {Multicompartment polymersome gel for encapsulation},
	journal = {Soft Matter},
	volume = {7},
	number = {19},
	year = {2011},
	pages = {8762-8765},
	abstract = {
	We introduce an approach that combines the concepts of emulsion-templating and dewetting for fabricating polymersomes with a large number of compartments. The resultant polymersome gel behaves as a gel-like solid, but is a true vesicle suspended in an aqueous environment. Due to the thin membranes that separate the compartments, the polymersome gels have a high volume fraction of internal phase for encapsulation of hydrophilic actives; they also provide a large surface area of diblock copolymer membrane for encapsulation of lipophilic actives. Multiple actives can also be encapsulated in the gel without cross-contamination. Our technique represents a simple and versatile bulk approach for fabricating polymersome gels; it does not require the use of any specialized equipment or subsequent polymerization steps to solidify the gel. The resultant polymersome gel is promising as an encapsulating structure as well as a scaffold for tissue engineering.

},
	url = {https://pubs.rsc.org/en/content/articlelanding/2011/SM/c1sm06026k$\#$!divAbstract},
	author = {Shum, Ho Cheung and Weitz, David A}
}
@article {155711,
	title = {Novel surface acoustic wave (SAW)-driven closed PDMS flow chamber},
	journal = {Microfluidics and Nanofluidics},
	volume = {12},
	year = {2011},
	pages = {229-235},
	abstract = {
	In this article, we demonstrate a novel microfluidic flow chamber driven by surface acoustic waves. Our device is a closed loop channel with an integrated acoustic micropump without external fluidic connections that allows for the investigation of small fluid samples in a continuous flow. The fabrication of the channels is particularly simple and uses standard milling and PDMS molding. The micropump consists of gold electrodes deposited on a piezoelectric substrate employing photolithography. We show that the pump generates a pressure-driven Poiseuille flow, investigate the acoustic actuation mechanism, characterize the flow profile for different channel geometries, and evaluate the driving pressure, efficiency and response time of the acoustic micropump. The fast response time of our pump permits the generation of non-stationary flows. To demonstrate the versatility of the device, we have pumped a red blood cell suspension at a physiological rate of 60 beats/min.

},
	url = {https://link.springer.com/article/10.1007\%2Fs10404-011-0867-5},
	author = {Schmid, Lothar and Wixforth, Achim and Weitz, David A and Franke, Thomas}
}
