Microfluidics for material production:

We develop methods to create new functional materials using microfluidic devices. These devices provide capabilities for very precisely mixing fluids to form new materials. All the structures are based on drops which can both encapsulate active materials and serve as templates on which to build new structures. These have interesting properties and great technological potential for encapsulation and controlled release of a wide variety of active materials. We also consider methods to scale up the fabrication of these materials to produce practical quantities. This work is motivated by both fundamental studies and the potential for creating technologically valuable materials, and some of the work has led to industrial applications.

Fabrication of responsive microcapsules: Capsules, which respond to stimuli including contact with aromatic compounds and pH, have been fabricated. These capsules have a huge variety of possible applications in a wide range of fields. Alireza Abbaspourrad

Double emulsions with two different inner drops: We have developed an emulsification technique that encapsulates two different inner drops inside an oil drop using glass capillary devices with a dual bore injection tube. These devices have been tested with several materials (dye-containing water, tetraethylorthosilicate, ammonia hydroxide, complex mixtures of triglycerides) and have the potential for general applicability. Laura Adams

Janus emulsions: Stable non-spherical double emulsions with ultra-thin shells and with different components can be produced in large quantities using microfluidics. Having a non-spherical shape means these double emulsions can travel in fluid streams differently than their spherical counterparts, release their cargo and pack together differently. The ability to compartmentalize different fluids in the same container also makes these useful for a wide variety of applications. We can exquisitely control the size and number of compartments. Laura Adams

Topological emulsions: Characteristics of topology can be generated inside drops with at least two different sizes of inner drops using multi-bore capillary microfluidic devices. These topological double emulsions are a result of confinement between smaller drops and a larger central drop that are contained in an immiscible fluid. Laura Adams

One-step preparation of W/W/O emulsions using glass capillary device: We are studying one-step preparation of W/W/O emulsions using glass capillary devices. There are some combinations of two aqueous polymer solutions that shows phase separation. One of the most well-known systems is the combination of dextran solution and PEG solution. This interesting property enables us to develop W/W/O emulsions. Kazuki Akamatsu

Assembly and characterization of responsive microspheres: Microcapsules and microspheres that change their permeability, size or stiffness if externally stimulated with light or magnetic fields are attractive delivery vehicles. I work on the assembly and characterization of microcapsules and microspheres that change their permeability and stiffness if exposed to light. Esther Amstad

Giant unilamellar lipid vesicles: We are using glass capillary microfluidic devices to fabricate lipid vesicles using double-emulsions with ultrathin-shell as templates. The obtained vesicles are unilamellar, monodisperse in size and uniform in composition. Laura Arriaga

Supercooled Liquid Droplets: Harnessing the precise fluid controls and small length scale features of PDMS microfludics, we study the freezing of 10-100 micron diameter water or oil droplets. Understanding the behavior of supercooled drops is of use in materials templating and biological assays. Don Aubrecht

Fluid flow in porous media: Understanding the physics of how fluids move through porous materials is quite an important problem: for example, a common way of trying to recover oil trapped in sedimentary rock is to pump another fluid through to push the oil out. I am studying the basic physics associated with this process. Sujit Datta

Capsules as Timestamp Sensors: I am developing smart sensors to exhibit an irreversible and detectable state change when exposed to oil reservoir conditions. An important requirement for all such irreversible state change smart sensors is some form of clocking mechanism that will provide a measure of exactly when the smart sensor has been triggered. This will enable identification of the exact location within the reservoir at which the stimulus occurred. Our strategy is to detect the timing of sensing events by developing packaging that undergoes a physicochemical change at a preset time, thereby providing timestamp information. By incorporating a range of preset response timestamps, we will reconstruct the time and environment behavior of the sensing package and hence of the reservoir itself. Nick Carroll

Nanoparticle-stabilized microbubbles: We use glass capillary microfluidics to make nanoparticle-stabilized microbubbles that are useful as contrast agents for seismic imaging of oil reservoirs; moreover, they must be stable at hydrostatic pressures. Wynter Duncanson

Kelvin's problem: the question of how to partition space into cells with equal volume while minimizing surface area, has intrigued physicists over 100 years. We are studying this problem using monodisperse emulsion drops generated by microfluidic technique and making new polyhedron microparticles from densely-packed drops. Jing Fan

Nanoliposomes, Phospholipid Liposomes, and Polymersomes for Drug Delivery: In order to improve the delivery of drugs to the target area, a number of different capsules for drugs are being developed. The ideal particle will be safe and stable, able to deliver a targeted dose of drug only to treatment areas. Mingtan Hai

Porous microcapsules: Microcapsules, whose membranes are regularly perforated, show selective permeability of encapsulated materials depending on their size, which is a useful property for delivery of drugs, cosmetics, and nutrients and immune-isolation of living cells. We have fabricated well-defined pores which connect internal and continuous spaces of microcapsules by combining a novel microfluidic technology to produce double-emulsion drops with an ultra-thin shell and controlled anchoring of colloids at fluid-fluid interface. Shin Hyun Kim

Clogging in microfluidic devices: Nearly every application involving fluid relies heavily upon filtration, yet the function of filter design is not well understood. Using soft lithography, we construct microfluidic devices that replicate filter features such as their pore size distribution and we test these devices by clogging them with micro particles and cells. Sorell Massenburg

Nanomaterials for advanced drug delivery: Nanomaterials such as nanoparticles, nanocapsules, micelles, micro/nanoemulsions, liposomes, polymersomes and nanoporous materials are very promising tools that are capable to change the way certain devastating diseases - including cancer - are being treated. The successful development of a drug delivery system based on the nanostructures strongly depends on the ability to control stability and properties of these colloidal species in self-assembling and structured media. I focus my research on adapting microfluidic technology for creating a library of nanoparticulate drug delivery systems for both small molecules and biotherapeutics. Sabiruddin Mirza

Functional macro-structures of inorganic nanoparticles constructed by microfluidic capillary devices: We can access a large library of empirically achieved synthetic protocols for homogeneous nanocrystals in terms of their composition, size, and shape. Diverse 2-D and 3-D assembly of nanocrystals have been demonstrated experimentally with a long-range order because their physical properties can be tuned by changing their composition, size, and surface ligand, allowing for control over the interparticle interactions. Jungwon Park

Polymersomes with special functions: Polymersomes are of great importance for applications in delivery of active materials such as drugs, food additives, cosmetics, living cells and enzymes. Here, we fabricated large numbers of stable polymersomes with special functions by using glass capillary microfluidics to prepare W/O/W double emulsions. Shaobing Zhou