Research Opportunities
Multi-Component Physics
Turing Patterns and Spontaneous Symmetry Breaking
As a postdoc, I develop techniques in the Weitz lab to make all kinds of multi-component double emulsions, different types of drops inside of drops. Here I show an example of my work where the inner drops are of different sizes. A drop containing a relatively large drop in the center and smaller, darker drops on the perimeter is shown in the image on the left. These drop formations are examples of Turing patterns and are ideal systems to study spontaneous symmetry breaking using Belousov-Zhabotinsky chemical reactions inside the smaller drops that are arranged in an one dimensional loop.
Supersolid and Superglass states inside Nearly Frictionless Containers
A superglass state is a quantum state of matter in which atoms in an amorphous structure flow without resistance and a supersolid state is a quantum state of matter in which atoms in a crystalline lattice flow without resistance. A classical analog to these quantum systems is nearly frictionless rotating honeycomb or disordered water-oil-water double emulsions. This proposed investigation is concerned with the interplay between disorder, or the lack of, and the fluidity of drops confined in a nearly frictionless, 'superbowl' container. The resonances of these structures will be probed with acoustic waves while the drops are oscillating backwards and forwards. In these experiments, we will record the dynamics of the rotating drops using a fast camera. We can study the motion of “atoms” or follow pockets that lead to plastic deformation. Atoms are represented by orange water drops and held together by capillary attraction forces. These forces represent the binding forces of electrons in a metal. We can add disorder by adding different size inner drops. How does the frequency depend on the crystallinity or disorder in the system, the container’s size, and the viscosity of the fluid in the container? These are some of the questions that we will address.
Applications for Janus and Cerberus Emulsions:
Bio-robots
Traditional rigid body robots are limited in their ability to interact with their environment and maneuver in highly congested environments, such as the human body. Micron-size bio-robots that are made of soft materials can navigate through constrictions in a delicate manner which is important for applications in curing and diagnosing diseases in humans. These non-spherical, multi-component double emulsions can flow through channels containing obstacles while still reaching their desired destination.
Nanoparticles and Double Emulsions: New Materials
I have encapsulated nitrogen gas inside rigid shells of nanoparticles to form core-shell structures, or encapsulated bubbles, using the strategy developed by Dayeon Lee’s group at the University of Pennsylvania. Different nanoparticle solutions can be used to create spherical and non-spherical structures with different electric, magnetic and mechanical properties. The top two images are scanning electron microscope images taken by Esther Amstad.