Research
Selected Topics
A thin section through a scale from a butterfly wing revealing a single gyroid photonic crystal, imaged with TEM. 10 micron liquid droplets resting on a soft surface spontaneously migrate from stiff to soft regions, here indicated by the dark bands running from the top to the botton. Droplets have been false colored. The adhesion of microscopic particles to a lipid bilayer drives them to assemble, mimicking proteins that regulate the shape of cell membranes. Imaged by optical microscopy. A fluorescent microscopy composite image showing some of the essential machinery used by cells to attach to their surroundings. The green spots show points of contact between the cell and its environment. The red is the actin cytoskeleton and the blue is the nucleus.
Directed self-assembly of a photonic crystal.
Today's engineers strive to make devices that are more energy effi cient and sustainable. Living organisms meet these criteria beautifully. Yet the materials used by biology are very diff erent than the steel, silicon and plastic preferred by engineers. The bulk of living tissues are made of soft materials.These materials are so soft that thermal fluctuations can significantly perturb their microscopic structure, which typically has a characteristic length scale larger than molecular dimensions.
Why don't we build more devices out of soft materials? One reason is that we simply do not understand many of the physical principles that govern the structure and properties of soft materials. A second reason is that we have not assembled a powerful cohort of design principles to take advantage of their novel properties.
Our research program aims to elucidate the physics and design principles of soft materials. We attack the problem from two ends. First, we study the basic physics of simple soft matter systems, typically polymers or colloids. These systems are ideal for their tractability and clear demonstration of the essential phenomena. Additionally, we collaborate with biologists studying the physiology of cells.