Sascha Hilgenfeldt - Soft Condensed Matter

Associate Professor, Engineering Sciences & Applied Mathematics,
Department of Mechanical Engineering
Northwestern University
Technological Institute, room M442
2145 Sheridan Rd
Evanston, IL 60208
phone: +1-847-491-7243
fax :     +1-847-491-2178
e-mail: sascha@northwestern.edu

Engineering Sciences & Applied Mathematics and   Department of Mechanical Engineering,
McCormick School of Engineering and Applied Science, Northwestern University

We study the interfacial structure and dynamical evolution of soft condensed matter, using experiment, theory, and numerical simulation. We are particularly interested in biological soft matter on the cellular level and in systems of importance in industrial applications (colloids, foams). One focus of our research is on gas/liquid two-phase systems, consisting of single or multiple bubbles. Not only are bubbles a fascinating subject by themselves, they are also extremely useful tools to probe other soft matter. Our research spans all areas from the mathematical fundamentals of the theory to the development of engineering applications.

We collaborate with researchers all over the world from the engineering sciences, applied mathematics, physics, and medicine. Understanding soft matter requires drawing from interdisciplinary expertise in many fields, which makes the subject all the more exciting.

Bubble Biomechanics
We torture cells and lipid vesicles using ultrasonic forces mediated by tiny bubbles. Why? Because transporting, deforming, and opening cellular membranes is key to drug delivery, gene therapy, and cell diagnostics. And as yet, far too little is known about the mechanics of life.&nbps; More 		Foams
Foams are strange: consisting of gas and liquid, they mostly behave as a solid. They evolve by transport of gas (aging) and liquid (drainage). Their beautiful structure is a potentially optimal filling of space, but nobody knows precisely how to describe it.
Foams are strange, but fascinating!   More.
Single Bubbles
The simplest soft material - but that impression is deceptive. We have studied bubbles that collapse at the speed of sound, heat to over 10000 degrees, emit light, and spur complicated chemical reactions. All this is possible because they are the most efficient force actuators we know. We explore their mechanics and their uses.   More 		Colloidal Aggregates
Colloidal particles at interfaces attract or repel each other, depending on their size, charge, and other parameters. We find that, for small particles at an air-water interface, the nature of the interaction may be completely determined by the shape of the particles, with consequences for the ensuing colloidal aggregates.   More