Our Research

Soft matter physics: the study of soft, squishy, and deformable objects. Examples of soft matter are all around us. Most parts of our body (e.g. skin, tendon, blood) and many engineered materials (e.g. plastics, rubbers, foams, gels) fall under the category of soft matter. More precisely, the field of Soft Matter Physics encompasses systems where room temperature thermal energy is comparable to that of applied mechanical or thermal stresses. Soft Matter often includes structure on mesoscopic size scales (sizes anywhere from roughly 10 nm up to about 100 um; between that of a single atom but smaller than we can easily see with the naked eye).

The PoSM Lab at Harvey Mudd College studies both soft elastic solids and non-Newtonian fluids from a curiosity-driven approach. Currently we are interested in green technologies that use soft materials to address our environmental footprint. In particular, we are studying the fluid dynamics of water-processible polymers and the elastodynamics of mechanical batteries (made of materials that store and release elastic energy). By studying the underlying fundamental physics related to these systems, we aim to inform further development of green technologies.

Elastodynamics
Environmental concerns about the production and disposal of traditional electrochemical batteries has led to calls for energy storage alternatives. One possible approach is to utilize mechanical batteries: materials which store and release elastic strain energy. Beyond environmental benefits, mechanical batteries have the advantage of fast energy release (large power density), and do not face significant high-temperature performance degradation. Typical engineered systems employing elastic energy release use steel springs or soft materials such as elastomers, which have a low energy density compared to electrochemical batteries. However, recent developments of nanostructured materials (e.g. graphene,
carbon nanotubes, boron nitride ribbons) demonstrate extraordinary potential for mechanical energy storage and release, simultaneously providing high energy density and large power density.

Our work in this area is inspired by the biomechanics of some amazing organisms that store and release elastic energy to achieve astonishing kinematic performance (e.g. predatory cone snails). Studying the biomechanics of these organisms will enhance our understanding of the capabilities and limitations of elastic materials.


In our work, we will address the guiding question:
What are the physical principles determining the ultimate limits of elastic energy density and power density?



Fluid Dynamics
The solution processability of polymer coating films can reduce manufacturing costs and increase the performance
of thin film devices such as photovoltaics. Unfortunately, this processing can often involve the use of toxic solvents which negatively affect the environment and human health. Performing a life-cycle analysis on the use of various solvents points to some promising candidate solvents, of which water is ultimately the least harmful. There are a variety of hydrophilic polymer systems which allow for water processability. One interesting consequence of working with hydrophilic systems is their ability to adsorb water in humid environments. Water adsorption is important in technological applications such as filtration membranes,
coatings, microelectronics, sensors, and drug release. Many of these applications require thin films, where confinement effects become important.

In our work, we will address the guiding question:
How does the presence of water and confinement affect the physical properties of polymer coatings?