Single-molecule manipulation studies open a door for a close-up investigation of complex biological interactions and properties at the molecular level.  In these studies, single biomolecules are pulled while their force response is being monitored.  The process is often nonequilibrium and, therefore,...

Cytotoxic T cells accomplish their task through the localized secretion of molecules that kill tumor and virus-infected cells. The entire process is largely orchestrated by the molecular motor protein dynein that carries cargo (secretory vesicles) along microtubules towards the microtubule organizing...

A central goal in neuroscience is to understand how collective neural activities give rise to complex behaviors. The millimeter long roundworm C. elegans appears to be an ideal model system to study neural circuit and behavior owing to its anatomical simplicity and genetic tractability. My research centers...

Motility offers bacteria survival benefits, and is important for bacterial pathogenicity. Many swim by rotating thin helical filaments, each driven at its base by a reversible rotary motor, powered by an ion flux. Studies of the physiology of the bacterial flagellar rotary motor have been limited to...

Acoustic beams can exert radiation forces and/or torques on objects, allowing, for example, manipulation of cells in suspension, assessment of viscoelastic properties of biological tissues, and targeted drug and gene delivery. I will present analyses of forces and torques exerted by acoustic beams on...

Before an Escherichia coli cell divides to give two viable daughter cells, the constantly growing cell must replicate, topologically decatenate, and spatially segregate its genetic materials. These processes pose non-trivial, conceptual questions at the interface between physics and biology....

Protein drugs delivered via subcutaneous injection represent some of the most promising therapies for a variety of diseases, including treatment of cancer. However, a major challenge for this technology is how to reliably formulate concentrated (>250 mg/ml), low viscosity (i.e., syringeable) solutions...

Biopolymer networks perform many essential functions for living cells. Most of these networks show a highly nonlinear mechanical response that is well-studied on the macroscopic scale. While much work has been done to connect the macroscopic responses of networks to microscopic parameters, such...

Biopolymer networks perform many essential functions for living cells. Most of these networks show a highly nonlinear mechanical response that is well-studied on the macroscopic scale. While much work has been done to connect the macroscopic responses of networks to microscopic parameters, such...