Haw Yang

The Haw Yang Lab works on problems in the general area of Biophysical Dynamics. On the more abstract level, we seek to understand the manner by which local fluctuations in a complex system may contribute to the system’s function. Examples include how proteins exploit thermally driven conformational changes to achieve their functions, how living cells modulate their intra-cellular local temperature to remain viable, how viruses or nanomedicine carriers dynamically interact with a cell to infect the cell or to accomplish cellular delivery, and how one can control the nanoscale interfacial hydrodynamical fluctuations to manipulate micro- and nano-swimmers in three dimensions (3D).

In order to address problems like these, we have successfully developed several original experimental approaches. Because many of the experiments are new, we also develop the required theories concurrently. For example, for single-molecule protein dynamics in molecular biophysics, our photon-by-photon method treats each detected photon as a data point so that the conformational distribution of a protein and the dynamical evolution of its conformational can be quantitatively evaluated with highest possible resolution without any presumed model. For cellular thermobiology, we have been actively advancing nanothermometer-based local temperature metrology that will permit us to measure the temperature of a specific cellular organelle precisely and rapidly.

For nanomedicine, we have developed the 3D multi-resolution microscopy concept, by which the current implementation allows us to make high-definition real-time motion pictures of a virus or nanoparticle with 10-μs time resolution and ~10-nm spatial localization precision in all three dimensions. For the 3D control of micro- and nano-swimmers, we have put forward the “photon nudging” idea, in which the “engine” of a self-propelled swimmer is stochastically turned on and off using a very weak laser light based on the swimmer’s location and orientation. These new experimental approaches have allowed us to look at problems from new perspectives and, in many instances, have enabled interesting new discoveries.