Research

Roughly following the steps outlined in the OpenSPIM project, we've built a light-sheet microscope. We are using it for a number of different purposes. One current use of it is to study how DNA diffuses in different crowded environments (which is a collaboration with Dr. Rae Anderson). On the instrument development side we are working on incorporating adaptive optics into our microscope by using a deformable mirror (see cartoon).

This is a technique used to study the transport properties (like diffusion or directed motion) of objects imaged under the microscope. It is in some ways similar to dynamic light scattering. We have shown that DDM in combination with light-sheet microscopy (SPIDDM) is useful for studying light-sensitive or optically thick samples. We are interesting in further developing this combination.

We have also been exploring how point-spread function engineering (using adaptive optics) can enhance DDM.

This optical imaging technique uses the interference of light scattered by an object and light that is unscattered to image objects in three-dimensions. Previous work with DHM has investigated the diffusion of colloidal particles and how colloidal particles stick to liquid-liquid interfaces.

We are interested in studying liquid-liquid phase separation and the interface between fluid phases using aqueous two-phase systems. The video to the left shows the coalescence of colloid-dense droplets surrounded by a colloid-poor phase.

Using a simple craft-cutter we can fabricate microfluidic devices with double-sided tape and clear plastic sheets.

One application of microfluidic devices has been to observe crystals forming. We controllably mix two different chemicals in a microfluidic device and observe the nucleation and growth of crystals (see video to right).