Si is a beamline scientist at the Advanced Photon Source. During her career at Argonne, Si has made a notable impact to the nano-imaging and microscopy. She has lead several strategic efforts including the development of the Bionanoprobe, which is a hard X-ray scanning nanoprobe with cryogenic capabilities and the first instrument of its kind in the world.

Si’s primary research interests and expertise lie in the areas of X-ray microscopy, cryogenic methods, instrumentation and X-ray fluorescence data analysis. With colleagues at Argonne and collaborators from other institutions, Si has been successfully applied the advanced technologies to solve problems in a broad range of studies in the areas of  biological, biomedical, environmental and materials science.