Abstract: Over seven million people die of cancer worldwide each year. The high mortality is mainly due to the lack of early cancer detection modalities, especially for internal organs. CT, MRI and ultrasound imaging have issues of low resolution, low contrast, safety or high cost. Several optical imaging techniques provide high-resolution cross-sectional information suitable for in vivo noninvasive early cancer diagnosis. However, these optical imaging systems are typically bulky and slow, and thus are difficult to apply to internal organs where most cancers are originated. Microelectromechanical systems technology offers the advantages of small size and fast scan speed, providing a tremendous opportunity for realizing real-time in vivo endoscopic imaging. In this talk, a unique MEMS technology that can create large-range, multi-axis, rapid scanning micromirrors and microlenses will be introduced. These MEMS devices in turn enable endoscopic optical “biopsy” modalities, resulting in a paradigm shift of optical imaging of internal organs. In particular, MEMS-based 3-D endoscopic optical coherence tomography imaging and confocal imaging will be introduced and in vivo experimental results of animals will be presented. Huikai Xie is a professor at the department of electrical and computer engineering of the University of Florida. He received his B.S., M.S. and Ph.D. degrees in electrical engineering from Beijing Institute of Technology, Tufts University and Carnegie Mellon University, respectively.