Taekjip Ha is Bloomberg Distinguished Professor of Biophysics and Biophysical Chemistry at Johns Hopkins University and an HHMI Investigator, widely regarded as one of the founders of single-molecule biophysics. He pioneered single-molecule Forster Resonance Energy Transfer (smFRET) as a tool for watching individual biomolecules move, fold, and react in real time, enabling researchers to observe dynamic conformational changes invisible to ensemble techniques. Ha's laboratory has applied smFRET and single-molecule force spectroscopy to decode the mechanisms of helicases, polymerases, nucleosomes, CRISPR-Cas complexes, and RNA-protein assemblies. He developed CoSMoS (co-localization single-molecule spectroscopy) and numerous microfluidic single-molecule platforms that are now commercialized and widely distributed. Ha's work has fundamental implications for understanding DNA repair, replication, transcription, and viral entry mechanisms. His laboratory is a leading purchaser and developer of custom TIRF microscopes, optical traps, single-molecule fluorescence detection systems, and microfluidic devices, and he regularly collaborates with instrument manufacturers on next-generation single-molecule systems. Ha has received the Ho-Am Prize, the Biophysical Society's Distinguished Lecture, and election to the National Academy of Sciences and American Academy of Arts and Sciences.