title: Optically-controllable, micron-sized motor based on live cells.
abstract: We demonstrate rotation of live Chlamydomonas reinhardtii cells in an optical trap; the speed and direction of rotation are amenable to control by varying the optical trapping force. Cells rotate with a frequency of 60-100 rpm; functional flagella are shown to play a decisive role in rotation. The rotating cells generate torque (typically ~7500-12000 pN nm) that is much larger than that generated chemically by a dynein head in vitro (40 pN nm). The total force associated with a rotating live cell (~10 pN) suggests that activity of only a small fraction (~5%) of dynein molecules per beat cycle is sufficient to generate flagellar motion.
authors.forename: M
authors.initials: M
authors.lastname: Gudipati
authors.forename: J
authors.initials: J
authors.lastname: D'Souza
authors.forename: J
authors.initials: J
authors.lastname: Dharmadhikari
authors.forename: A
authors.initials: A
authors.lastname: Dharmadhikari
authors.forename: B
authors.initials: B
authors.lastname: Rao
authors.forename: D
authors.initials: D
authors.lastname: Mathur