title: Emergence of upstream swimming via a hydrodynamic transition.
abstract: We demonstrate that upstream swimming of sperm emerges via an orientation disorder-order transition. The order parameter, the average orientation of the sperm head against the flow, follows a 0.5 power law with the deviation from the critical flow shear rate (γ-γ_{c}). This transition is successfully explained by a hydrodynamic bifurcation theory, which extends the sperm upstream swimming to a broad class of near surface microswimmers that possess front-back asymmetry and circular motion.
authors: Department of Biological and Environmental Engineering, Cornell University, Ithaca, New York 14853, USA.
authors: Chih-Kuan
authors: CK
authors: Tung
authors: Department of Biomedical Sciences, Cornell University, Ithaca, New York 14853, USA.
authors: Florencia
authors: F
authors: Ardon
authors: School of Chemical and Biomolecular Engineering, Cornell University, Ithaca, New York 14853, USA.
authors: Anubhab
authors: A
authors: Roy
authors: School of Chemical and Biomolecular Engineering, Cornell University, Ithaca, New York 14853, USA.
authors: Donald L
authors: DL
authors: Koch
authors: Department of Biomedical Sciences, Cornell University, Ithaca, New York 14853, USA.
authors: Susan S
authors: SS
authors: Suarez
authors: Department of Biological and Environmental Engineering, Cornell University, Ithaca, New York 14853, USA.
authors: Mingming
authors: M
authors: Wu
mesh_terms: D000818:Animals; D002417:Cattle; D057446:Hydrodynamics; D008297:Male; D046210:Microfluidic Analytical Techniques; D008954:Models, Biological; D013094:Spermatozoa / Q000502:physiology*; D013550:Swimming / Q000502:physiology*