The Mechanical Analysis of the Biofilm Streamer Nucleation and Geometry Characterization in Microfluidic Channels.
Bacteria can form biofilm streamers in microfluidic channels with various geometries. Experiments show that the streamer geometry, such as its shape or thickness, depends on the fluid velocity and the geometry and curvature of the microfluidic channel. In the paper, a mechanical analysis of the flow field is made in different channels, which shows that the secondary flow in the channel is the reason for streamer nucleation and that the shear stress distribution decides the streamer geometry including shape and thickness. Through a finite elements simulation, we obtain the secondary flow forming positions in both static and rotating channels: positions that are the location of nucleation of the streamer. Thick or wide biofilm streamers occur at the points of minimum shear stress in static channels. Furthermore, in rotating channels, spiral-like streamers form, due to the helical shape of the minimum shear stress distribution. The findings may allow the prevention of biofilm formation and also the removal of bacteria adhered onto certain surfaces in channels with small cross sections. The analysis also indicates how one can obtain desirable biofilm streamers by control of the channel geometry and the loading conditions.
School of Mechanical Engineering, University of Science and Technology Beijing, Beijing 100083, China; School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USA; Laboratory of Nonlinear Mechanics, Institute of Mechanics, Chinese Academy of Sciences, Beijing 100190, China.
Xiaoling
X
Wang
School of Mechanical Engineering, University of Science and Technology Beijing, Beijing 100083, China.
Mudong
M
Hao
School of Mechanical Engineering, University of Science and Technology Beijing, Beijing 100083, China.
Xin
X
Du
School of Mechanical Engineering, University of Science and Technology Beijing, Beijing 100083, China.
Guoqing
G
Wang
Department of Materials Science, Tokai University, Hiratsuka 259-1292, Japan.
Jun-Ichi
J
Matsushita
D001422:Bacterial Adhesion; D018441:Biofilms; D003198:Computer Simulation; D020342:Finite Element Analysis; D057446:Hydrodynamics; D006863:Hydrogen-Ion Concentration; D056656:Lab-On-A-Chip Devices; D008422:Materials Testing; D044085:Microfluidics; D008962:Models, Theoretical; D011108:Polymers / Q000737:chemistry; D033081:Shear Strength; D013314:Stress, Mechanical; D013499:Surface Properties; D013696:Temperature; D014783:Viscosity
D011108:Polymers