Efficient swimming of biologically carangiform robotic fish has been investigated by using a novel experimental method. The laboratory robotic fish model, which follows an exact replica of Saithe, is self-propelled on a servo towing system. The forward towing speed is determined by the fluid force acting on the robotic fish, as the fish undulates its body in the water. The importance of the sel...

Hair-like appendages called cilia on the surface of a microorganism such as Paramecium or Opalina beat highly synchronized and form so-called metachronal waves that travel along the surfaces. In order to study under what principal conditions these waves form, we introduce a chain of beads, called rowers, each periodically driven by an external force on a straight line segment. To implement hydr...

In this study, we simulate the electrophoretic motion of a bio-polymer through a synthetic nanopore in the presence of an external bias voltage by considering the hydrodynamic interactions between the polymer and the fluid explicitly. The motion of the polymer is simulated by 3D Langevin dynamics technique by modeling the polymer as a worm-like-chain, while the hydrodynamic interactions are inc...

We present a microfluidic particle-trap array that utilizes negative dielectrophoresis (nDEP) force and hydrodynamic force. The traps are located at the stagnation points of cylindrical pillars arranged in a regular array, and they can function as both single-particle traps (capable of discriminating particles based on size) and multiparticle traps (capable of controlling the number of particle...

Six buildings were overturned in the town of Onagawa during the 2011 Great East Japan tsunami. This study investigates the possible failure mechanisms of building overturning during tsunami flow. The tsunami inundation depth and flow velocity at each overturned building were recalculated by using a tsunami numerical simulation and verified using a recorded video. The overturning moment is a res...

Cell adhesion in the presence of hydrodynamic forces is a critical factor in inflammation, cancer metastasis, and blood clotting. A number of assays have recently been developed to apply forces to small numbers of the receptor–ligand bonds responsible for adhesion. Examples include assays using hydrodynamic shear in flow chambers or elastic probe deflection assays such as the atomic force micro...

The surface and hydrodynamic forces between individual oil droplets in solution can provide insight into both emulsion stability and processes such as drop coalescence in liquid-liquid extraction. We present the first measurements of the interaction forces between alkane droplets in aqueous solution using atomic force microscopy. The radii of the droplets were well below the capillary lengths f...

A method to simulate bodies suspended in a Lattice Boltzmann solvent is proposed. It is based on a generalized reaction force that enforces no-slip boundary conditions at the fluid–body interface as the limiting case of an iterative procedure. A smooth version of the Heaviside function allows to treat spherical particles of arbitrary size and produces smooth hydrodynamic forces as particles mov...

We introduce a multiplex particle focusing phenomenon that arises from the hydrodynamic interaction between the viscoelastic force and the Dean drag force in a microfluidic device. In a confined microchannel, the first normal stress difference of viscoelastic fluids results in a lateral migration of suspended particles. Such a viscoelastic force was harnessed to focus different sized particles ...

As part of the Post-Katrina project, a multi-fluidic speed-modulating (MFSM) micropump module combined with Tesla valves and hydrodynamic focusing micro-fluidic channels was designed, fabricated, and tested to help regulating sample flow across the nanowire-seeded sensor areas embedded in microfluidic channels. The size of the entire module is 33 mm x 25 mm x 8mm and comprises of three MFSM mic...