Flows in a microchannel are laminar, which means that mixing depends on only inter-diffusion. A micromixer plays an important role in obtaining fast diagnosis results in the fields of m-TAS (total analysis system), Bio-MEMS and LOC (lab-on-a-chip). In this paper, we propose a new active mixer with vertical flow placement via a series of inlets for micromixing. This has two inlets on the same ax...

Combustion of wastes is an effective disposal technology. Although there are many examples of application in industry, severe environmental concerns are raised regarding the emissons from incinerators. Thermal treatment plants are usually comprised of a primary combustion chamber followed by a second combustion chamber, as schematically described in Fig. 1. During the oxidation of solid and liq...

We describe a simple and low cost nonlinear gradient former. The apparatus is derived from a 20 ml syringe and was used to build up sucrose gradients (1) for the separation of DNA fragments needed for the construction of a cosmid library. The setup is given in Figure 1. The lower chamber underneath the plunger is the mixing chamber containing a given volume of the lower concentrated solution, t...

A microfluidic islet perifusion device was developed for the assessment of dynamic insulin secretion of multiple islets and simultaneous fluorescence imaging of calcium influx and mitochondrial potential changes. The device consists of three layers: first layer contains an array of microscale wells (500 mum diameter and 150 mum depth) that help to immobilize the islets while exposed to flow and...

This paper discusses thermodynamic models of air inside pneumatic actuator chambers. In servo-pneumatics common practice, these models are simplified by neglecting the temperature dynamics. Classical models in the literature assume the temperature inside the pneumatic chamber either to be constant or to follow a polytropic law. Furthermore, the mixing process of air entering the chamber and hea...

Cloudy air, containing small (∅ 14 μm) water droplets, undergoes mixing with the unsaturated environment inside the cloud chamber in the process resembling smallest scales of entrainment and mixing in real clouds. Particle Image Velocimetry (PIV) applied to images from the chamber interior is used to investigate dynamics of the process in scales from 1.2 mm to few centimeters. A special algorit...

The first experimental evidence of mixing enhancement in a microfluidic system using contactless dielectrophoresis (cDEP) is presented in this work. Pressure-driven flow of deionized water containing 0.5 μm beads was mixed in various chamber geometries by imposing a dielectrophoresis (DEP) force on the beads. In cDEP the electrodes are not in direct contact with the fluid sample but are instead...

This paper presents an integrated digitally controllable microfluidic system for continuous solution supply with a real-time concentration control. This system contains multiple independently operating mixing modules, each integrated with two vortex micropumps, two Tesla valves and a micromixer. The interior surface of the system is made of biocompatible materials using a polymer micro-fabricat...

In centrifugal microfluidics, dead volumes in valves downstream of mixing chambers can hardly be avoided. These dead volumes are excluded from mixing processes and hence cause a concentration gradient. Here we present a new bubble mixing concept which avoids such dead volumes. The mixing concept employs heating to create a temperature change rate (TCR) induced overpressure in the air volume dow...

This paper reports the investigation of mixing phenomena caused by the interaction between a uniform magnetic field and a magnetic fluid in a microfluidic chamber. The flow system consists of a water-based ferrofluid and a mixture of DI water and glycerol. Under a uniform magnetic field, the mismatch in magnetization of the fluids leads to instability at the interface and subsequent rapid mixin...