Morphology represents a hitherto unexploited source of specificity in microfluidic particle separation and may serve as the basis for label-free particle fractionation. There is a wealth of morphological changes in blood cells due to a wide range of clinical conditions, diseases, medication and other factors. Also, blood-borne parasites differ in morphology from blood cells. We present the use of

We demonstrate that the detected emission intensity from YOYO-labeled DNA molecules confined in 180 nm deep Si/SiO2 nanofunnels changes significantly and not monotonically with the width of the funnel, an emission enhancement that is only detected for emitted light polarized parallel to the channel. We explain the enhancement effect as being due to optical phenomena in the channels. The enhancemen

We have built an array of vertical nanotubes connected by a subsurface nanofluidic channel. The nanotube system is to be used for cell injections. By culturing cells on top of the nanotubes the cells will be pierced and molecules can enter the cells via the subsurface channel. Several channels can be made on the same sample and different molecules can be injected into different subpopulations of c

Deterministic lateral displacement (DLD) is a powerful bimodal separation scheme [1] based on fluid flow through regular obstacle arrays that in its basic embodiment sends suspended particles in two different directions as a function of size. We show that without the need to seal devices and without the need for fluidic connections or pumps, particle separation can be achieved by the passive flow

Deterministic lateral displacement (DLD) is a powerful bimodal separation scheme [1] based on regular obstacle arrays that in its basic embodiment sends particles in two different directions as a function of size. We add functionality to the technique by including gravitational forces, as a perturbation to particles transported by fluid flow, and as a way of transporting the particles through a st

Conventional fractionation techniques fail to fully benefit from the variety in morphology and shape that is found among biological particles. Although light scattering in conventional FACS gives some information on the size and morphology of a particle, it is generally not capable of giving a definite number on specified dimensions of a small object. We demonstrate an approach where we select whi

We demonstrate fluidics realized in thin film plastic foils patterned using roll-toroll nanoimprinting lithography (rrNIL). Realizing fluidics devices in thin plastic foils opens up for parallel operation in stacked devices. It also provides a convenient format for storage and distribution of the devices.

We present experimental results and simulations on a simple method for tunable particle separation based on a combination of Deterministic Lateral Displacement (DLD) and Insulator Based Dielectrophoresis (I-DEP). Rather than deriving its tunability from its elastic properties[1], our present device uses an applied AC field to perturb the particle trajectories in the pressure-driven flow and is the

We demonstrate direct visualization of melting mapping of DNA stretched in nanoscale channels[1] using standard staining methods and epifluorescence microscopy to gain information on the local AT/GC ratio along large DNA molecules. Our development opens up a novel route to mapping of large-scale genomic variations.

The local alignment of DNA stretched in nanofluidic channels is measured using polarization sensitive detection. With increased degree of stretching the polarization anisotropy increases both in the deGennes and the Odijk regime. The technique is expected to find use in studies of, for example, local conformational changes in polymer physics in confined spaces, studies of protein-DNA interactions

In this work, the near-field and far-field electric magnetic (EM) wave distributions of metallic slits was observed using tapered fiber probe and modelled using finite difference time domain (FDTD) computer simulations. The EM wave field distribution from rectangular slits with widths 100 nm, 300 nm, and 500 nm was mapped with excitation wavelength λ = 532 nm. λ/2 can be considered a characteristi

Chip based bio/chemical analysis relies on networks of fluidic channels that are connected to reaction chambers and sensors. For sensitive detection it is important to scale down the size of the channels so that they approach the relevant length scales of the molecules of interest. Here we have made sealed channels on the 100 nm scale using nanoimprinting to pattern the sacrificial polymer polynor

Recently, we reported a microfabricated "DNA prism" device that continuously sorts large DNA molecules (61 kilobase pair to 209 kb) according to size in 15 seconds. In this paper, we develop models to understand and optimize the device. The device's complicated characteristics are explained poorly by a simple model based on the assumption that DNA molecules are fully stretched. Assuming DNA molecu

It is difficult to introduce long genomic DNA molecules into nanometer scale fluidic channels directly from the macroscale world because of the steep entropic barrier caused by necessary stretching of the polymer. We present a very simple technique using optical lithography to fabricate continuous spatial gradient structures which smoothly narrow the cross section of a volume from the micron to th

We made uniform arrays of nanometer scale structures using nanoimprint lithography over large areas (100 mm wafers). The nanofluidic channels were further narrowed and sealed by techniques that are based on nonuniform deposition. The resulting sealed channels have a cross section as small as 10 nm by 50 nm, of great importance for confining biological molecules into ultrasmall spaces. These techni

Long double-stranded DNA molecules were separated in microfabricated hexagonal arrays in less than 1 min, several orders of magnitude faster than by using conventional technology. DNA samples were first concentrated at the entrance to the array in a thin band by entropic focusing. They were then separated by pulsed field electrophoresis. T4 (168.9 kbp) and λ (48.5 kbp) DNAs could be resolved into

A new technology that provides high optical resolution as well as very high data rates for moving molecules is presented. An important aspect of the device is the dependence of both the near-field radiation pattern and the far-field transmission of a thin slit on the polarization of the incident light.

We show that a careful analysis of the Navier-Stokes equation in the low Reynolds number limit has two distinct solutions, one valid for a deep, thin curtain of flow and the other for a thin wide flow. We derive a solution to the latter situation and use the results to develop a new way to control fluid flows in thin, wide sheet flow.