Jaap H. M. Neijzen

Rapid, high sensitivity, point-of-care test for cardiac troponin based on optomagnetic biosensor

BACKGROUND We present a prototype handheld device based on a newly developed optomagnetic technology for the sensitive detection of cardiac troponin I (cTnI) in a finger-prick blood sample with a turnaround time of 5 min. METHODS The test was completed in a compact plastic disposable with on-board dry reagents and superparamagnetic nanoparticles. In our one-step assay, all reaction processes were precisely controlled using electromagnets positioned above and below the disposable. Nanoparticle labels (500 nm) bound to the sensor surface via a sandwich immunoassay were detected using the optical technique of frustrated total internal reflection. RESULTS A calibration function measured in plasma demonstrates a limit of detection (mean of blank plus 3-fold the standard deviation) of 0.03 ng/mL cTnI. A linear regression analysis of the region 0.03-6.5 ng/mL yields a slope of 37+/-4, and a linear correlation coefficient of R2=0.98. The measuring range could be extended substantially to 100 ng/mL by simultaneously imaging a second spot with a lower antibody concentration. CONCLUSIONS The combination of magnetic particles and their fine actuation with electromagnets permits the rapid and sensitive detection of cTnI. Because of the potential high analytical performance and ease-of-use of the test, it is well suited for demanding point-of-care diagnostic applications.

Deep-UV liquid immersion mastering of high density optical discs

A liquid immersion technique has been developed to increase the numerical aperture (NA) of a 257 nm optical disc mastering system from 0.9 to 1.2. The resolution enhancement was demonstrated in grooves. In 25 nm resist, 70 nm wide grooves were written with liquid immersion, compared to 100 nm wide grooves far-field. Liquid immersion was also successfully applied to mastering of read-only-memory (ROM) discs for the Blu-ray Disc system. Replicated discs with a density corresponding to 25 GB in a single layer on a 12 cm disc at a track pitch of 320 nm showed a jitter of 6.9% with limit equalizer.

Liquid Immersion Deep-UV Optical Disc Mastering for Blu-ray Disc Read-Only Memory

The liquid immersion mastering technique has been successfully applied to the mastering of read-only memory (ROM) discs for the Blu-ray disc (BD) system. Replicated discs with a density corresponding to 25 GB in a single layer on a 12 cm disc showed a bottom jitter of less than 5%. Results concerning process latitude and disc uniformity are presented. A full-format 25 GB ROM disc containing over 2 h of high-definition video content has been mastered according to the BD target specification. The results obtained for a reduced channel bit length show the potential of liquid immersion mastering for densities beyond 31 GB per layer.

Multiple scattering of light from polymer dispersed liquid crystal material

Light scattering from polymer dispersed liquid crystal (PDLC) material has been studied experimentally and by Monte Carlo simulation. Light scattering was measured as a function of both scattering angle and cell thickness. The cell thicknesses of practical interest are in an intermediate regime where neither single scattering nor light diffusion applies. Both the angular and the thickness dependence of the scattering intensity can be described accurately by a Monte Carlo simulation of multiple scattering from a homogeneous distribution of independent scatterers. The model smoothly interpolates between the single scattering limit for thin cells and the diffusion limit for thick cells. It can easily be extended to include any specific feature of a scattering display system.

Reflective direct-view LCDs using polymer-dispersed liquid crystal (PDLC) and dielectric reflectors

— Novel color and monochrome reflective direct-view display configurations have been developed by combining light-scattering PDLC layers with dielectric reflectors. Diffuse reflectances comparable to white paper were achieved.

Improved wafer stepper alignment performance using an enhanced phase grating alignment system

Processes such as chemical mechanical polishing and spin coating can result in the asymmetric deformation of alignment marks. In this paper, the effects of such asymmetric mark deformations on the accuracy of the stepper alignment system are investigate. An advanced phase grating alignment system is presented which is more robust against the above mentioned process-induced alignment deviations. The potential of the new alignment system will be illustrated with result of both numerical simulations and experimental measurements. Various process modules that are known to cause mark deformations have been investigated.

Two-Dimensional Optical Storage Mastering: Adding a New Dimension to Liquid Immersion Mastering

We present a novel-mastering concept of Two-dimensional structures using a single writing spot. We describe its implementation for the existing liquid immersion mastering set-up, from initial concept and feasibility analysis to mastered discs of up to 60 GB/layer data density.

Deep-UV liquid immersion mastering of high-density optical discs

A water immersion technique has been developed to increase the numerical aperture (NA) of a 257 nm optical disc mastering system from 0.9 to 1.2. The developed system is capable of performing point exposures on a rotating disc at scanning velocities of more than 5 m/s. Gas inclusion in the immersion liquid, either from the photo-resist or through the dynamic movement of the substrate could be avoided. Furthermore, unwanted mechanical disturbances were sufficiently suppressed. Contamination of the photo-resist was avoided through careful handling of the water that was applied as immersion liquid. The resulting resolution enhancement was demonstrated in grooves. In 25 nm Novolac type resist, 70 nm wide grooves were written with liquid immersion, compared to 100 nm wide grooves at NA = 0.9. Liquid immersion was also successfully applied to write the master substrate from which a ROM disc can be made through injection molding. ROM discs for the recently launched Blu-ray Disc system have been successfully written with a density corresponding to 25 GB in a single layer of a 12 cm disc.

Multiple Light Scattering from Polymer-Dispersed Liquid Crystals

Abstract Measurements and Monte Carlo simulations of the angular distribution of light scattered from wedge-shaped Polymer-Dispersed Liquid Crystals (PDLCs) are reported. The simulation model is based on two length scales: the scattering mean free path and the transport mean free path. The simulation reproduces the experimental angular distribution of multiply scattered light as a function of sample thickness if the angular distribution in each scattering event is taken as a Mie distribution or as a Lorentzian in the cosine of the scattering angle. The experimental parameters are in the intermediate range where models based on either single or diffusive scattering do not apply.

Liquid immersion deep-UV optical disc mastering for high data capacity ROM discs

In this paper we describe the liquid immersion mastering technique and its application to the mastering of ROM discs for the Blu-ray Disc system and for ROM discs with considerably higher data densities. Replicated 25GB BD-ROM discs were evaluated using a standard blue test player (λ=405nm, NA=0.85). A bottom jitter value with limit equalizer of less than 5% was measured. Also the values of asymmetry, normalized push pull and symbol error rate were well within the Blu-ray Disc format specification, offering a large process window. Full-format BD-ROM test discs with high definition video content were mastered and their successful read-back was demonstrated. In addition we show that liquid immersion mastering can successfully be applied for mastering of considerably higher densities. Measurements on replicated discs up to data densities above 40GB per layer are discussed. The present results demonstrate that liquid immersion mastering is a proven technology for the mass-production of high data capacity ROM discs.