We have successfully designed, fabricated and characterized a micro-cavity fluidic dye laser with metallic mirrors, which can he integrated with polymer based lab-on-a-chip microsystems without further processing steps. A simple rate-equation model is used to predict the average pumping power threshold for lasing as function of cavity-mirror reflectance, laser dye concentration and cavity length. The laser device is characterized using the laser dye Rhodamine 6G dissolved in ethanol. Lasing is observed, and the inRuence of dye concentration is investigated.

A simple linear electromechanical model for an electrostatically driven resonating cantilever is derived. The model has been developed in order to determine dynamic quantities such as the capacitive current flowing through the cantilever-driver system at the resonance frequency, and it allows us to calculate static magnitudes such as position and voltage of collapse or the voltage versus deflection characteristic. The model is used to demonstrate the theoretical sensitivity on the attogram scale of a mass sensor based on a nanometre-scale cantilever, and to analyse the effect of an extra feedback loop in the control circuit to increase the Q factor.

No abstract

This study presents a novel method for rapid prototyping of polymer microsystems. The method is based on excimer laser ablation of a thermally and mechanically stable polymer, such as PEEK (poly-ether-ether-ketone). A negative of the desired microsystem is laser machined in PEEK, which can then be used directly for hot embossing or injection moulding of a series of prototypes. This approach is very rapid and considerably cheaper than more traditional approaches to toolmaking, while still performing well in terms of reproduction of tool dimensions. The reduction in time and cost for a master tool using this method opens up new possibilities for testing small series in the R&D phase of a microsystem. Finally, two particular applications of the technique are presented.

No abstract

No abstract

We present a tunable microfluidic dye laser fabricated in SU-8. The tunability is enabled by integrating a microfluidic diffusion mixer with an existing microfluidic dye laser design by Helho et al. By controlling the relative flows in the mixer between a dye solution and a solvent, the concentration of dye in the laser cavity can he adjusted, allowing the wavelength to he tuned. Wavelength tuning controlled by the dye concentration was demonstrated with macroscopic dye lasers already in 1971, hut this principle only becomes practically applicable by the use of microfluidic mixing. With presently available dyes, the lasing wavelength can he tuned in an interval between 400 nm and 900 nm, depending on the specific dye. In this first. demonstration, the lasing wavelength was tuned between 568 nm and 574 nm, using a solution of m o m Rhodamine 6G in ethanol.,

No abstract