[Zurück]

E. Weber, F. Keplinger, M. Vellekoop:
"Optofluidic, contact-free 1x3 light-switch fabricated on a mono-layer device";
Vortrag: Microfluidics 2012, Heidelberg, Deutschland; 03.12.2012 - 05.12.2012; in: "Proc. of uFLU 2012", (2012), S. 1 - 6.

We present an on-chip 1x3 light switch exploiting an optofluidic principle. Compared to other works mechanically moving
elements were entirely omitted, eliminating any wearing or sticking issues and nearly infinite switching sequences are possible.
Furthermore, the consumption of solutions is kept at the very minimum since no permanent flow through the device
is needed. The principle is based on total internal reflection at the solid-liquid interface of a liquid filled microfluidic
channel. Depending on the refractive index of the solution light is either reflected and guided towards the first output or
transmitted and routed to another position. Placing two channels after each other provides three possible optical outputs.
Fluorescence images were taken to evaluate the operation of the device. In accordance with that, the optical signals were
detected by photodetectors at all three outputs and verified the faultless switching characteristics. By integration of more
than two channels the number of switching possibilities can further be increased. The devices were fabricated in PDMS
enabling fast and cost-effective reproduction. For the master device fabrication a new rapid proto-typing technique applying dry resist lamination has been used. This principle is a promising approach to enhance the performance of devices implementing fluorescence analyses. Excitation light can be controlled in terms of place and exposure time allowing for an accurate and time limited activation of small sample volumes.

Optofluidics, spatial fluorescence excitation, on-chip light switch, dry resist

http://publik.tuwien.ac.at/files/PubDat_212396.pdf