Low-Cost Microfluidic Single-Use and On-Board Reagent Storage Using Laser-Printer Technology Shau-Chieh Wang ( 王少傑 ) NTHU / MSE -- January 5, J. L. Garcia-Cordero, F. Benito-Lopez, D. Diamond, J. Duceree, and A. J. Ricco, MEMS 2009

★ Introduction ★ Design and operation of the valves ★ Design of the storage reservoirs ★ Fabrication ★ Results and discussion ★ Conclusions ★ Future work NTHU / MSE 2Outline

Point-of-care (POC) diagnostic devices require portability, disposability, low-cost, simplicity of use, and temperature independence. Microfluidic and lab-on-a-chip technologies have the potential and the toolset to make POC diagnostic systems a reality. The complexities of integrating and fabricating them at low cost are many and the challenges are daunting. This paper presented a technology for low-cost production of valves that can enable on-chip long-tern wet reagent storage. NTHU / MSE 3Introduction

4Introduction V. Linder et al. Anal. Chem. 77, 64 (2005) The storage of reagents inside plastic tubing in liquid plugs separated by air. This method does not provide a sealed physical barrier is ill-suited to storage beyond a few hours. A simple single-use valve is used to alternate it.

5 Design and Operation of the Valves NTHU / MSE

6 Design of the Storage Reservoirs NTHU / MSE

7Fabrication This paper used CO 2 laser to cut polymer layers and laminated by a thermal roller laminator. A laser-printer (resolution: 600 dpi) was used to print dots onto a transparency film. Devices were mounted in a disk, and a DC motor was used to rotate the disk. A laser diode (wavelength 650 nm, power 150mW) was used to melt the plastic in less than one second.

8 Results and Discussion NTHU / MSE (5000 rpm)

9 Results and Discussion NTHU / MSE (5000 rpm)

NTHU / MSE 10Conclusions This paper presented new laser-printed valves which can store solutions for 30 days without mechanical components in the valve and its actuation. This technology can be adapted to multilevel microfluidics where layers of microfluidic channels are separated by valve layers. This technology is simple, low cost, and using lower laser powers to other technologies.

Future work NTHU / MSE 11  The future work will involve the full characterization of laser valves. Melting temperatures The effects of any chemically active residue of the melting process

NTHU / MSE