• Østergaard, Peter Friis
• Marie, Rodolphe Charly Willy
• Cech, Jiri
• Christiansen, Thomas Lehrmann
• Tanzi, Simone
• Matteucci, Marco
• Taboryski, Rafael Jozef

Abstract

Microfabricated single-cell capture and DNA stretching devices have been produced by<br/>injection molding. The fabrication scheme employed deep reactive ion etching in a silicon<br/>substrate, electroplating in nickel and molding in cyclic olefin polymer. This work proposes<br/>technical solutions to fabrication challenges associated with chip sealing and demolding of<br/>polymer high-volume replication methods. UV-assisted thermal bonding was found to ensure a<br/>strong seal of the microstructures in the molded part without altering the geometry of the<br/>channels. In the DNA stretching device, a low aspect ratio nanoslit (1/200) connecting two<br/>larger micro-channels was used to stretch a 168.5 kbp DNA molecule, while in the other<br/>device single-HeLa cells were captured against a micro-aperture connecting two larger<br/>microfluidic channels. Different dry etching processes have been investigated for the master<br/>origination of the cell-capture device. The combination of a modified Bosch process and an<br/>isotropic polysilicon etch was found to ensure the ease of demolding by resulting in slightly<br/>positively tapered sidewalls with negligible undercut at the mask interface.

Topics

• microstructure
• polymer
• nickel
• Silicon
• isotropic
• injection molding
• plasma etching
• dry etching