Abstract

Microfluidics is a quickly developing engineering science targeting transportation and handling a small volume of liquids in an increasing number of applications such as biomedical diagnostic, micro fuel cells and cooling in microelectronics [1- 2]. In particular, microfluidic devices for detection of circulating tumor cells have emerged as a promising minimally invasive diagnostic tool. Isolation of circulating tumour cells has become a central topic in cancer research where engineering and medical science converge with the common goal of capturing rare cell types in liquid biopsies as a starting point for early diagnose and the development of point of care and single cell analysis systems [3,4]. A huge variety of methods exists for the fabrication of microfluidic devices, the choice among them depends on the size and shape of the required features and on the materials to be treated. Laser micromachining, because of its non-contact nature, offers several advantages for fabricating microchannels, including the capability of fabricating complex shapes with minimal mechanical and thermal deformation [5] In the present work, a fast, simple but reliable process is reported for the fabrication of microfluidics devices using two lasers: a Nd:YVO₄ nanosecond IR laser for performing the desired structures and a CO₂ laser for reducing the damage created during the laser ablation by the Nd:YVO₄ and for improving the morphological quality of the generated microstructures. The applicability of the manufactured chips for capturing circulating tumour cells was tested with tumour cells (Hec 1A) after being functionalized with an EpCAM antibody coating. Cells were flown with media through the device allowing an interaction with the functionalised micropillars. After eluting the whole sample, chips were assessed for sensitivity and efficiency under a confocal microscope.

© 2015 IEEE