Electrode robustness in artificial cerebrospinal fluid for dielectrophoresis-based LoC

In this paper, we present hybrid microelectronics / microfluidic Lab-on-Chip (LoC) platform intended for implantable medical microsystems for neurotransmitter detection. In vitro experiments were achieved using artificial cerebrospinal fluid (ACSF) from Tocris Bioscience where microspheres were immersed to test the behaviour of the designed LoC. One of main features of the proposed LoC platform is its thin thickness, including micro-channels and silicon CMOS chip. The latter is integrated into the glass top-layer of the LoC measuring 0.5 mm. The size of the device is 9 mm × 5 mm. the electrode architecture is composed of 8×2×2 L-shaped electrodes in a 650 μm channel width and 4 sites for interdigitited electrodes. 32 L-shaped electrodes were connected to a electronics circuit for cells manipulation using dielectrophoresis (DEP). The described LoC achieved an efficient separation within a concentration of 50 μl of a solution of microspheres, distilled water (DW) and 500 μl of ACSF. Beyond this concentration, electrode destruction was observed.