Figure 2.

(A) Hybrid integration of the sensor chips in a milled opening in the bottom of a cell culture flask. A metallic holder was brought inside the flask and fixed with magnets from outside (1). The flask was flipped, sensor chips were positioned in a opening milled into the bottom, and UV-curable adhesive was applied (2). After curing, the magnets were removed and the holder released through the neck of the flask resulting in a positioned chip with its surface in-plane with the flask surface (3); (B) Schematic representation of the cell layer. Cells are supposed to settle on the flask and chip surface but not on the hydrogel membranes covering the sensor electrodes.