Figure 1
From: An organ-on-chip device with integrated charge sensors and recording microelectrodes
Schematic of the proposed OoC device with integrated multi-modal sensing. (a) Sketch of the frontside. Pink arrows indicate electrical connections for floating-gate FETs used to monitor pH changes, as well as extension of the floating-gates used as microelectrodes for recording activity from electrically active cells. (b) Sketch of the backside. Electrodes are fabricated on the frontside and the polymer membrane is released by etching silicon from the backside, leading to a well-like structure to house the analyte-under-test. (c) Sketch of one sensor with labeled terminals. (d) Schematic of the equivalent circuit of the device when used as FG-FET. Capacitances due to the electric double layer are shown as \(C_S\) and \(C_A\) at the sensing area. (e) Schematic of the working principle of the FG-FET. When there is a change in the net charge in close proximity to the FG extension, the working point of the sensor will change. This change can be detected by monitoring the drain current of the transistor.
