Fig. 1.

Concept of intracellular action potential recording using an OECT matrix supported by electroporation. (A) Top-view photograph of a 4 × 4 OECT matrix generated by merging microscopic images. Each channel (size: 5 × 5 μm², red circle) is placed at a 2-mm spacing. The outer line is a sample for a test run. (Scale bar, 2 mm.) (B) hiPSC cardiomyocytes cultivated on a channel (size: 300 × 300 μm²). (Scale bar, 100 μm.) (C) Schematic illustration of the structure and circuit configuration of an OECT where cells are cultured. (D and E) Illustration of the signals recorded by OECT supplied with a DC drain voltage (D) and pulse drain voltage (E). On applying a pulse drain voltage, a high-frequency component flows from the drain to the reference electrode causing electroporation, and thus the intracellular action potential is recorded.