CCD Multi-Ion Image Sensor with Four 128 × 128 Pixels Array

A semiconductor array pH image sensor consisting of four separated blocks was fabricated using charged coupled device (CCD) and complementary metal oxide semiconductor (CMOS) technologies. The sensing surface of one of the four blocks was Si₃N₄ and this block responded to H⁺. The surfaces of the other three blocks were respectively covered with cation sensitive membranes, which were separately printed with plasticized poly (vinyl chloride) solutions including Na⁺, K⁺, and Ca ionophores by using an ink-jet printing method. In addition, each block of the image sensor with 128 × 128 pixels could have a calibration curve generated in each independent measurement condition. The present sensor could measure the concentration image of four kinds of ions (H⁺, K⁺, Na , Ca ) simultaneously at 8.3 frames per second (fps) in separated regions on a chip.