Oxford Nanopore has developed custom high-performance, low-cost Application Specific Integrated Circuits (ASICs) for the GridION system. 
These ASICs apply biased potentials across each nanopore in the sensor array chip and measure the resulting ionic current flow. They are contained within the single-use cartridge.
These ASICs have been designed to measure current at very high sampling frequencies, tens of kHz per nanopore, while minimizing measurement noise and maximising signal. Each ASIC contains a high density array of low-noise amplifier circuitry, and can be scaled to measure from tens to thousands of channels, with further projects underway for larger chips. More than one ASIC may be included in each cartridge for higher-throughput systems.
graphic: ASICS mounted on a PCB, which are linked to a sensor array chip. As many ASICs may be included in a single GridION cartridge or MinION as are required.