ISFET technology for multi-sensor technology: from lab-in-a-pill to massively parallel measurements

Laboratory-in-a-pill, or capsule endoscopy, became a reality almost as soon as the invention of the transistor enabled miniaturisation of circuits into a small enough device. Of the many possible sensor modalities pH has emerged as an important measurand for diagnostics and laboratory analysis. Presented is the background to the early instances of the technology, including a summary of the published work on pill-based diagnostic devices. Then, how concepts from pill technology have led to further sensor integration, and to sensor system on chip (SSOC) in particular is presented. To conclude, consideration is given to how many ISFETs have been integrated using SSOC technology, and how this technology has led to the development of post-light gene sequencing systems using CMOS.