Single-Chip Chemical and Biological Sensors
Detection of very small amount of chemical and biological agents had been an active area of research for many years. From carbon monoxide detection for environmental applications to biological and biomedical monitoring, missile fuel leakage detection and security applications require high-sensitivity sensors that can measure low parts per billion (ppb) or part per million (ppm) of chemical or biological agents. Recent development of microelectronic technology has provided a good opportunity for fabrication of sensor and the interface circuit on a single chip. Single-chip fabrication of the sensor and the interface circuit provides higher-resolution, better accuracy, and lower-noise signal conditioning and amplification. In addition, better control over the sensor operating condition such as temperature and linearity can be provided. When the sensor is close to the interface circuit, higher sensitivity and lower noise can be achieved by omitting long wire capacitance and electromagnetic interface. The array of sensors can be built on a single chip for minimizing false alarms and selectivity of the sensor.