Surface sensor

ChipSensors, a fabless semiconductor start-up company, has developed a sensor that uses the surface of an integrated circuit to sense parameters such as temperature, humidity, certain gases and pathogens.

The company's patent-pending technology exploits the fact that the dielectric material in standard sub-micron CMOS comprises porous oxides and polymers. By selectively admitting or blocking ingress of the agent to be sensed, any resulting changes in electrical characteristics can be accurately detected and measured.

The sensor technology was shown  for the first time last week at the RFID Europe 2007 exhibition in Cambridge. Visitors to the company's booth saw a working demonstration of a prototype single-chip temperature and humidity sensor, communicating via an off-chip wireless link to a laptop PC displaying real-time measurements.

The 0.13µm sensor chip shown has obvious applications as an all-electronic replacement for the type of electromechanical thermostats and humidistats used in building management and environmental monitoring systems. ChipSensors is also currently developing an ultra-low-power wireless version of this sensor - which integrates all the signal conditioning, microcontroller, memory and RF transceiver functions onto the same chip as the sensor itself - for incorporation into passive and active ID tags.