Metal Oxide Semiconductor Sensors: Unrealized or Unrealizable Potential?
Having worked at the forefront of chemical sensing at University of Cambridge, and with a range of companies including Capteur Sensors, City Technology, MicroChemical Systems and Honeywell, our expertise is extensive and unmatched in
metal oxide semiconducting sensors
but we can also offer expert advice on sensing technologies related to
solid-state electrochemical
aqueous electrochemical
Through our network of associates we can provide a balanced portfolio, encompassing other established or emerging technologies such as
NDIR, UV, GasFET, Polymer, Pellister and SAW technologies
Metal Oxide Semiconductor Sensors:
Unrealized or Unrealizable Potential?
The technology has been available for over 30 years but has disappointed in fulfilling its potential. With its unmatched attributes of low-cost, miniature size, large detection range, ease of manufacture and CMOS compatibility, it has been steered towards large volume market opportunities. However to date, it has had few high volume market successes (automotive cabin air quality, gas bottle leak detection), while low-margin niche opportunities have accounted for the rest, particularly in detecting H2S in hot hazardous environments. With over 30 years of maturing, it should be capable of more than this!
One reason for this is that commercially available sensors employ SnO2 and to a lesser extent, WO3, as the gas-sensing material. While these n-type materials have advantages in terms of fabrication, ease of deposition and gas responsiveness, they are disadvantaged by issues such a drift, humidity interference and cross-sensitivity, and power consumption. Yet, suppliers still persist in using them and the more innovative, have addressed these shortcomings. Indeed, aligning the MOS sensor platform with a gas-sensitive material tailored for the specific application can meet the most demanding requirement. A strong materials development expertise allied to electronics skills makes the challenge almost straightforward. However, the disadvantages highlighted by early adopters have given the technology a reputation for unreliability.
The technology has not stood still, and the new battleground lies in hammering down power consumption, as new opportunities open up. Putting a MOS layer on top of a silicon chip extends the reach of the technology. The old approach of a discrete heated sensor with one signal output may soon be displaced by multiple sensors with multiple signal interrogation methods. This gives MOS a distinctive advantage over alternative competing technologies.
Having worked at the forefront of chemical sensing at University of Cambridge, and with a range of companies including Capteur Sensors, City Technology, MicroChemical Systems and Honeywell, our expertise is extensive and unmatched in
