Gas
sensing
Reliable gas sensing is important in
environmental, safety, process control and medical applications. There are several
possible markets for nanodot-based sensors:
Oxygen sensors
- Disposable portable gas sensors.
These are increasing in popularity, especially for subcontractors who require
low-cost sensors to fulfill statutory safety requirements. Oxygen
measurement in the 15-25% region could be rapidly exploited by several companies
- Combustion gas analysis. In applications
such as boiler systems, there is a need for oxygen sensors which can cope with
high temperature / high humidity environments, without the need for annual replacement
- Oxygen data-logging systems. These
could be used when shipping items which are sensitive to oxidation. A gas sensor
element priced at £2-3 would rapidly outsell the existing sensors, which
are typically priced at £15-20.
Hydrogen sensors
- Fuel cells are of increasing importance
as power generating systems, but their use of hydrogen presents hazards. Currently-available
hydrogen sensors are expensive, so a cheaper alternative should find
an expanding market
- Hydrogen-fuelled cars (powered
by fuel cells) are currently being developed by many automotive manufacturers.
Hydrogen sensors will be required at the point of delivery and several hydrogen
sensors on each car will be required when these are introduced over the next
decade. However, the best hydrogen sensor, developed by NASA, does not fulfill
the requirements of the automotive industry.
Nanodot sensors
The semiconductor sensors we aim to
produce should offer several advantages over electrochemical and solid-state metal
oxide gas sensors:
- Low cost and small size
- Superior performance at extremes
of temperature and humidity
- Long lifetime
- Low power consumption (compared
to metal oxide devices, which must be heated to 400-800 ºC)
- Lower cost packaging - the
metal oxide devices need packaging which can cope with the high operating temperature