Our Sensor Technology

RoboScientific instruments can be fitted with a variety of sensors with several conventional types for measuring inorganic gases and our own designs of organic semiconductor sensors for detecting VOCs.

Silica Substrate Sensors

The operation of organic semiconducting sensors working at room temperature seems to be quite simple in principle but in practice it is much more complex and is not completely understood by most workers in the field. These sensors comprise a substrate, such as silicon, a pair of gold-plated electrodes, and a semiconducting organic compound as the sensing element. The semiconducting film is deposited between the two electrodes. Specific volatiles cause the film to swell, and thus change the electron mobility within the coating so changing the measured impedance between the electrodes.

Over the past three years RoboScientific has undertaken extensive work in the development of sensors both in the choice of semiconducting materials and in the methods of stimulating the sensors to improve upon the responses to give benefits both in selectivity and in sensitivity. This work has led to the filing of three new patents.

 
Printed Plastic Sensors

Our latest sensor designs use a plastic film upon which are printed a variety of electrode patterns using conductive inks. These electrodes are then coated with a defined thickness of a semiconducting compound to create the complete sensor. These new electrodes have two significant advantages over our existing designs. First their cost is much lower that that of devices based upon the silica/gold substrate and second the temperature coefficient of the plastic film base is similar to that of the semi-conducting coating so both parts expand or contract at a similar rate giving much better temperature stability.