PRODUCT AND THEIR APPLICATION

Crocetin based microsensor for ethanol vapour sensing. This sensor can be used for the detection of ethanol in vapour phase, this sensor shows its promising application in the fermentation industries for the quality of their products and also in the forensic/police department for the spot detection of alcohol in the breath of an intoxicated driver.

DEMAND POTENTIAL

Alcohol vapour sensors will be of much use in the fermentation industry and in the forensic/police department. With the help of alcohol vapour sensor it will be possible to detect the stage of fermentation of a particular product.For the spot examination of suspected drunken driver,the alcohol vapour sensor wiil be useful.This sensor will detect promptly the presence of alcohol in the breath of the drunken driver.This will be simple/easier and it will not involve the service of a doctor (as required for other tests),it will be performed easily by policeman/forensic person.

The Export potential of this product is expected to be good.

MANUFACTURING PROCESS

The laboratory has developed a microsensor for ethanol using a coplanar multilayer structured device with a set of masks. These masks can easily be prepared by photo lithographic technique. The photo lithographic set up were not avialable, hence imported masks were used. .Two coplanar interdigited electrodes are vacuum deposited on an insulating surface sandwiching .

The sensitive biomaterial in ten layers.A silver or aluminiumControl electrode is deposited by vacuum evaporation technique on a insulating glass substrate through a mask.The glass slide is thorughly cleaned ultrasonically prior to use.The film of the senstive materilal crocetin whose area is defined by a second mask,it is deposited on the control electrode leaving an uncovered contact area.Particular thickness is maintained.Finally two interdigited electrodes are deposited by vacuum evaporation over the active material. This sensor is then annnealed under vacuum by applying several heat-cool cycles to ensure good inter particle and electrode-sensing material contact. This structure allows measurement to be made bith in the plane of the film(surface conduction) and perpendicular to the film.for gas sensing device surface conduction is more relevant than bulk conduction.In a simpler device only the inter digited electrode and the sensing material layers are deposited and current is measured in the plane of the film.

The total area of the sensor element is 2.5 mm * 2.5 mm.There are ten layers of sensing material sandwiched between the co-planar electrodes.The electrode width and the inter electrode seperation is 125 µm .