Posted by: Footler PJ4 SEP 2008
A dog’s ability to detect smells is, we are told, up to 10,000 times better than ours. Thus dogs are trained to sniff out drugs and explosives and to find people buried under rubble or snow. But training them takes time and resources. They may have off-days, become ill or make mistakes. And they have to be fed, rested and exercised.
During the past decade several attempts have been made to replicate or improve the dog’s ability using electronic technology. A team at Massachusetts Institute of Technology is working on a tiny ceramic nose to detect hazardous gases such as carbon monoxide.
Nearby, at Tufts University, researcher are using strands of dried DNA to identify different scents. The Coca-Cola Company has a machine to evaluate corn syrup and Nestlé has one to check coffee aromas. Some attempts have also been made to formulate perfumes using electronic noses.
A new threat to the friendly, tail-wagging canine snuffling around your luggage at the airport comes from a grant of about US$1m awarded to a team at the University of California, Riverside. They are seeking to devise a small, reliable, hand-held device that can screen baggage and people and also have military applications such as finding landmines and explosives.
The team intends to capture gas molecules using an ultra-thin film of zeolite interfaced with a sensor. This will generate a specific fingerprint for different compounds, which can be identified by computer software.
Zeolites are commonly used aluminosilicate minerals with many and varied applications. They have a regular pore structure and are often termed “molecular sieves”. Synthetic zeolites have some advantages over the natural forms. The raw materials, principally silica and alumina, are abundant and a uniform product can be made.
Zeolites are used in the water purification and petrochemical industries as well as being a part of reprocessing treatment in the nuclear industry. They have been used in agriculture, in construction, as a filter additive in aquariums, in cat litter and even as gemstones.
So there you have it — a cheap, abundant raw material, lots of money to develop the system, little further training required to operate it all day every day and no need for feed or exercise or veterinary care. However, I still think I will miss the dog.