March 31, 2009 The cost of securing large properties with physical barriers like fences or conventional electronic surveillance systems can be quite prohibitive but a new invention from Tel Aviv University promises to a cheap, effective solution in the form of a network of tiny sensors as small as dewdrops. Called "Smart Dew", the devices can be scattered outdoors on rocks, fence posts and doorways, or even indoors on the floor of a bank to serve as invisible security guards with each individual "dew droplet" capable of detecting an intrusion within a parameter of 50 meters (165 feet).

Prof. Yoram Shapira and his Tel Aviv University Faculty of Engineering team drew upon the space-age science of motes to develop the new security tool. Dozens, hundreds and even thousands of these Smart Dew sensors - each equipped with a controller and RF transmitter/receiver - can also be wirelessly networked to detect different conditions like the the difference between man, animal, car and truck, says Prof. Shapira.

Sounds could be picked up by a miniature microphone or the metal used in the construction of cars and tractors could be detected by a magnetic sensor. Smart Dew droplets could also be programmed to detect temperature changes, carbon monoxide emissions, vibrations or light.

Each droplet sends a radio signal to a "base station" that collects and analyzes the data. Like the signals sent out by cordless phones, RF is a safe, low-power solution, making the technology extremely cost-effective compared to other concepts, says Prof. Shapira."

The Smart Dew system is designed to be utilized on large farms or even the borders of nations where it's difficult, and sometimes impractical, to install fences or constantly patrol them. And at a cost of 25 cents per "droplet," Prof. Shapira says that his solution is the cheapest and the smartest on the market.

A part of the appeal of Smart Dew is its near-invisibility, Prof. Shapira says. "Smart Dew is a covert monitoring system. Because the sensors in the Smart Dew wireless network are so small, you would need bionic vision to notice them. There would be so many tiny droplets over the monitored area that it would be impossible to find each and every one."

David Greig

Via Tel Aviv University.