A big driver for the future directions of chemical sensing is the military. Funding agencies like the U.S. Defense Advanced Research Projects Agency (DARPA) have big dreams for what chemical sensing might be able to do for its armed forces. Imagine being able to put a sensor on the top of a tent in a war zone that can detect explosives or toxic gases 4 miles (6 kilometers) away.
Or picture a sensor that is so tiny, it can be embedded into fabrics. When the sensor detects a toxic agent, the color of the fabric changes, alerting soldiers to the presence of chemical toxins in the air. What about a sensor that could to alert soldiers to their dehydration levels? The implications for such technology would not only be the upper hand in battle, but also save potentially thousands of lives.
Chemicals also could be placed in airports to help stop terrorism by detecting minute concentrations of explosives without us having to undergo the extensive hassles of the security lines. In fact, scientists have already unveiled a sensor that can rapidly detect drugs and explosives close to 100 feet (30 meters) away with airports in mind [source: Engineering360]. These sensors could be installed at airport entrances and other places with large groups of people. Some types of chemical sensing devices can even be attached to cell phones to scan larger areas as law enforcement officials move around [source: Hsu].
Of course, chemical sensors don't only need to be used to divert nefarious activities. Detecting metals contaminants in water and possibly toxic chemicals in the air via sensors in security badges are just some of the ways that chemical sensing devices are changing our world.