The military employs military working dogs in bomb detection. Therefore, working dogs can help us avoid mines and improvised explosive devices, and detecting the female suicide bombers currently in vogue in Iraq. However, the dogs are not effective in OIF and OEF because it is too dry over there.
A dog's nose is a mucous membrane with sensors all over. The sensors bind to the scent particles in the air through the mucous membrane. If the nose dries out, the sensors are not as effective in binding to the scent molecules. Because the air is so dry in Iraq and Afghanistan, it dries out dog noses rapidly. The bomb detection dogs were only effective for much less than one hour before needing to take a break and re-wet their noses.
When I was deployed, I wrote up a proposal to build a humidifier for a working dog, to extend his working time. To accomplish this, you can take a spritzer to spray water onto his nose directly, for a low tech method, interim capability.
My design was: Mount the spritzer by the dog's head, and aim it to a point 3 inches in front of his nose. The spritzer would automatically spray water toward this point periodically, to moisturize the air as he breathes in. The exact configuration and timing will require experimentation, for which I did not have the money, personnel, nor assets to do.
Alternatively, we can spray moisturized air, instead of water spray, into the air. This might be more effective, but it would also be more complex.
Anyway, I submitted the proposal to the local counter-IED working group. They forwarded it to some people in the K-9 community. And I never heard back from them again. Story of my life, eh? :)
This proposal will make a great college/backyard engineering project if you want to build it. All you need is a dog, some dry weather, and some time to tinker with. It is not technically sophisticated, but you do need to program that motor controller.
So that is another one of my engineering ideas as I was sitting in the Fallujah contracting office doing paperwork. We need to get more working dogs into the military because they are so useful. In Vietnam, soldiers used to patrol the jungle with working dogs. The dogs could smell and hear the boobytraps, and were great sentries at night. Dogs also are good at reading body language and help us separate good guys from bad guys. In the new population-centric warfare we are fighting, working dogs are a crucial tool that we are not using effectively.