The Grand Challenge involves both ground and airborne designs
The Ministry of Defence is holding a competition to try to find the spy technology of the future.
The inventions are being tested at a specially-built village on Salisbury Plain and UK designers from education and business have been putting their machines through their paces.
It's hoped the winning entry will indentify hidden threats and save the lives of British soldiers serving in conflict zones across the world.
The biggest dangers for our Armed Forces are usually the ones they cannot see.
Major Matt Kelly, an expert in urban combat, said: "On a daily basis (troops) are being shot at by snipers.
"There are guys with IEDs (improvised explosive devices) and suicide bombers... if we had technology to see through that wall or into that building we could have seen him."
Ground and air
Max Pengelly from Team Locust has designed a mini 'spy plane'
Eleven teams have reached the final of the MoD Grand Challenge and have names like Locust, Stellar and Swarm.
The inventions are a mix of ground and air-based vehicles.
Max Pengelly, from Team Locust, said their design is essentially a mini-spy plane: "It's got a lot of capability inside it - it's got a camera, a radio control system.
"So what you'll be able to do is fly your paper plane over a village and see who's there."
Designer Raglan Tribe's robot has cameras and heat sensors to spot danger and take some of the risk away from troops.
Raglan Tribe's robot has camera and a heat sensor
He said: "This is basically doing the dirty work, going in beforehand, lurking in the right places, seeing what's going on... where the lines of fire are and so on, so they can approach more safely."
The last task in the competition, which runs from 16-18 August , will give surviving teams one hour to send their systems into the village.
They'll have to find a range of threats which include specially planted realistic props, as well as actors.
Whichever of the 11 teams finds most dangers will get the chance of an MoD contract and could see their invention in action in places like Iraq or Afghanistan.