The 250 kilometer demilitarized zone between South and North Korea, despite its name, is the most heavily militarized border in the world.
On the South Korean side, there is one guard post every 50 meters, two guards per post and twelve shifts per day. With about 5,000 guard posts, in theory, there are 120,000 man-years spent on guard duty each year.
Now, to support the South Korean troops along the demilitarized zone and guard key military installations, a subsidiary of Samsung has developed a sentry robot that they call the SGR-A1.
The heat, motion, voice detecting and weapon carrying robot has the ability to detect the invasion, give warning and fire at intruders.
The two armed robots with surveillance, tracking, firing and voice recognition systems have already joined their human counterparts out on the field. These robots can stand guard continuously for years without a break.
This $200,000, all weather, 5.56 mm robotic machine gun also sports a 40mm grenade launcher. Controlled from a remote command center, it can identify and shoot a target automatically from over two miles (3.2 km) away.