Maybe we haven't reached the point where Skynet becomes self-aware, but we're blithely stepping into the brave new world of Terminator 3: Rise of the Machines, where humans are superfluous. iRobot (IRBT 0.58%), perhaps best known as the maker of robotic vacuums, has filed a patent for a 3-D printer that can print out and assemble a robot without the need for human interaction. All we need is Arnold Schwarzenegger's voice intoning, "I'll be back."

Safety in numbers
Additive manufacturing, or 3-D printing, as it's more commonly called, has come a long way since the first concepts were patented in the mid-1980s, reached a tipping point, and became mainstream with companies like Boeing producing tens of thousands of 3-D printed parts for its military customers. With General Electric anticipating up to half the parts in its wind turbines and engines could be 3-D printed within the next decade, analysts expect 3-D printing to grow into a $3 billion industry by 2016 and expand to almost $7 billion by 2019, with parts production accounting for 80% of industry revenues.

Where 3-D Systems (DDD -1.15%) and Stratasys (SSYS -1.11%) are the titans who've doubled the sales of printers since 2005, open-source printer developers like RepRap, Ultimaker, and MakerBot are challenging the corporate business model and bringing the technology to the masses. Interestingly, RepRap may have anticipated the leap iRobot made by designing a 3-D printer that encourages users to print out parts to assemble other RepRap printers. iRobot simply went it one better by eliminating the need for people to do the finishing work and assembly.

Desire is irrelevant. I am a machine.
Of course, a patent isn't a product, so we haven't become completely superfluous yet, but the lines are blurring between where humans end and robots begin. With the advent of the industrial revolution, people have always humanized their machines, giving planes, trains, and automobiles human names. As iRobot's advertising suggests, people identify with their Roombas, too.

When they take on more of a human form, we won't be able to help but feel that they're sentient beings. This Japanese robot, designed to offer comfort to those in need, provides an unsettling sense of the uncanny:

iRobot, along with its partner Raytheon, have advanced the technology as its "robot fabricator" patent covers an all-in-one design incorporating a 3-D printer and two arms to do all the post-production work and assembly.

It was something of a joke where it was believed the 3-D printing industry would cease to exist once printers could print out copies of themselves. Yet it was also simultaneously assumed that because the parts printed were static -- printers do require moving parts, after all -- it couldn't happen. At the very least, we humans would have to put it together. iRobot says, nuh-uh, that's not necessary either.

iRobot, do you?
Considering iRobot's product portfolio, it's not all that surprising. The Roomba may be the public face of the robot maker, but all along it has been developing machines that displace the need for human intervention. Typically it's for jobs that are dirty, difficult, or dangerous for individuals, like its small unmanned ground tactical mobile robot to spy out dangerous situations or its PakBot, which performs bomb disposal duties.

Military spending is a fickle source, though, and the 5% increase in iRobot's quarterly sales was as a result of an 83% surge in the domestic home robot division and a 16% rise in international sales. Military robot sales actually fell 37% in the quarter. It may soon need to add a robots-making-robots segment, though how soon they'll replace the executives in the front office remains to be seen.

Technology has always led to progress and the creation of more jobs. When horse-and-buggy manufacturers were displaced, automobile makers ended up hiring more workers than the obsolete industry ever could. But when machines start replicating themselves and obviating the need for workers at all, we move to a point where we're all obsolete.