The object can be classified in a handful of ways. Most basically, it's a limb — an arm to be specific. It's orange and made of plastic. It sits in the palm of its designer's hand and has industrial sensibilities that make it look almost robotic. Functionally, it's mostly inert, unless accompanied by the rest of the figure's anatomy. And scientifically, it's the first object ever constructed from thought alone.

Ironically, the orange hand, which was built by the Chilean-based start-up, Thinker Thing, was made totally hands-free. The product's designer, George Laskowsky, who works as the company's Chief Technical Officer, didn't click the mouse once during construction.

The scientific breakthrough happened quietly one day last month in the country's capital city, at a design studio called Santiago MakerSpace.

The technology for 3D printing has existed for two decades, but only recently have companies begun pitching consumers desktop models for in-home use. The response has been lukewarm. Designers can enjoy greater freedom in how they create products; meanwhile, the lay-person can't make a single thing on his or her own.

"What is the point of these printers if my son cannot design his own toy?" Bryan Salt, CEO of Thinker Thing, told the BBC. "I realized that while there were a lot of people talking about the hardware of the printer no one really seemed to be talking about how to actually use it."

Thinker Thing wants to change that. Or rather, it wants you to change that.

The designers call it the Monster Dreamer Project. It's a computer program, powered by Emotional Evolutionary Design (EED) that gives a user the opportunity to choose from pre-selected design parts and construct the entire creature using only the user's brain. The Project debuts at the end of June in schools throughout Chile.

Like a miniature call center, each student will don an Emotiv EPOC headset while using the program. The headset, a $300 electroencephalography (EEG) device, contains 14 sensors that sit on the user's head and pick up electrical impulses from the brain. Students will be presented with pre-determined shapes that change in size according to the levels of boredom or excitement picked up by the EEG. Once the student completes this process for each body part, the program then assembles each part into a fully-formed model that is ready for printing.

If the whole thing seems too good to be true, be at ease. The scope of EED technology is extremely limited — maybe only to small figurines whose parts get lost between couch cushions. But like any scientific breakthrough, small steps can lead to huge advances.

Consider what's taking place at the Creative Machines Lab at Cornell University, where a team of researchers is also trying to evolve 3D models with the mind. People aren't as good at imagining something from nothing as they are at critiquing what already exists, the lab realized, so it created EndlessForms, a website that lets users build large, complex structures from 15 pre-existing shapes.

"If you wanted to make a cat, you might click on one shape with the semblance of a muzzle and another with two pointed, ear-like triangles on top," the BBC reports. "The computer would then offer up a series of new shapes that more closely resemble the cat you have in mind, and so on until the model reaches the desired shape."

Eventually, the lab reached the same conclusion as Thinker Thing: endless mouse-clicking quickly gets old. So they collected several Emotiv EPOC headsets and began working on the process of transmitting these shapes through pure cognition. The director of the lab, Professor Hod Lipson, said they ran into problems right away.

"At some point we were thinking it was only measuring the level of sweat," he said, "because we were actually trying so hard to feel happy or sad about something." In the end, the headsets didn't produce any 3D models, just frustration. The team eventually made use of eyeball-tracking devices and soon concluded that, while rigorous in its exercise, tracking eye movement offers no information regarding emotions: is the person looking at the object because he finds it beautiful or because he finds it hideous?

Even with the apparent simplicity of Lipson's design program, some experts say anything demanding more than a "yes" or "no" asks too much of an EEG.

"If they are simple positive or negative emotions, it can be 100%," said Dr. Olga Sourina, head of the Cognitive Human Computer Interaction Lab at the Nanyang Technological University, Singapore. "When you need to differ between more emotions like anger or fear, they can be less accurate."

Far more accurate in measuring brain activity, namely preferences and emotions, is magnetic resonance imaging, or MRI. Although typically used in radiology to visualize internal structures of the body, such as when X-rays fail to suffice, MRI scans have also been used in studies to map areas of the brain while people are dreaming. Scientists find faith in these studies, which offer hopeful glances into decoding a person's abstract mental images and reproducing them as tangible, 3D models.

Consumers should not see MRI as a feasible alternative to EEG in the quest for 3D printing, said Professor Jack Gallant of the University of California, Berkeley and head of the research team in MRI dream decoding. "As a giant three million dollar magnet, it is not something you would just wear around," he says.

For now, Thinker Thing is happy to be engaged in the exploration of 3D printing in any capacity. The prospect of creating a product with nothing but your thoughts doesn't strike CEO Bryan Salt as particularly urgent.

"I have been doing 3D modeling since it began back in the 80s," he said. "And the process is that you build something and then you move it about. You do not sit down and think, 'I have something absolutely finite in my head and that is what I am going to build.'"

Elsewhere in the company, George Laskowsky marvels at the tiny orange arm he holds in the palm of his hand. "It is really something magical to be there, sat without moving a limb, and watching the designs evolve into something that you were thinking about."