Things are Heating Up for Self-Assembling, 3-D Printed Bots

It's not quite transformers, but it's close. Two new studies have demonstrated an innovative design in which 3-D robots can automatically fold, shape and assemble themselves when exposed to heat.

Printable robots have long been a topic of research in the lab of Daniela Rus, the Andrew and Erna Viterbi Professor of Electrical Engineering and Computer Science at MIT.

Rus and her colleagues used heated sheets of a type of polymer known as polyvinyl chloride, or PVC, to make a two-dimensional sheet of material literally jump off the page and assemble itself into a 3-D machine.

These sheets of material were placed between two rigid polyester films that are full of slits.

"The PVC shrinks when heated and the slits eventually shut, pushing against each other and altering the shape of the PVC," according to Live Science. "This process bends the material into different shapes, based on the pattern of slits and how the heat interacts with the PVC."

But producing a pattern of slits that perfectly fold into one another is not as simple as folding origami.

"You're doing this really complicated global control that moves every edge in the system at the same time," Rus said in a statement. "You want to design those edges in such a way that the result of composing all these motions, which actually interfere with each other, leads to the correct geometric structure."

Shuhei Miyashita, a postdoctoral researcher at MIT, specially designed an aluminum-coated polyester sensor with an accordion-like shape that could be attached to the robots once they are fully assembled. It helps the robot to move and fold while pulsing electrical signals through the system.

The new studies build upon previous work done by Rus and fellow MIT professor Erik Demaine.

The findings were presented this week at the 2014 IEEE International Conference on Robotics and Automation in Hong Kong.