Being able to print out a functional robot is a beautiful dream of cheap, accessible robotics for everyone. And right now, it's impossible.
But we're making progress fast. A few years ago, we took a look at a project from MIT, Harvard, and the University of Pennsylvania that was developing soft robots with flexible, printed circuits. Last year, we met a robot that could be printed out flat, fold itself up, and then crawl around with the addition of a motor and battery.
And this year at the IEEE International Conference on Robotics and Automation (ICRA), Harvard researchers demonstrated a proof-of-concept lamp that can be printed out, folds itself, and includes both a mechanical switch and a capacitive touch sensor.
The sensors are the big news here: they come straight out of the printer, just like the structure of the lamp itself as well as all of the self-folding elements and most of the wiring.
The mechanical switch is a hinged four-bar linkage that can be repeatedly twisted (hundreds of times) to open or close printed electrical contacts. The touch sensor (which can capacitively sense applied force) can be used to switch the lamp on and off, or to adjust the brightness of the LED.
The thing that comes out of the printer (it's a rather special sort of printer) is a flat multi-layer sandwich of shape-memory polymers (they take care of the actual folding, triggered by heat), thin layers of copper, layers of paper and foam for structure, and double-sided tape to keep it all stuck together.
Obviously, not every single part of this lamp was printed. Discrete components like the LED were manually soldered to the composite before folding, and the lamp was wired into an Arduino to get the capacitive touch sensor to properly control the LED.
But this is partially because the focus of this research is getting the printed sensors to work, and as the researchers say in the paper, it was a necessary goal to achieve that will enable the next generation of printed electronics (and robots):
The self-assembling lamp demonstrates the potential for the rapid and inexpensive production of self-folding machines that can interact with the environment. It showed that even complex mechanisms, such as the mechanical switch, can be integrated into the self-folding process of a larger machine, and utilized in practical electronic circuits. Although printable sensors may lack the robust structural strength and reliability of other sensors, they have many potential applications such as low-cost rapid prototyping and manufacturing of customized designs in residential homes. The development of sensors that utilize self-folding manufacturing techniques and their integration into more complex structures is an important stepping stone in the path towards autonomously assembling machines and robots.
"Self-assembling Sensors for Printable Machines," by ByungHyun Shin, Samuel M. Felton, Michael T. Tolley, and Robert J. Wood from the Wyss Institute for Biologically Inspired Engineering at Harvard University, was presented on Tuesday at ICRA 2014 in Hong Kong.