bots IN BRIEF
16 SERVO 02.2017
Working on the ChainFORM Gang
As sensors, computers, actuators, and batteries decrease in size and increase in efficiency, it becomes
possible to make robots much smaller without sacrificing
a whole lot of capability. There’s a lower limit on
usefulness, however, if you’re making a robot that needs
to interact with humans or human-scale objects. You can
continue to leverage shrinking components if you make
robots that are modular; in other words, big robots that
are made up of lots of little robots.
MIT’s ChainFORM is an interesting take on this idea.
It’s an evolution of the LineFORM multifunctional snake
robot that introduces modularity to the system, letting
you tear off a strip of exactly how much robot you need, and then reconfigure it
to do all kinds of things.
MIT Media Lab calls ChainFORM a “shape changing interface” because it
comes from their Tangible Media Group. (If it had come from a robotics group, it
would have been called a “poke-able modular snake robot with blinky lights.”)
Each ChainFORM module includes touch detection on multiple surfaces, angular
detection, blinky lights, and motor actuation via a single servo motor. The trickiest
part is the communication architecture.
MIT had to invent something that can automatically determine how many
modules there are and how the modules are connected to each other, while
preserving the capability for real time input and output. Since the relative position
and orientation of each module is known at all times, you can do cool things like
make a dynamically reconfigurable display that will continue to function (or
adaptively change its function) even as you change the shape of the modules.
ChainFORM is not totally modular in the sense that each module is not
completely self-contained at this point. It’s tethered for power, and for overall control there’s a master
board that interfaces with a computer over USB. The power tether also imposes a limit on the total
number of modules that you can use at once because of the resistance of the connectors: no more than
32, unless you also connect power from the other end.
The modules are still powerful,
though. Each can exert 0.8 kg/cm of
torque, which is enough to move small
things. It won’t move your limbs, but
you’ll feel it trying, which makes it
effective for haptic feedback applications,
and able to support (and move) much of
its own weight.
The LineFORM as a lamp.