IEEE Robotics & Automation Magazine - September 2010 - 53

and then using self-disassembly to remove
the extra modules to form a specific shape.

light and compact and that configures
itself into a desired form at fine granularity. Our current system functions as a
Summary and Future Outlook
Smart Pebbles system. There is a suite of
interesting challenges that have to be
We have presented a detailed retrospecovercome to reduce the size of this systive on modular robots and discussed contem further from 1-cm scale to 1-mm
nections between modular robots and
scale and realize the dream of Smart Sand.
programmable matter. This field has seen
New technology will have to be devela great deal of creativity and innovation at
oped to package computation, sensing,
the level of designing physical systems
actuation, communication, and power in
capable of matching shape to function and
a 1-mm scale module. New fabrication
algorithms that achieve this capability.
technology will have to be developed to
The success of these projects rests on the
fabricate such models rapidly and in costconvergence of innovation in hardware Figure 17. A initial 3 3 5 block of
effective ways. New supporting algorithms
design and materials for creating the basic modules was used to form this
that are scalable and matched to the propbuilding blocks, information distribution 60-mm-tall humanoid through the
erties of the hardware would have to be
for programming the interaction between self-disassembly process.
the blocks, and control. Most current systems have dimensions put in place. Ultimately, these advances will lead to the creation
on the order of centimeters, yet pack computation, communi- of desktop-scale 3-D fabrication technology of electrically and
cation, sensing, and power transfer capabilities into their form mechanically active recyclable parts for everyday users.
factors. Additionally, these modules operate using distributed algorithms that use a modules ability to observe its current neighbor- Acknowledgments
This work is supported by the Defense Advanced Research
hood and local rules to decide what to do next.
Within this broad space, our own work spans the develop- Projects Agency (DARPA) Programmable Matter and Chemment of several modular self-reconfiguring robot systems. bots programs (Dr. Mitch Zakin, PM) and the U.S. Army
Building on this experience, we identified self-disassembly as a Research Office under grant numbers W911NF-08-1-0228
way of creating shapes out of smart components using a and W911NF-08-C-0060, National Science Foundation (NSF)
subtractive process. The key idea is to create a bag of smart Emerging Frontiers in Research and Innovation (EFRI), Intel,
components that can program their connections in an autono- and the National Defense Science and Engineering Graduate
mous way to organize different shapes. This simplifies the (NDSEG) fellowship program. We also thank Prof. Rob Wood
mechanics of shape creation by eliminating the need for actively and Dr. Ara Knaian.
moving parts. The required actuation mechanism (disconnection) is generally easier, faster, and more robust than actively Keywords
seeking and making connections. The trade-off is two-fold. Modular robots, self-assembling robots, self-disassembling robots,
First, self-disassembling systems must start from a preassembled metamorphic robots.
structure of modules. Second, external forces must be employed
to remove unwanted material from the system. Often, these References
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that can function analogous to a bag of Smart Sand that will be
SEPTEMBER 2010

IEEE Robotics & Automation Magazine

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