Take a moment and envision an electromagnet: a simple coiled wire driven by a hefty electrical current gives a fully-programmable magnetic field strength (on, off, and everything between).  Electromagnets are ubiquitous, but it turns out that there is a little-known device with similar functionality yet zero static power consumption -- they are called electropermanent magnets, and they've been around and in use since the 1960's!  A 2010 PhD thesis by MIT Media Lab's Ara Knaian examines the physics, scaling, trade-offs, and several new actuator designs (eg. stepper motors) using these little-known wonders.  Recently, electropermanent magnets facilitated an innovation in "programmable matter," where they were instrumental in creating the world's smallest self-contained modular robots to date (12mm/side).  Read on for details about this fascinating technology, along with discussions about existing and possible robotic applications.

I finally took a few minutes to watch a tear-down of the Roomba 4000 Series vacuum cleaner by Dino Segovis of DinoFab.com.  The 20-minute two-part video (embedded below) provides a pretty solid look at the design considerations that went into making the Roomba both robust and low-cost.  While the sensors and motherboard are definitely interesting, the motors are the most intriguing to me -- they seem to be separately fabricated modules with a small DC motor coupled to a planetary gearhead via a belt drive.   It is also striking just how much gunk (hair, dust, etc.) builds up inside every nook and cranny of the robot.  Definitely a hacker-friendly robot that offers plenty of lessons to people interested in designing commercial robots -- almost worth buying one just to look at first-hand.

Unmanned aerial vehicles (UAVs) are no longer relegated to military and police forces.  Amateurs and hobbyists, working in close-knit online communities, are fusing old RC airplane concepts with modern technology to create UAVs that rival commercial offerings.  Recent efforts suggest that an amateur UAV, complete with on-board cameras, wireless video downlinks, operator heads-up display, autonomous waypoint navigation / autopilot control, and ground tracking stations can all be had for less than $2,000 (read on for details)!  Unfortunately, the FAA (aviation regulatory body in the United States) already treats commercial UAVs as regular planes, requiring aircraft registration and 60 day pre-flight plans.  While the regulations for hobbyists seem to be more lax, I personally believe the FAA should embrace amateur UAV builders in the same way that the FCC embraced ham radio operators of yesteryear.

Autonomously seeking out power for battery recharging is a pretty crucial capability for advanced mobile robots.  While Roomba-like docking stations are a quick fix, "plugging in" to existing infrastructures is preferable.  Not long ago, the robotics world was abuzz with the Willow Garage Milestone 2, where (among other things) a PR-2 robot plugged itself into 9 different wall outlets.  My curiosity on this subject was further piqued when I saw Intel's Marvin robot use electric fields emanating from an outlet's internal wiring to finely localize an outlet/plug and adeptly plug itself in, all sans camera.  I'd like to share some photos and videos of recent efforts (by both the Willow and Intel folks), as well as examine the history of robots plugging themselves into wall outlets.