FORTUNE -- Venture capitalist Brad Feld is best known for his early bets on Internet companies, like Cheezburger, Feedburner (acquired by GOOG) and Zynga (znga). But a lot of his attention these days is being consumed by robotics, which he likes to refer to as "software in plastic."
The latest example is Modular Robotics, maker of a robot construction kit for children. Here is how the company describes its product, called Cubelets:
Cubelets are magnetic blocks that can be snapped together to make an endless variety of robots with no programming and no wires. You can build robots that drive around on a tabletop, respond to light, sound, and temperature, and have surprisingly lifelike behavior. But instead of programming that behavior, you snap the cubelets together and watch the behavior emerge like with a flock of birds or a swarm of bees.
In other words, it's a much more evolved version of the basic electronics or circuit-board kids a lot of us played with as kids.
Modular Robotics is third robotics company that Feld has invested in via his Boulder, Colo.-based VC firm, Foundry Group. The first was Orbotix, maker of a smartphone-controlled gaming ball. After that was 3D printer company MakerBot Studios, which basically lets you create or replicate just about any design.
MakerBot is based in Brooklyn, but both Modular Robotics and Orbotix are based in Boulder -- where Feld is helping to create a small robotics ecosystem. Not only through investments, but also by recently launching a meet-up series called Boulder is for Robotics, which Feld views as a distant cousin to the Homebrew Computer Club that ultimately spawned Apple Computer (aapl). From a Feld blog post back in February:
Let’s consider how Steve Wozniak developed the Apple computer, which revolutionized the computer industry from a garage. Did he really create a computer from scratch, transistor by transistor? Or did he emerge from hundreds of tinkerers that relied on a large community that provided mail-order electronic kits, do-it-your-self magazines, inspirational people, and hundreds of man years of university research? The bay area was indeed the place to be at the time with the Homebrew Computer Club and marketing genius Steve Jobs who convinced Wozniak to sell his design, laying the foundation for Apple. Building robots is much more complex than building computers, however: robots consist not only of computers, but also of sensors and mechanisms that need to be invented, re-combined, and modified to create a compelling product. I therefore believe that being part of a community is even more important for developing successful robot companies and having all the tools, know-how, and manpower close by provides a unique competitive advantage.
Feld adds that Boulder is particularly well situated for such a cluster, given its proximity to affordable PCB manufacturing and board assembly hub Aurora.
As for Modular Robotics, Feld says that the $3 million investment -- led by Foundry, with Bullet Time Ventures also participating -- was borne of people he'd met through Boulder's burgeoning robotics community, and from themes that had spring from it:
"I'm completely fascinated by 'software wrapped in plastic'" Feld says. "On top of this is an incredible community that grows around this (for MakerBot it's Thingiverse, for Orbotix and Sifteo it's other apps being built on their platform) and ModRobotics was a perfect example."
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