Robotics can be a tricky subject to teach children, and it's hard to know where to start. Cubelets is a system of modular cubes that each have one use, interaction, or behavior, and by linking them together you can create easy to understand robots with impressive behavior. It's a great concept: you start with very basic ideas, and then by linking them together you can create something that can work in a variety of ways.

"Cubelets was originally called roBlocks and was a project I worked on while in grad school for architecture at Carnegie Mellon University in Pittsburgh," Eric Schweikardt, the creator of Cubelets, told Ars. He wanted a way to let people interact with digital models, and thought blocks was a good beginning. "I started to add more functionality into the different cubes and Cubelets evolved out of that. I never intended to make and sell a product, but after the 20th lab visitor asked when they could buy them, I started to warm to the idea." Smart move: the first batch of 100 beta kits has already sold out.

Each $300 kit comes with 20 blocks, and they're classified as either action, sense, or utility. The official site has some information on how they can be used, as well as a brief demonstration video. "If you make a simple robot by connecting a Light Sensor block to a Speaker block, they'll start to talk, and when the light in the room gets brighter, the Speaker will get louder." Each robot requires the battery block for power, and you can continue adding from there. "Next, you could swap the Speaker for a Drive block, and when the light gets brighter, the robot will drive faster," Schweikardt continued. "Maybe you'd want to put an Inverse block in between the Light Sensor and Drive blocks. Then the robot would drive slower as the light gets brighter."

It sounds simple, but the 20 blocks allow for a variety of behaviors and experimentation.

"The neat thing about Cubelets is that while each of the individual blocks is easy to understand, when you snap a few of them together, the robot can behave in rather astonishing ways," Schweikardt told Ars. "Since the blocks are responding to real-world sensor input, their behavior can be remarkably responsive and lifelike. It's easy to put together robots that behave like animals—and that's led a few people to comment that Cubelets can be an interesting model for understanding how the beauty and complexity of real life could, in fact, have evolved from simple, understandable components."

Right now the market is hobbyists and informal education, and Schweikhardt thinks science centers and children's museums would be a good fit. Soon they'll be creating the Cubelets in large quantities, and the price will go down, making the blocks affordable for anyone interested in robotics.

Since the blocks are modular, there is no end to what sort of blocks and behavior could be added in the future. "We're working on lots of different sensors, but my three favorites are the Hinge Block, which can be daisy-chained to create snake robots, the Prismatic Block, where one face extends to two times the block length, and the Bubble Blowing Block." We're voting for a teeny-tiny, adorable machine gun block ourselves.

Cubelets is a great idea, and watching them work in video form makes me want to put something together. We're hoping to get our hands on a loaner set soon to give you the lowdown on build quality and ease of use, but for now you can request information on future availability directly from the manufacturer.