20: Pounds of pressure per square inch required to fully close the robotic fingers. Brian Klutch

In the field of soft robotics, engineers use squishy materials to make robots durable, flexible, and safer to operate around humans. Now intrepid DIYers can also bring life to squishy machines: Last September, Harvard University published an open-access Soft Robotics Toolkit online. Some of the materials and skills Harvard recommends may be beyond the reach of a typical garage roboticist. But with a little ingenuity, you can substitute cheaper parts and simpler techniques. This project makes actuated “fingers” out of ribbed hose from a cheap foot pump, long thin balloons (the type you can twist and fold into animals), and other basic items. By attaching five fingers to a limb–in this case, a plastic gauntlet from a set of toy armor—you can form a robot hand. Once you’ve assembled your appendage, it’s time for phase two of the project: building a fluidic control board. The Arduino brain controls and coordinates air valves to make the hand flash the peace sign, hang loose, or even flip the bird. A


Time 8 hours

Cost $70 (hand), $400 (control board) Difficulty

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