Soft Robotics, Silicone Rubber, And Amazing Castings

March 24, 2014 by Brian Benchoff 13 Comments

Most of the robotics projects we see around here are heavy, metallic machines that move with exacting precision with steppers, servos, motors, and electronics. [Matthew] is another breed of roboticist, and created a quadruped robot with no hard moving parts.

[Matthew] calls his creation the Glaucus, after the blue sea slug Glaucus atlanticus. Inside this silicone rubber blob are a series of voids, allowing compressed air to expand the legs, gently inching Glaucus across a table under manual or automatic control.

Even though no one seems to do it, making a few molds for casting on a 3D printer is actually pretty easy. [Matthew] is taking this technique to an extreme, though: First, a mold for the interior pressure bladders are printed, then a positive of this print made in silicone rubber. These silicone molds – four of them, for the left, right, top and bottom – are then filled with wax, and the wax parts reassembled inside the final ‘body’ mold. It’s an amazing amount of work to make just one of these soft robots, but once the molds and masters are made, [Matthew] can pop out a soft robot every few hours or so.

There’s a lot more info on Glaucus over on the official site for the build, and a somewhat simpler ‘compressed air and silicone rubber’ tentacle [Matthew] built showing off the mechanics. Video below.

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Simplifying Fabrication Of Soft Robots

December 4, 2012 by Mike Szczys 27 Comments

Soft robots are a peculiar wing of technology. They don’t use frames and motors for locomotion, but as the name implies they are made of soft materials. They move by pumping fluid — it could be air or liquid — in and out of bladders that push or pull against the body itself. [Matthew] points out that fabricating soft robots has traditionally been a time-consuming and difficult task. He’s trying to make it easier by 3D printing molds into which soft robots can be cast. This way the parts can be designed in CAD, converted to a mold design, and pushed to a 3D printer.

The object with which he’s been testing the technique functions like an octopus tentacle. The image at the bottom left illustrates the internal structure, with rings separated to allow the appendage to flex, and tubes running parallel to the appendage to provide the force needed to bend it. Above that image you can see one of the molds that was used, and the final product is on the right. The video after the break shows a demonstration of this bending left and right as air is pumped in using the bulb of a blood pressure cuff (or Sphygmomanometer for those paying attention).

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Soft Robots Given Veins The Let Them Change Their Stripes

August 28, 2012 by Mike Szczys 21 Comments

If it were alive this robot would be classified as an invertebrate. It lacks a backbone and interestingly enough, all other bones are missing as well. The Harvard researchers that developed it call it a soft robot. It’s made out of silicone and uses pathways built into the substance to move. By adding pressurized air to these pathways the appendages flex relative to each other. In fact, after the break you can see a video of a starfish-shaped soft robot picking up an egg.

Now they’ve gone one step further. By adding another layer to the top, or even embedding it in the body, the robot gains the ability to change color. Above you can see a soft robot that started without any color (other than the translucent white of the silicone) and is now being changed to red. As the dye is injected it is propagating from the right side to the left. The team believes this could be useful in a swarm robotics situation. If you have a slew of these things searching for something in the dark they could pump glowing dye through their skin when they’ve found it. The demo can be seen after the jump.

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