Soft grip: Pneumatic elastomers as robotic arms

January 21, 2011, Wiley

( -- It looks like a starfish made of soft plastic. When air is blown into it through a thin tube it comes to life and the starfish closes like a hand. It does this so gently that it can grasp a raw egg without breaking it. This starfish-like grabber is the prototype for a pneumatic soft robotic arm made of soft plastic that has been introduced in the journal Angewandte Chemie by George M. Whitesides and his team at Harvard University (Boston, USA).

Whether used in the production of machines or modern surgery, in the deactivation of explosive devices or unmanned spacecraft, robots have become indispensable in many areas. However, the manipulation of delicate objects, such as fruit or internal organs, remains a difficult task for conventional hard robotic arms. It could be easier with soft robot components.

Whitesides and his co-workers want to realize this idea with a new approach based on pneumatic networks (PneuNets): they embedded channels in elastic plastics known as elastomers. To actuate movement, the channels are simply inflated like balloons. This causes the channels to expand into those areas of the elastomer that are the most yielding. In homogeneous elastomers, these are the areas with the thinnest walls; if there are different materials they are the areas with walls made of the softer, more elastic of the materials.

To make room for all of the bulky inflated channels next to each other, the entire component curves so that the more severely stretched walls are on the outside. To produce prototypes capable of complex movement, the researchers combined a series of such components.

How the component deforms depends on both the design and the materials used. Whitesides and his co-workers joined parts made of two different stiff silicon elastomers to program the movement. They were thus able to make starfish-like grabbers. Inflating these devices causes them to curl around an object to grasp it like fingers on a hand. Their touch is so soft that they can even be entrusted with a raw egg or a living mouse. In contrast to hard robotic arms, no complex precisely tuned control with sensors is necessary.

Explore further: Diagnosis by Patterned Paper

More information: George M. Whitesides, Soft Robotics for Chemists, Angewandte Chemie International Edition,

Related Stories

Diagnosis by Patterned Paper

January 29, 2007

Testing biological fluids such as blood and urine is essential for both diagnostics and routine checks. In remote, non-industrialized regions or for emergency on-the-spot diagnosis, current methods of laboratory analysis ...

Cockroach inspires robotic hand to get a grip

January 10, 2011

No one thinks twice about picking up a cup of coffee, but this task has vexed robots for three decades. A new type of mechanical hand developed by researchers at Harvard and Yale promises to solve this problem.

Recommended for you

Researchers find tweeting in cities lower than expected

February 20, 2018

Studying data from Twitter, University of Illinois researchers found that less people tweet per capita from larger cities than in smaller ones, indicating an unexpected trend that has implications in understanding urban pace ...

Augmented reality takes 3-D printing to next level

February 20, 2018

Cornell researchers are taking 3-D printing and 3-D modeling to a new level by using augmented reality (AR) to allow designers to design in physical space while a robotic arm rapidly prints the work.

What do you get when you cross an airplane with a submarine?

February 15, 2018

Researchers from North Carolina State University have developed the first unmanned, fixed-wing aircraft that is capable of traveling both through the air and under the water – transitioning repeatedly between sky and sea. ...


Adjust slider to filter visible comments by rank

Display comments: newest first

5 / 5 (1) Jan 21, 2011
how about a video?
4 / 5 (1) Jan 21, 2011
how about a video?

Debbie Does Dallas?
not rated yet Jan 21, 2011
how about a video?

Debbie Does Dallas?

That's for wimps. Back door sluts 9. (Sorry, it's a southpark reference)
1 / 5 (1) Jan 21, 2011
Yet another robot hand contraption that doesn't break an egg. I'm. Not. Impressed. There have been a dozen articles with (insert robotic hand device) that say the same thing in the last year.
1 / 5 (1) Jan 21, 2011
Agreed, not exactly a First in tech. Just last fall there was this German elephant's trunk like robotic arm, and it had a hand that worked precisely like this one. (It did look a little different, but the working principle was exactly the same.)
not rated yet Jan 22, 2011
Actually, this is the best approach.

I have a similar design prototype for a muscle. and making a human form robot is simply a matter of duplicating the muscles and bones of a human body. admittedly there's several hundred muscles of various sizes that need to be duplicated for a full human form. fabrication of these is simpler than gears and electromoters by far and can be done with the equivalent of a sewing machine. but I'm still looking for reasonable priced off the shelf electric control valves and I have no budget at all or connections so it will probably never be developed my me. Oh well. someone else will build it soon enough it looks like. They can't be very far away now based on this. I've been wondering what took them so long for a few years now.
5 / 5 (1) Jan 22, 2011
It took a team of Harvard grads to do this?

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.