Tag Archives: biomimetic

Gone Fishin’

You have to see this.  It’s probably one of the coolest and simultaneously creepy pieces of technology I have run across lately.  It’s an artificial fish.

“But Mike, why do we need an artificial fish, when there are so many real ones around?” you might ask.

Well, there is a reason, aside from the sheer coolness factor.

It turns out that good ol’ Mother Nature has had a long time to work on stuff, and at this point has pretty much got it all figured out.  For example, how birds fly and fish swim using the minimal amount of energy.  See, in nature, if you can swim faster or father than other fish on the same amount of energy, or conversely, if you can swim as fast or as far as other fish on less energy, it means you have an advantage in the great circle of life, and you might get a chance to stick around longer.

For all our intelligence, we often have trouble coming up with stuff that is better than, or even close to, working as well as natural systems.  But over the past couple of decades, many researchers and engineers have realized that sometimes we need to just take advantage of all that work that Mother Nature has done for us and see if we can duplicate it.  You know, like copying the answers off the test of the person in front of you (not that I would know anything about that).

Anyway, take a look at this site, where some smart folks have created an artificial carp.  Well, it looks like one to me, anyway.  But the cool part is that it isn’t just a bunch of motors and gears attached to a frame and a skin, like a Walt Disney animatronic fish…this one actually works like a fish.

It uses a combination of composites and electroactive materials, along with very clever mechanical design and probably loads of math to make a fish that wiggles like a fish.  Just look at it.  It’s so cool and creepy!

The secret is that by passing electric current through certain types of materials, you can cause them to expand or contract just a little, sort of the way a real muscle works.  Some of these electroactive materials are made of polymers, which as you know are relatively soft.  Electroactive polymer “muscles” can move fairly large amounts when activated, but they are so soft that they can’t really exert much force.  On the other hand, there are much harder materials, like the little crystal inside your quartz-controlled watch, that can actually exert a lot of force, but they can’t change shape very much.  So, it would seem that both of these types of actuated materials have limitations.

True, but when you give them just the right shape and attach them to other structures just so, such as the artificial fish body, they can produce large, amplified movements that can be used to do significant work for you.

Now, back to the question of “Who cares?”  Well, the same design that creates the wiggly artificial fish body can also be use to slightly change the shape of a wing on an airplane, for example.  Airplane wings need to alter their shapes for different flying conditions, and being able to command the wing to take a slightly more efficient shape for cruising while morphing to a higher lift configuration for landing would save significant fuel (or extend range).  The artificial fish could be released in small schools or swarms to swim about and collect data on temperature or chemical content of a stream for environmental monitoring purposes, or as an early warning system for protecting ports from attack in a homeland security scenario.

The technology behind the creepy wiggly artificial fish is being developed by Dr. Wayne Neu of Virginia Tech’s Aerospace and Ocean Engineering group, along with private research company AVID.  Interestingly, AVID is also working on related technology that can be used to create actual flapping wing structures.  So, maybe soon we will have not just creepy artificial fish, but creepy artificial birds and insects.

NEAT!

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Filed under biomimetic, Energy, Materials, propulsion

It’s a Wire! It’s a Tube! It’s . . . Super-Foam!

Ever wonder where Governor Schwarzenegger got his Terminator skin?

Well, maybe not.  But if you recall, the Terminator robot in the film had a metallic skeleton with biological tissue over it, so that it looked just like a human being…if human beings were all bodybuilders from Austria, that is.  Anyway, tissue engineering is not just something they dreamed up in Hollywood.  It’s for real.  The idea is to duplicate bone and cartilage, for example, to make replacements for real tissue in our bodies when it wears out due to, oh, say, football injuries or skydiving, or maybe just being over 40.

So that’s what Virginia Tech Ph.D. candidate Michael Sano was working on one day when he noticed that sometimes the cellulose fibrils he was making were thinly coated with metal, resulting in tiny ‘nanowires’.  He quickly realized that by altering the solutions in his experiments, he could produce any type of nanowire he wanted to make.  He also learned that under the right conditions he could degrade the cellulose, leaving a ‘nanotube’.  By tweaking yet another parameter he could create a material that is best described as ‘metallic foam’.

From Sano’s engineering perspective, he could see he had solved a long-standing challenge for the field of nanotube construction: how to fuse sub-nano-sized segments together to extend them into something that still had a continuous hollow core and was long enough to be a functional nanotube.

Mike could also see that this was potentially a way to produce nanocircuitry in situ, allowing connections to be formed between points in ‘nanospaces’, if you will.

And the metallic foam?  Well, it is light-weight , strong, and can be produced from just about any metal ion you want.

Of course, none of this has anything to do with the Governator of California, as far as I know.

To read more about the project Mike Sano was working on when he made his discovery, you can go here.

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Filed under biotechnology, Materials