Rocket-Powered Bionic Arm Successfully Tested

amigoro writes "A rocket-powered bionic arm has been successfully developed and tested by a team of mechanical engineers at Vanderbilt University as part of a $30 million military program to develop advanced prosthetic devices for next generation of super-soldiers."

Comments

Try "rocket *fuel* powered"...

[vanyel]

There's no rockets involved, it's actually steam powered, fueled by rocket fuel (hydrogen peroxide).

Re:Try "rocket *fuel* powered"...

[TubeSteak]

Picture:
http://www.vanderbilt.edu/exploration/resources/bi onicarm_CAD-arm_800.jpg
Caption:
A solid model of the arm shows how it works. The propellant cartridge contains the pressurized monopropellant. The liquid is routed through two flexible lines (not shown) across the elbow join and into two catalyst packs: one for the elbow and one for the foream. The catalyst increases the effective volume of the propellant by 1000 times. The propellant does not flow continuously but is controlled and routed by the servo valves just downstream. By rotating to different positions, a servo valve routes the gas to one side or the other of a gas cylinder, pusing the piston up or down. The entire operation is computer controlled, based on force and motion feedback from the joints.

Hydrogen peroxide + catalyst = hot gas (steam)
Sounds to me like they're talking about a liquid fuel rocket motor.

That pic + text was alongside the main article:
http://www.vanderbilt.edu/exploration/processor.ph p?action=get_section_text&id=1311&r=664693

About halfway down they get into the details of how it works & why they call it a rocket motor. Towards the bottom you can read about the engineering challenges they faced.

Re:Try "rocket *fuel* powered"...

[Tmack]

Hydrogen peroxide? Hmm. Novel concept. When you accidentally scrape the fur off your cat while petting it, you can simply open up an arm valve nozzle and spray the flesh wound sterile.

The high concentrate used as rocket fuel (up to 90% or better, read the early stages of http://armadilloaerospace.com/ when they were playing with this stuff) would ignite the cat on fire almost immediately on contact. Stuff that comes in the brown bottle is 1% or less usually (whitening toothpaste can be around 5%).

Tm

Re:Efficiency, not so much

[Eponymous Bastard]

Yeah, but a steam engine works by steam created by boiling normal water with an external power source and using the pressure. This works by burning H2O2 which ends up producing steam and then this high-pressure steam is used. It's not external combustion. It's closer to an internal combustion engine, actually.

I wouldn't call this a rocket, but it does seem to mix rocket engines (for high pressure gas generation) with steam engines (for harnessing high pressure gas). The closest thing I can think of is a car's air bag, quickly creating high pressure gas but not using that for propulsion. Or maybe a car's engine pushing against the pistons.

I guess the nomenclature is the hardest part about this article.

Re:I don't know what the rocket adds...

[Xiph]

then take a look at it at the original story It's actually a solid state hydrogen peroxide H2O2, it is the steam that drives powers the mechanics.
I guess it could be considered rocketry in that it's solid to gas transition. Also, it's what the astronauts use in spacewalk jetpacks

Amazing Video

[fractalVisionz]

Check out the video on vandy's website. I love the last few seconds where the robotic are is about to cap someone!

Re:Efficiency, not so much

[georgewilliamherbert]

The term you are looking for is "Gas Generator".

Rocket is something that generates gas (usually by combustion or decomposition) and expels it through a nozzle for thrust.

Gas generator is generic for a device which produces gas. A boiler is a special case (heat + water). There are gas generators in airbags (solid azide chemical reaction), other industrial uses too.

This just uses decomposing hydrogen peroxide to generate steam. Just another gas generator.

Nope, you're the first.

[Scrameustache]

Didn't it occur to anyone that the reason DARPA might be interested in this is the hundreds of vets with missing limbs who have a need for better prosthetics? CARL: I got Games & Theory.

CARMEN: Games & Theory? That's Military Intelligence... Oh, Carl!

JOHNNY: Whoa Way to go, boy-yo!

RECRUITING SERGEANT: Next time we meet, I'll probably have to salute you. What about you, son?

JOHNNY: Infantry, sir.

RECRUITING SERGEANT: Well, good for you. The Mobile Infantry made me the man I am today.

Video link

[ZDRuX]

Here's the link to the video which shows the arm in action and talks a little about how it is made.

Steam powered, not rocket powered.

[camperdave]

This is a steam powered artificial limb. It has nothing to do with rocket power (thrust produced by ejecting reaction mass) other than the fuel.

Re:Disabled vets, anyone?

[cortex]

I am a member of the Univ. of Utah team working on the neural control part of the DARPA revolutionizing prosthetics projects. I can tell you definitively that this project is solely aimed at helping injured veterans. They have made a point of having the scientists and engineers working on this project meet people who have lost limbs while serving their country. It was very moving and motivational to meet these soldiers in person. I am pretty sure that the technology will also be made available to civilian amputees. The people I have met from the Pentagon do care a great deal about the lives and welfare of the people serving in the military, as well as all people in general.