BusinessTN

A prosthetic digit the size of a human finger--only stronger. A robotic arm that can disable a bomb. A lightweight device that can strengthen a weak joint.

These are just a few of the applications that scientists in Oak Ridge National Laboratory's Robotics and Energetic Systems Group are developing with a new technology called mesofluidics. Though the word itself is a bit of a mouthful, the technology, says ORNL research scientist Lonnie Love, is "nothing more than miniaturized hydraulics." Love explains that hydraulic motors power farm and construction equipment, such as backhoes.

"You get a lot of power and strength in a pretty light package, so we shrunk that technology down by a number of orders of magnitude, and we're using it right now in prosthetics," Love says.

ORNL initially developed a mesofluidic prosthetic finger and elbow for the Defense Advanced Research Project Agency's (DARPA) Revolutionizing Prosthetics Program, which was launched in 2006 to create a fully functional upper limb to improve quality of life for the growing number of war amputees. The mesofluidic products are quite an improvement from today's prostheses, which are typically powered by electric motors.

"The amount of force you can generate [with an electric motor] is an order of magnitude lower than what you can do with hydraulics, so the prostheses are quite a bit heavier than mesofluidics, and they also get really hot, so temperature is a problem," Love says.

With mesofluidic technology, fluid is pumped through the structure at a pressure of about 2,000 pounds per square inch and provides the primary means for driving the joints on the fingers and elbows. The finger that the ORNL scientists demonstrated to DARPA is capable of producing 20 pounds of pinch force, which is about five to 10 pounds more than a typical human finger. The mesofluidic elbow can curl 60 pounds--a feat most human elbows could not accomplish.

After the first phase of the program, DARPA switched its focus to the neural control aspect of prosthetics.

"DARPA decided that the hydraulics are workable, but they need to spend funding on a bigger problem--the controls," Love says. "We can make an arm that has the same dexterity as the human arm, but how do you control it?"

In the meantime, ORNL is leveraging its knowledge about mesofluidics for a variety of applications. For example, Love says the group is developing a mesofluidic arm for the Navy to be used for explosive ordinance disposal.

"Instead of having a technician go out and try to disable a weapon, we will have a pair of arms much like human arms that can go on a mobile robot and remotely take apart a weapon," Love says.

He says members of the military have also expressed interest in using the technology for underwater robotics and micro unmanned aerial vehicles. And there's also work to be done in the way of lower limb prostheses. ORNL is collaborating with Oklahoma City-based OrthoCare Innovations, a medical device research and product development company that focuses on commercializing technologies in the rehabilitation and elder care markets, to develop mesofluidic-based prosthetic devices for ankles, knees and hips. David Boone, the chief technology officer for OrthoCare, says mesofluidics allow the creation of prostheses that are as powerful and the same size and shape as the human limbs that they are replacing.

"If you look at someone's leg, there is a fairly limited amount of space that we have in our actual limb to provide the power and motion that has been lost," Boone says. "The natural body is incredibly efficient, and mesofluidics allow us to provide extremely efficient power in a very small package, getting us closer to the type of power that is lost with the body."

In addition to a mesofluidic ankle and knee, ORNL and OrthoCare are developing a mesofluidic-based alignment device for actively aligning a prosthetic leg with the limb.

"Alignment is difficult to do well because there haven't been instruments for optimizing that dynamically," Boone says. "What we've done with Lonnie is develop a mesofluidic adjuster that moves the leg automatically underneath you in order to keep your balance. That's a very significant thing."

Finally, Love says he has an internal ORNL project focused on "wearable robotics"--lightweight devices worn like braces to provide extra strength to a weak joint.

"Not like superman, but primarily to help restore what is lost through injury or aging," Love says. "For example, a glove that can help with gripping, or active leg braces that can assist in walking."

Though the Robotics and Energetic Systems Group at ORNL may not be creating superheroes, it's certainly on its way to revolutionizing the prostheses industry.