Moving toward more lifelike artificial limbs

Replacement limbs of the future could be created from body-friendly compounds that prevent injury, improve strong and flexible materials that generate the electricity needed to transmit signals, and join directly with neural implants to produce more natural movements.

Researchers at the University of Arizona presented a six-inch-tall robot driven by the eyes and brain of a hawk moth at the annual Society of Neuroscience meeting. Scientists say that the “robo-moth” hybrid could have interesting implications for neural implants, allowing better control over limbs immobilized by paralysis or replaced by prosthetics. By implanting an electrode in a neuron that stabilizes moth vision during flight, researchers found that the moth could steer the robot to the left or right direction for about a minute and a half. This was accomplished by using electrical signals amplified in the robot and translating those signals into action through a computer attached to the robot. However, Charles M. Higgins, a professor of electrical engineering and neurobiology at the university, warns that many challenges remain. Other researchers have experimented with more advanced brain implants in primates, with non-invasive devices and electrode bypasses that send brain signals to the muscles that can be used to control artificial limbs.

Building strong and flexible prosthetic limbs has always been a challenge. Pradeep Sharma, a professor of mechanical engineering at the University of Houston, says that the solution may be found in piezoelectrics. Piezoelectrics are materials that produce an electric charge in response to mechanical stress. This means that applying any tension to the material, such as pushing, stretching, or deforming causes an electrical charge. “Because of this effect, it has a natural application for prosthetic limbs,” Sharma said. “Our human body works in the same way: you send a signal to the hand and the hand will move.”

Some piezoelectric materials offer significant force, but are too fragile to provide a reasonable range of motion. Sharma is exploring at the nanoscale level how to imitate piezoelectric properties in materials that work better for bioengineering but wouldn’t normally generate electricity. He and his colleagues found they could disrupt the materials’ symmetry slightly to make them behave like other electricity-generating materials. “Essentially, we’ve opened up a new dimension of engineering by saying you could also tweak the size of particles to tailor a response,” Sharma said. For prosthetics, this technique could change the size and symmetrical arrangement of the particles in order to improve the strength of prosthetic limbs while generating the electrical signals needed to control motion.

I found this article interesting because it presents different technologies combining together to create better artificial limbs. It is interesting how machines will interact with cells and tissues in order to achieve certain purposes and improve human health.

http://www.msnbc.msn.com/id/24389431/