Engineers Develop Robotic Microhand

Early this winter, two engineers announced they had developed a tiny pneumatic hand with the ability to grasp objects smaller than a millimeter across. As it runs on gas pressure rather than electricity, it can be used in both wet and dry environments, making it safe for biological environments — good news for surgeons who hope to use the tiny tool in minimally invasive surgical techniques.

As the medical world becomes ever more portable, the need for smaller, lighter devices is becoming more important: smaller, portable monitoring equipment that patients can carry and operate themselves and wireless technology that is being used in implantable medical devices to send back data from inside a patient's body.

From portable defibrillators to cutting-edge portable pulse CO-oximeters, medical devices are downsizing, becoming tinier, more handheld.

Then there actually a tiny hand, itself for holding.

A microscopic robot hand, made of silicon and plastic balloons, could help perform minimally invasive surgeries. A new feat of microscale mechanical systems, or MEMS, this "microhand" measures at a mere 1 millimeter when closed to a fist.

The seriously tiny gripper, created in Professor Chang-Jin Kim's Micromanufacturing lab at the University of California, in Los Angeles (UCLA), uses inflatable polymer balloons as actuators between a series of silicon wafers. Researchers are hoping this tiny device will come in handy for remote microsurgery applications in the next few years. Research also includes microscopic liquid-metal motors and other small actuators that might eventually power the incredibly small robots of our future.

According to MIT's Technology Review:

It consists of four "fingers," each of which is made from six silicon wafers, with polymer balloons doing the work of "muscles" at the wafers' joints. Each balloon is connected with narrow channels through which air is pumped in or out. When a balloon is inflated, the distance between two joints decreases, and the finger flexes inward. Upon deflation, the fingers relax. And with selective inflation and deflation, researchers are able to manipulate the fingers into clasping or releasing an object.

"The field of microsurgery and minimally invasive surgery is currently dominated by grippers and tools that are Microscopic Robot Lends Helping Hand.jpgmounted at the end of long, rigid aluminum rods," Albert Pisano, a mechanical engineer at the University of California, Berkeley, and a leader in such research, told Technology Review. "Certainly these are adequate for many purposes, but now that functional microhands have been developed, one can visualize a new set of minimally invasive surgical tools that allow the surgeon additional dexterity in complicated procedures."

Pisano said that the technology could enable new kinds of minimally invasive surgical techniques, and that it stands out from other such efforts. Prof. Kim's work is particularly noteworthy, according to Pisano, because the his hand has two pairs of opposing finger/thumb sets, and his design is able to have such an extreme range of motion.

Running on gas pressure rather than electricity, it can be used in both wet and dry environments, making it safe for biological environments. That is good news for surgeons who hope to use the tiny tool in future microsurgeries.

Further, according to LiveScience, the microscopic robot hand could also help diffuse bombs.

"You could imagine this being used for microsurgery — at the end of a catheter, for instance. We found we could grab a nerve bundle with it," Kim told LiveScience. "We are also working with a company who said this could help disarm explosives. Right now the robotic manipulators used there are pretty crude, and a gentle and dexterous hand would be helpful."

The microhand, which is gentle but strong enough to pluck a single delicate fish egg from a sticky egg mass, is probably years from practical use. (video)

The robot hand was designed by microelectromechanical systems scientist Yen-Wen Lu at Rutgers University in New Jersey, and mechanical engineer Chang-Jin Kim at UCLA, according to a Live Science news report earlier this winter. UCLA's Micro Electro-Mechanical Systems (MEMS) program is one of the fastest growing research programs in the school, with active faculty and student participation from the Departments of Mechanical and Aerospace Engineering, Electrical Engineering, and Materials Science and Engineering. Lu and Kim reported their findings online in October 2006, via the journal Applied Physics Letters.

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