
An MIT-developed inflatable robotic hand gives amputees real-time tactile control. The smart hand is soft and elastic, weighs about half a pound, and costs a fraction of comparable prosthetics.
Courtesy of the researchers
Prosthetic enables a wide range of daily activities, such as zipping a suitcase, shaking hands, and petting a cat.
For the more than 5 million people in the world who have undergone an upper-limb amputation, prosthetics have come a long way. Beyond traditional mannequin-like appendages, there is a growing number of commercial neuroprosthetics — highly articulated bionic limbs, engineered to sense a user’s residual muscle signals and robotically mimic their intended motions.
But this high-tech dexterity comes at a price. Neuroprosthetics can cost tens of thousands of dollars and are built around metal skeletons, with electrical motors that can be heavy and rigid.
Now engineers at MIT and Shanghai Jiao Tong University have designed a soft, lightweight, and potentially low-cost neuroprosthetic hand. Amputees who tested the artificial limb performed daily activities, such as zipping a suitcase, pouring a carton of juice, and petting a cat, just as well as — and in some cases better than —those with more rigid neuroprosthetics.
The researchers found the prosthetic, designed with a system for tactile feedback, restored some primitive sensation in a volunteer’s residual limb. The new design is also surprisingly durable, quickly recovering after being struck with a hammer or run over with a car.
The smart hand is soft and elastic, and weighs about half a pound. Its components total around $500 — a fraction of the weight and material cost associated with more rigid smart limbs.
“This is not a product yet, but the performance is already similar or superior to existing neuroprosthetics, which we’re excited about,” says Xuanhe Zhao, professor of mechanical engineering and of civil and environmental engineering at MIT. “There’s huge potential to make this soft prosthetic very low cost, for low-income families who have suffered from amputation.”
Zhao and his colleagues have published their work today in Nature Biomedical Engineering. Co-authors include MIT postdoc Shaoting Lin, along with Guoying Gu, Xiangyang Zhu, and collaborators at Shanghai Jiao Tong University in China.

Big Hero hand
The team’s pliable new design bears an uncanny resemblance to a certain inflatable robot in the animated film “Big Hero 6.” Like the squishy android, the team’s artificial hand is made from soft, stretchy material — in this case, the commercial elastomer EcoFlex. The prosthetic comprises five balloon-like fingers, each embedded with segments of fiber, similar to articulated bones in actual fingers. The bendy digits are connected to a 3-D-printed “palm,” shaped like a human hand.
Rather than controlling each finger using mounted electrical motors, as most neuroprosthetics do, the researchers used a simple pneumatic system to precisely inflate fingers and bend them in specific positions. This system, including a small pump and valves, can be worn at the waist, significantly reducing the prosthetic’s weight.
Lin developed a computer model to relate a finger’s desired position to the corresponding pressure a pump would have to apply to achieve that position. Using this model, the team developed a controller that directs the pneumatic system to inflate the fingers, in positions that mimic five common grasps, including pinching two and three fingers together, making a balled-up fist, and cupping the palm.
The pneumatic system receives signals from EMG sensors — electromyography sensors that measure electrical signals generated by motor neurons to control muscles. The sensors are fitted at the prosthetic’s opening, where it attaches to a user’s limb. In this arrangement, the sensors can pick up signals from a residual limb, such as when an amputee imagines making a fist.
The team then used an existing algorithm that “decodes” muscle signals and relates them to common grasp types. They used this algorithm to program the controller for their pneumatic system. When an amputee imagines, for instance, holding a wine glass, the sensors pick up the residual muscle signals, which the controller then translates into corresponding pressures. The pump then applies those pressures to inflate each finger and produce the amputee’s intended grasp.
Going a step further in their design, the researchers looked to enable tactile feedback — a feature that is not incorporated in most commercial neuroprosthetics. To do this, they stitched to each fingertip a pressure sensor, which when touched or squeezed produces an electrical signal proportional to the sensed pressure. Each sensor is wired to a specific location on an amputee’s residual limb, so the user can “feel” when the prosthetic’s thumb is pressed, for example, versus the forefinger.
Good grip
To test the inflatable hand, the researchers enlisted two volunteers, each with upper-limb amputations. Once outfitted with the neuroprosthetic, the volunteers learned to use it by repeatedly contracting the muscles in their arm while imagining making five common grasps.
After completing this 15-minute training, the volunteers were asked to perform a number of standardized tests to demonstrate manual strength and dexterity. These tasks included stacking checkers, turning pages, writing with a pen, lifting heavy balls, and picking up fragile objects like strawberries and bread. They repeated the same tests using a more rigid, commercially available bionic hand and found that the inflatable prosthetic was as good, or even better, at most tasks, compared to its rigid counterpart.
One volunteer was also able to intuitively use the soft prosthetic in daily activities, for instance to eat food like crackers, cake, and apples, and to handle objects and tools, such as laptops, bottles, hammers, and pliers. This volunteer could also safely manipulate the squishy prosthetic, for instance to shake someone’s hand, touch a flower, and pet a cat.
In a particularly exciting exercise, the researchers blindfolded the volunteer and found he could discern which prosthetic finger they poked and brushed. He was also able to “feel” bottles of different sizes that were placed in the prosthetic hand, and lifted them in response. The team sees these experiments as a promising sign that amputees can regain a form of sensation and real-time control with the inflatable hand.
The team has filed a patent on the design, through MIT, and is working to improve its sensing and range of motion.
“We now have four grasp types. There can be more,” Zhao says. “This design can be improved, with better decoding technology, higher-density myoelectric arrays, and a more compact pump that could be worn on the wrist. We also want to customize the design for mass production, so we can translate soft robotic technology to benefit society.”
Original Article: Inflatable robotic hand gives amputees real-time tactile control
More from: Massachusetts Institute of Technology | Shanghai Jiao Tong University
The Latest Updates from Bing News & Google News
Go deeper with Bing News on:
Robotic hand
- Robot waiter serves up Korean chicken and smiles in Aurora
If you have a meal at bb.q Chicken in Aurora you may be in for a surprise when you get your order because a robot will likely bring your order. "I like to call it Woodstock," said manager, Alex ...
- Researchers invent robotic 'hand' to pick blackberries
Researchers have developed a robotic "hand," resembling a claw, to pick blackberries. Their aim is to eventually automate blackberry harvest to help growers who face rising labor costs and a ...
- Someone built a robot to pick your guitar strings so you don’t have to
Now, Kvern has masterminded a robot that works in tandem with the player ... What makes it all work is his right hand, his picking hand. It’s like a machine.' A machine, I thought, at that moment. I ...
- Guitarist creates a string-picking robot
Guitar player Olav Kvern has built a robotic device that fits to an electric guitar and ... What makes it all work is his right hand, his picking hand. It’s like a machine,'" Kvern writes on ...
- ‘Finger-Gaiting’ Robot Can Feel What It’s Holding, Adjust Grip
Using a skill typically reserved for living creatures, this robot hand can sense objects and change its grip accordingly.
Go deeper with Google Headlines on:
Robotic hand
[google_news title=”” keyword=”robotic hand” num_posts=”5″ blurb_length=”0″ show_thumb=”left”]
Go deeper with Bing News on:
Neuroprosthetic hand
- Make up and razors: What items are not allowed in hand luggage?
With the summer months approaching, you might be starting to organise your suitcase for a holiday. When travelling abroad, you’ll need to be aware of the things you can and can’t take in your ...
- How One of New York’s Last Bagel Masters Rolls Thousands by Hand
From 2 a.m. until late in the afternoon, he’s in the kitchen, mixing and hand-rolling dough in all kinds of flavors. Bagels can now be made by machine, so there aren’t many masters of the form ...
- 7 Steps to Washing Your Hands Properly
Share on Pinterest According to the Centers for Disease Control and Prevention (CDC), proper hand hygiene is vital to lowering infectious disease transmission. In fact, research has shown that ...
- Harry and Meghan: Agency refuses to hand over photos
A photo agency that took pictures of the Duke and Duchess of Sussex during what the couple said was a dangerous car chase has refused to hand over the images to them. Backgrid told BBC News it had ...
- The "Red Right Hand" of "Ted Lasso": How the song with a murder narrative fits Roy Kent
The song in this case is "Red Right Hand" by Nick Cave and The Bad Seeds, and in its "Ted Lasso" premiere, the character who strides out to its unmistakable accompaniment is none other than Roy Kent.
Go deeper with Google Headlines on:
Neuroprosthetic hand
[google_news title=”” keyword=”neuroprosthetic hand” num_posts=”5″ blurb_length=”0″ show_thumb=”left”]