It may soon become commonplace to see people with robotic exoskeletons or bionic eyes.
Scientific research into bionic human parts has advanced impressively in recent years, driven by improvements in computer science, shrinking electronic components, and a growing understanding of the nervous system.
Some of these devices are simply meant to help people regain normal functions — like eye implants that provide sight for the blind.
But other researchers, particularly those interested in military technology, are looking for ways to make humans bigger, better, and stronger.
Here's a look at five of the most intriguing areas of research into bionic humans:
1) Exoskeletons to help people walk
External skeletons are something that crustaceans and insects have naturally. And now researchers are working on exoskeletons for humans, too. Some devices are meant to enhance the strength of people who have been weakened from paralysis or old age. But the military is also looking at exoskeletons to make people stronger.
In June of 2014, the FDA approved the first exoskeleton for medical use: ReWalk. The system consists of motorized leg braces that someone tells to walk, stand up, or sit down using a remote control. The person also wears a backpack housing ReWalk's power supply and computer. The device is specifically approved for people with lower-body paralysis.
The military has also been a big player in this field. Ekso Bionics previously developed the hydraulic powered HULC (Human Universal Load Carrier), which Lockheed Martin is now developing for military and industrial uses. Lockheed's website describes the HULC as something that could help military personnel carry up to 200 pounds of heavy combat gear for extended periods of time without fatigue. And Raytheon also has a suit: the XOS.
Several other programs having also been developing strength suits for military use, including US Special Operations Command's TALOS (Tactical Assault Light Operator Suit), which seeks "an advanced infantry uniform that promises to provide superhuman strength with greater ballistic protection," according to a US Army statement. And Darpa's Warrior Web program has the goal of a soft, pliable supersuit.
2) Bionic eyes that give sight to the blind
There are many researchers working on bionic eyes, but Second Sight's Argus II implant became the first FDA-approved bionic eye in 2013. And it actually does give sight to the blind — it's approved for people with retinitis pigmentosa, a disease that affects more than 2 million people around the world.
The Argus II involves a 60-electrode array that gets implanted in the eye in order to restore its function. A camera mounted on a pair of glasses records visual information about the world. This info then gets parsed by a small video-processing unit. Then this information gets wirelessly transferred to the electrode-array implant, which activates neurons in the back of the eye and sends messages to the brain.
So far, the resolution is limited, and it definitely doesn't bring people anywhere near 20/20 vision. But it provides enough grayscale resolution to let people see the outline of a doorway, the movement of a person or large object, or the lines on a crosswalk. Some have even been able to identify letters of the alphabet that are a few centimeters tall.
Second Sight is currently working to bring the technology to even more people. They announced in September that they'll be starting trials for blind patients with age-related macular degeneration, which affects 20 to 25 million people worldwide.
And if this seems totally nuts to you, keep in mind that bionic ears — cochlear implants — are already worn by some 300,000 people.
3) Robot limbs that can be controlled by the mind
One of the most impressive pieces of bionics research has been the BrainGate project, which uses brain implants in people with paralysis to allow them to physically interact with the world.
The implant has 96 electrodes that read signals from the brain. And with intensive and long training, some patients have been able to use the system to do some impressive things.
In a study published in Nature in 2006, researchers showed that a patient could use the system to move a computer cursor, open simulated email, and operate a television. And in 2012, they followed up with another paper and showed that two people used the system to instruct a robot hand to pick things up. One patient who had the implant for five years was even able to use the robotic hand to drink coffee. The project still continues today, and researchers are currently recruiting for even more trials.
4) Prosthetic limbs that feel like part of your body
Prosthetic limbs have existed for some time — but now they're getting smarter.
For example, Touch Bionics' i-Limb Ultra, a prosthetic hand with motorized joints, can smartly shape itself to an object someone is trying to grasp or read muscle signals from the skin of someone's upper arm to take on a pre-programmed configuration.
More promising still, researchers are now working on experimental bionic limbs that can communicate more intuitively with people's bodies. This can involve sensors on the skin or even sensors implanted into the body, such as the IMES muscle sensors being used with experimental prosthetics on real people. "I still close what I think is my hand," James Sides told Popular Science. "I open my hand, and rotate it up and down; I close my fingers and the hand closes. It’s exactly as if I still had a hand."
Another possibility is to interface with implants that attach directly to people's nerves and brains.
The next step beyond that is getting feedback from the limb back to the person so that people can feel these prosthetics. This research is still in early stages, but people have seen that having a feel for what's actually going on can improve dexterity.
5) Deep-brain stimulation to treat brain ailments
The brain sends signals using both chemicals and electricity. And for decades the main way to intervene and fix brain problems was through the chemical side — through drugs.
But recently that has begun to change. Some people now receive implants in their brains that give off electrical currents to simulate their brain cells. Think of it as a pacemaker for the brain.
This technique is called deep-brain stimulation. And it's already FDA-approved for treating Parkinson's disease and a movement disorder called dystonia. Medtronic's deep-brain stimulation system, for example, has been implanted in some 110,000 people. The technique has also been tested in people for psychiatric illnesses, including obsessive-compulsive disorder and severe depression.