Welcome to squiz kids science shorts, the show where we take your big, curly questions and unpack the science stories everyone's talking about, break them down into snack size.
Science powered answers we sort the fact from the fluff.
Keep it fun, keep it fast and, whether it's happening in your body, your backyard or the big wide universe, we're here to explain the science behind the headlines.
What if your arm stopped working and doctors built you a new one that listens to your muscles?
This question comes in from Amelia, who wants to be a doctor, and she asks can humans be part robot?
The short answer, yes, but not in the science fiction glowing red eyes kind of way.
Let's start with why this technology exists in the first place.
Some people lose a limb because of a severe injury, an infection, cancer or blood circulation problems.
And some people are born with limb differences, where a part of a limb doesn't form fully or doesn't function typically.
Prosthetic limbs aren't upgrades.
They're tools designed to restore movement, independence and confidence.
Now, here's where it gets fascinating.
Your body already runs on electricity mm-hmm.
Every time you move your hand, your brain sends a tiny electrical signal down your nerves to your muscles and those signals tell the muscles to contract.
Modern robotic arms can detect those signals.
Sensors placed on the skin pick up muscle activity and when you think about bending your elbow, the muscles activate.
The prosthetic reads the electrical signals and moves.
But there's a little problem.
In traditional amputations muscles are cut and no longer work in pairs.
Now, normally muscles operate as what's called agonist and antagonist partners, kind of like a push-pull pair.
One tightens while the other relaxes, like your biceps and your triceps working together to bend or straighten your arm.
When that partnership is lost, neural signals can drop to around about 3 of their original strength only 3.
And that makes controlling a robotic limb really difficult.
It's like trying to steer something with a signal that's barely there.
So research has developed a surgical technique where, instead of simply closing off the limb, they reconnect those muscle pairs so that they can still pull against each other.
And that restores a stronger, clearer signal and gives the brain much better information.
But the movement is only half of the story, because think of how many things you do without looking at your hands or your feet, like maybe typing or picking up a paper cup or walking around without staring at your feet.
You rely constantly on two hidden senses number one, touch.
Number two, proprioception.
That's your internal sense of where your body is in space.
And if you've ever tried doing up buttons while wearing thick gloves, then you know how frustrating it is when your sense of touch is muffled.
Without this feedback, you have to constantly watch your hands and you risk crushing or dropping objects.
So scientists aren't just building robotic arms that move, they're building arms that feel.
New prosthetics include pressure sensors in the fingertips.
Those signals can stimulate nerves in the remaining limb, sending information back the other way to the brain.
And now the system becomes a loop again.
Brain sends command, muscle activates, prosthetic limb moves.
Senses send feedback, brain adjusts.
It kind of becomes a conversation.
And when that loop is restored, people can grip fragile objects without looking.
They can sense how hard they're holding something and they can move more naturally.
So, Amelia, can humans be part robot?
Well, in some ways we already are.
Pacemakers to regulate heartbeat.
Cochlear implants to restore hearing.
Insulin pumps to monitor blood sugar.
These technologies don't replace humanity.
They work really well alongside it.
And here's a mind bending bit.
Your nervous system already works like a biological machine.
It sends electrical signals, it processes feedback, and it adjusts the output.
So robotic limbs don't turn humans into machines.
They tap into the biological machines that we already are.
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On next week's Squiz Kids Science Show.
