Health x technology: Making prosthetics feel natural for users – for a lifetime

The human hand is an extraordinarily versatile piece of nature's engineering. It can carry out a dextrous task like pulling a coin from a pocket, a hard task like changing a car tyre, or the gentle task of changing a baby's diaper. When we use a hand, we don’t consciously instruct it, we simply intend the action and the hand does it.   

That's precisely the kind of relationship Professor Ivan Vujaklija at Aalto University wants to create between a person and a prosthesis. ‘I want the patient of the future not to have to think about working with their prosthesis, but to just do it,’ he says.

Communication not capability the bottleneck

What’s holding Vujaklija back is not the prosthetic hand itself. Today’s robotic hands are already remarkably capable. ‘We have fantastic state-of-the-art robotic systems, let’s be honest,’ he says. ‘But they’re not good prosthetics.’

The main challenge is that the wearer still can’t easily access all that capability. The challenge for Vujaklija and his team is not so much building a better robotic hand but building a better interface between the hand and the person controlling it.

Finding a better solution matters as people may now live much longer with their prosthetics than before. The number of amputees is growing, but the demographics are also changing.  

People are living longer, and conditions such as diabetes are important causes of amputation, particularly later in life. At the other end of the age spectrum, conflicts like the war in Ukraine are leaving young people facing decades of life with prostheses. 

‘We’re now supporting someone’s ability not just for 10 years,’ Vujaklija says, ‘but potentially for 30, 40, or 50 years.’

How does a hand know what a person wants it to do?

A prosthetic hand isn't successful just because it can mechanically grasp something. Vujaklija wants its control to become so intuitive that the wearer can rely on it as if it was part of their own body. ‘It should help restore autonomy and self-confidence in the wearer rather than being a tool that merely gets them by,’ he explains.

With a below-elbow amputation, the hand may be gone, but the remaining muscles in the forearm can still contract when the person intends to move it. This is the basis of prosthetic control technology dating back to the 1950s.

Electrodes placed on the skin detect tiny electrical signals from those muscles and use them to control the prosthesis, with traditionally one signal opening the hand and another closing it.

‘Two signals are fine if all you want to do is open and close the hand,’ Vujaklija says. ‘But today’s prosthetic hands can do so much more, and accessing all those additional functions quickly is cumbersome.’

‘That gives us a much richer picture of what's happening inside the muscles. And the goal isn't just more electrodes equal more commands. That's too simple,’ he says. 

Now, with much more detailed information to work with, he and his team can start picking apart the jumble of muscle activity to reveal when individual motor neurons in the spinal cord are firing to control the muscles.

Text: Laurel Colless.

The prosthesis developed by Professor Ivan Vujaklija’s research group is on display at Aalto University’s Designs for a Cooler Planet exhibition in the Marsio building on the Otaniemi campus until 30 October 2026.