What would you do if you had a THIRD thumb? A robotic prosthesis allows people to open bottles, pick up objects and even peel a banana with one hand

Human hands have had 10 digits for millions of years.

But they look like scientists at the The University of Cambridge believes this is not enough.

The experts have created the ‘Third Thumb’: a steerable prosthesis that attaches to the edge of the right hand.

It allows wearers to pick up objects, open liquor bottles, search playing cards, peel a banana and even thread a needle – all with just one hand.

In their study, human volunteers quickly became accustomed to the extra digit – which “could push our motor abilities beyond current biological limitations.”

The study was led by researchers from the University of Cambridge’s MRC Cognition and Brain Science Unit and published in Science Robotics.

While they don’t see a future where humans naturally “develop extra thumbs” through evolution, their robot version could make people’s lives easier.

It can be particularly valuable for amputees who, for example, have lost an arm and have difficulty performing everyday tasks with only one hand.

“Our daily lives are already consumed by wearable technologies and we are now seeing more and more dedicated augmentation technologies being developed,” study author Lucy Dowdall told MailOnline.

‘The Third Thumb can be used to extend the function of the hand – so for any task that requires carrying multiple objects at the same time, or to stabilize one object while performing a task with another.’

Designer Dani Clode, a research technician at UCL’s Plasticity Lab, began developing Third Thumb as part of a graduate project at the Royal College of Art.

The third thumb is worn on the opposite side of the palm from a person’s real thumb and is controlled by a pressure sensor placed under each big toe.

Both toe sensors, which are wirelessly connected to the thumb, control different movements by immediately responding to subtle changes in toe pressure.

Pressure from the right toe pulls the prosthetic finger over the hand, while pressure applied with the left toe pulls it toward the fingers and releasing the pressure returns it to its original position.

In their study, the team tested 596 participants, ranging in age from three to 96 years old, who were given one minute to familiarize themselves with the device.

The thumb came in different sizes to fit the hands of children and adults.

The participants performed two tasks: first, picking up pegs and placing them in a basket, and second, manipulating and moving five or six different foam objects of varying sizes.

Overall, the thumb was worn and controlled successfully by 99.3 percent of the sample, the researchers found.

And 98 percent of participants were able to successfully manipulate objects using the Third Thumb during the first minute of use.

Older and younger adults had similar levels of skill in using the device, although further research within the age range of older adults revealed a decline in performance with advancing age.

“This effect could be due to the general decline in sensorimotor and cognitive skills associated with aging,” the team says.

‘Additionally, these effects may also reflect a generational relationship with technology.’

The thumb is “not commercially available” and it is unclear when and how the academics might make their device available to the public, or how much it would cost.

But they hope it can “pave the way to setting a benchmark” for other “inclusive” human-centric devices.

“Future augmentation technologies could have a major impact on society and be useful to many people,” they write.