New technology sends information through human touch

Engineers at Purdue University in Indiana, USA, have developed a new technology that they say makes it possible to transmit information through human touch.

The prototype is said to be the first technology that can send information through the direct touch of a fingertip, allowing the user’s body to act as a link between a payment card or smartphone and a reader or scanner.

While it can’t yet transfer money, researchers said that while wearing the prototype as a watch, a user’s body can be used to send information such as a photo or password when touching a sensor on a laptop. 

The study is published in the journal Transactions on Computer-Human Interaction and was led by Purdue alumnus Shovan Maity as a PhD student.

It describes how the technology works by establishing an ‘internet’ within the body that smartphones, smartwatches, pacemakers, insulin pumps and other wearable or implantable devices could send information. 

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Typically, these devices communicate via Bluetooth signals that radiate from the body. Shreyas Sen, associate professor of Electrical and Computer Engineering at Purdue, said that a hacker could intercept these signals from 30 feet away, explaining how this new technology would instead keep signals confined within the body by coupling them in a ‘Electro-Quasistatic range’ lower on the electromagnetic spectrum than Bluetooth communication. 

According to the team, information wouldn’t transfer through this technology without a direct touch, even if a finger hovered a centimetre above the surface, preventing hackers from intercepting the signals to steal private information. 

This was tested by having a person interact with two adjacent surfaces in the lab, each equipped with an electrode to touch, a receiver to get data from the finger and a light to indicate that data had transferred. Researchers confirmed that if a finger touched an electrode directly, only the light of that surface turned on while the that of the other surfaces remained off, indicating that no data had leaked out.

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A researcher transfers information from a chip in a watch by touching a sensor connected to a laptop. Credit: Purdue University/Photo by John Underwood

Credit card machines and apps such as Apple Pay use a more secure alternative to Bluetooth signals – near-field communication – to receive payments. Sen explained that their technology would add convenience of making a secure payment in a single gesture without bringing the device out of a pocket.

Researchers believe the technology could also replace key fobs or cards that currently use Bluetooth to grant access to a building: instead, a person could just touch a door handle to enter.

Implementing this technology in real-life would require surfaces everywhere to have the right hardware for finger recognition, and software on the device would have to be configured to send signals through the body to the fingertip – as well as having a way to turn off so that information wouldn’t be transferred to every surface equipped to receive it. 

“Anytime you are enabling a new hardware channel, it gives you more possibilities. Think of big touch screens that we have today – the only information that the computer receives is the location of your touch. But the ability to transfer information through your touch would change the applications of that big touch screen,” Sen said.

The team will present their findings at the Association for Computing Machinery’s Computer Human Interaction (ACM CHI) conference in May, 2021.