New Electrode Maps Emotions

The electronic tattoo developed at Tel Aviv University. (Tel Aviv University)
The electronic tattoo developed at Tel Aviv University. (Tel Aviv University)

Researchers at Tel Aviv University have developed a new, more patient-friendly method of electromyography — recording electrical signals through the skin.

A novel skin electrode, produced at TAU’s Center for Nanoscience & Nanotechnology, now takes this procedure out of the laboratory, doing away with the cold, sticky gel used to enhance conductivity. The new electrode is comfortable and accessible. It allows users to carry on as usual with their daily routines, while monitoring their muscle activity for many hours, for a range of medical and other purposes.

One major application of the new electrode, already under development, may be the mapping of emotions. “The ability to identify and map people’s emotions has many potential uses,” Prof. Yael Hanein was quoted as saying in the Ministry of Foreign Affairs Newsletter.

“Advertisers, pollsters, media professionals and others — all want to test people’s reactions to various products and situations. Today, with no accurate scientific tools available, they rely mostly on inevitably subjective questionnaires. To address this need, researchers worldwide are trying to develop methods for mapping emotions by analyzing facial expressions, mostly via facial photos and smart software. Our skin electrode provides a simple, convenient solution: monitoring expressions and emotions based on the electric signals received from facial muscles.”

Other potential applications include monitoring the muscle activity of patients with neurodegenerative diseases; physiological data measured in specific muscles may be used in the future to indicate the alertness of drivers on the road; patients in rehabilitation following stroke or brain injury may utilize it to improve muscle control; and amputees may employ it to move artificial limbs with remaining muscles.

The highly promising new skin electrode is based on a surprising fusion of nanotechnology with a very basic and commonplace product: the temporary tattoos that children love.

“We used readily available materials and conventional industrial printing techniques, in order to simplify and speed up the development process,” says Prof. Hanein. “Our ‘electric tattoo’ consists of three parts: a carbon electrode, an adhesive surface that sticks temporary tattoos to the skin and a nanotechnology-based conductive polymer coating, with special nano-topography, that enhances the electrode’s performance. The result is an efficient skin electrode that records a strong and steady signal for many hours, and does not irritate the skin. The user just fixes it onto the skin at the right spot and forgets about it, then carries on as usual while the little ‘tattoo’ measures and records muscle activity.”