Ultra-light tattoo electrodes offer breakthrough in brain monitoring

Ultra-thin and light-weight tattoo electrodes promise a revolution in the way scientists monitor and understand brain wave activity.

Back in 2015, Francesco Greco, head of the Laboratory of Applied Materials for Printed and Soft electronics at Austria’s Institute of Solid State Physics at Graz University of Technology, developed the concept of tattoo electrodes which offered a cheaper and easier way to monitor brainwaves.

Longevity.Technology: New technology is finding ways to collect larger quantities of biomarker data in a more consistent and comprehensive way. These dry tattoos represent a major step forward allowing extensive monitoring of the brain.

These new ultra-thin form of electrodes which resemble a tattoo offer an affordable way to study brainwaves for a prolonged period of time [1]. With a thickness of between 700 and 800 nanometres (0.0008mm), these opened up exciting new possibilities in electrocardiography (ECG) or electromyography (EMG). Building on this achievement they have now found a way to develop modified tattoo electrodes which can be used in electroencephalography (EEG) – in other words, to measure brain activity.

Ultra-thin and light weight tattoo electrodes promise a revolution in the way scientists monitor and understand brain wave activity.
Ultra-thin tattoo electrodes developed by the Graz University of Technology

Conventional approaches to Electroencephalography (EEG), which are often used to study brainwaves, are impractical when used for a prolonged period of time. Hard electrodes need gel to be applied and require the patient to wear a tight and uncomfortable cap.

With this new innovation, the researchers have found a way to use ultra-thin electrodes which can be worn for prolonged periods of time.

They are manufactured using inkjet printers and resemble a small tattoo at the back of the head. Indeed, they are made using a conductive polymer coating on conventional tattoo paper. After extensive study, the researchers at Graz University managed to develop the optimum thickness and composition to balance the ability to wear electrodes for a long time with signal quality when interacting with the scalp.

“Brain waves are in the low frequency range and EEG signals have a very low amplitude. They are much more difficult to capture in high quality than EMG or ECG signals,” said Laura Ferrari, one of the researchers behind the new electrodes.

Tests show near uniformity of signal fidelity and recordings between conventional commercial electrodes and these new ‘tattoos.’ They were successfully worn for prolonged periods offering a more affordable and convenient alternative

The new electrodes have also been shown to be safe for use with magneto-encephalography (MEG). This, researchers believe, represents a vital development since only wet, short lasting EEG electrodes have so far been shown to be compatible with MEG. It opens up the potential for long term brain monitoring under EEG and MEG simultaneously, which could help to solve a number of issues which are currently poorly understood by neuroscientists.

[1] https://bit.ly/2MtDIWb

Images courtesy © Greco – TU Graz