Patients in the future who need to be monitored in the long term will no longer need to wear bulky equipment – instead, they will get a special tattoo.
While the bulkiness of many medical monitoring devices has shrunk considerably from just a decade or two ago, many common long-term monitoring methods – such as electrocardiogram (ECG) and electromyography (EMG) – still require cumbersome and stiff devices.
Aside from not being comfortable, the gel on the electrodes dries out after a short time, making any long-term studies much more difficult.
However, new research led by the Graz University of Technology in Austria has found a novel method that would allow a patient to be ‘tattooed’ with sensors to overcome these mobility issues for ECGs and EMGs.
In a paper published to the journal Advanced Science, the team revealed that it had refined polymers capable of being printed on commercial temporary-tattoo paper, producing single or multiple electrode arrangements.
The tattoo electrodes are applied to the skin like temporary transfers and can hardly be felt by the wearer, while the external connections necessary for transmitting the signals are integrated directly into it.
Because they are less than one micrometre in thickness, the electrodes can be adapted perfectly to the uneven human skin, and can even be applied to parts of the body where traditional electrodes are not suitable, such as the face.
Need to go wireless
“With this method, we have managed to take a big step forward in further developing epidermal electronics,” said Francesco Greco of the research team.
“We are on a direct road to making an extremely economical and simple as well as versatile, applicable system which has enormous market potential.”
Another advantage of the tattoo monitor, the team added, is that even with a perforation of the tattoo – such as through the growth of a hair – the sensor can still perform perfectly.
Using existing systems, hair growth causes considerable inaccuracies in the readings but in testing, this sensor went three days with no problems in transmission.
Electrodes of different sizes and arrangements could also be produced using the printer and individually adapted to a body part needed to be analysed.
“We are working on the development of wireless tattoo electrodes with integrated transistors, which would make it possible to both send and receive signals,” Greco said.
“Not only could we measure impulses using this method, but we could also stimulate body regions in a targeted way.”