Time for a Medical Tattoo

Tattoo stickers are very much in vogue now.  While kids sport the superman/ batman/ Harry Potter variety, the youth have inclination for   intricate and abstract  patterns. Peel off the protective layer and stick it to anywhere on your body  and they stay put for a couple of days, and then quickly  wash  away  to the great relief  of parents.  The permanent tattoos of yesteryear, on the other hand  were done with a special ink through a painful pricking process, and  they stuck with you faithfully  for ever.  

This tattoo/ sticker concept had captured the imagination of science fiction writers a long long time ago,  but remained confined to that realm till now. There have been characters who held two way communications through electronic or bionic skin.   But it appears now that the  forerunners of medical tattoos are here.  Epidermal Electronic Skin (ESS) which can monitor, as of now brain, (EEG), cardiac(ECG) and muscle (EMG) activities has  been developed by a team of scientists(1).

Putting together such a device obviously demands close cooperation among scientists from multiple disciplines: material scientists, mechanical, electrical and electronic engineers and   of  course physicians  and skin specialists, to name a few.  Sure enough, it took a team of  26 scientists working in 6 different laboratories scattered across the globe  to come up with an electronic sticker, powered by ultra thin solar cells  to monitor these vital bio statistics. Electronic materials  such as silicon and gallium arsenide were made into  nanoribbons, nanowires  or nano membranes. These  could  then be easily  assembled as   winding or serpentine folds so that  they are flexible enough to deform and reform with the skin and  would cause least discomfiture to the wearer.    Radio frequency(RF) components were the choice for wireless communication. 

The team successfully recorded ECG, EMG and EEG signals and also found the reliability was matched  those obtained with conventional devices. With  the sticker on the forehead, the team could monitor brain activities through EEG signals and they observed a subtle difference in the signals with eyes open and shut. 

This indeed is a great step forward for continuous, non-invasive way of monitoring  physiological activities.  Once made commercially viable, the device will spell the end of bulky devices and lead wires that are cumbersome and uncomfortable.   In  one experiment with  the device mounted on the throat, the team demonstrates how it could enable speech impaired patients  to communicate. Great possibilities and greater hope for  quite a few.

  

Besides being a great medical help  this now opens up a whole new world of  amusing opportunities. The EEG, ECG and EMG signals are color coded; the medical tattoo then changes  colors in patches as the tempo of your physiological activities change.  If the wearer chooses to conceal the tattoo  under his/her sleeve then all the fun is lost, though.  

1. Science , p838-842,  Volume 333, 12^th August 2011