Researchers at the University of Twente have developed smart tattoos without the use of needles, which could be used as health sensors.
A new research paper from researchers of the University of Twente, Enschede, the Netherlands, compares a new micro-jet approach with classic needle technology, and outlines the potential of smart tattoos serving both cosmetic functions and as health sensors.
Smart tattoos as health sensors
Alongside their cosmetic role, possible functions of the smart tattoos as health sensors include warning the tattooed person that they have had too much sunlight exposure, or altering them to take medication.
How does a tattoo without the use of needles work?
The researchers have developed amicro-jet injection technology that does not require needles. It works using a laser to rapidly heating a fluid inside a microchannel on a glass chip to above boiling point, creating a vapour bubble which pushes out the liquid at speeds of up to 100 meter per second (360 km/h).
According to the University of Twente, the jet is about the diameter of a human hair and can penetrate through human skin. David Fernández Rivas, of the University of Twente, said: “You don’t feel much of it, no more than a mosquito bite.”
Fernández Rivas discusses the new technique in a video interview.
According to the University of Twente, the researchers experimented using commercially available inks and found that:
- Compared to a tattoo machine, the micro-jet consumes a small amount of energy;
- The micro-jet minimises skin damage;
- Injection efficiency is much higher; and
- There is no loss of fluids. And there is no risk of contaminated needles.
The remaining challenges for delivering smart tattoos
- However, the current micro-jet is a single one, while tattooing is often done using multiple needles to enable different types or ink colours. The volume of delivery also needs to be increased in the microjet.
- Also, the volume that can be ‘delivered’ by the microjet has to be increased. These are next steps in developing the needle-free technology.