Researchers at the universities of Coimbra and the US Carnegie Mellon have developed a method of producing electronic tattoos in a traditional printer, radically reducing the cost of this device with multiple applications such as health monitoring.
“A team of researchers from the Institute of Systems and Robotics (ISR) at the Faculty of Science and Technology of the University of Coimbra (FCTUC) and the Carnegie Mellon University (CMU) in Pittsburgh found a method to produce electronic tattoos by printing inks (inkjet), “that college announced today.
The new method “simplifies production and dramatically reduces the cost of these devices with such broad implications as continuous monitoring of user-health or tactile control of the dashboard,” the FCTUC said in a statement today.
Mahmoud Tavakoli, scientific project manager and director of ISR’s ‘Soft and Printed Microelectronic’ Laboratory, reveals that a simple and low-cost way of printing flexible conductive circuits with a 2D printer (two dimensions) has been found, since “these tattoos can be easily printed and transferred to any surface. ”
“The circuit is projected on the computer and after ten minutes we have our printed circuit,” he says, quoted by FCTUC, the researcher, noting that “the biggest advantage of producing in 2D is the low cost of the equipment and can be produced in large quantities. ”
So far, “the existing alternatives to producing this type of ultrathin circuits required labour intensive, high production costs and were exclusively manufactured in specialized clean-room laboratories designed to maintain extremely low particle levels, such as dust or organisms carried by air, “reports the FCTUC.
These tattoos are ultra-thin and easily transferred with water to the skin or clothing, in the same way, that a temporary tattoo is applied with the use of a damp sponge, he adds.
“By being placed on the skin, [tattoos] allow continuous monitoring of the user’s health and control factors such as muscle activity, breathing, body temperature, heart rate, brain activity or even emotions,” explains FCTUC.
These tattoos have also proved, according to Mahmoud Tavakoli, to be effective in monitoring muscle activity.
Although printing circuits with a 2D printer is not new, so far these circuits have lost conductivity when stretched.
“This is the first time that there is a method to print circuits that can be stretched with a traditional inkjet printer at room temperature. Unlike other methods, this eliminates the need to cure the ink at high temperatures and is compatible with which allows us to create ultrathin circuits called electronic tattoos. These circuits are composed of silver nanoparticles coated with liquid metal and can be stretched up to twice their size without losing their conductivity.
For example, for people with spinal cord injuries who can not walk, create a way to get these tattoos to be applied in the marrow in order to stimulate it and reactivate the nerves so that they work again “.
Outside of health, these electronic circuits can be used on any 3D surface, such as the car control panel, in order to allow a touch-activated control of the various functionalities of the car.
The discovery of this method resulted in “several innovative applications in the field of printed circuits that were patented in 2017 and published in the journals Advanced Materials and ACS applied materials and interfaces in 2018,” concludes FCTUC.