Circuit sensor tattoos: The future of biometrics

Wearable circuit tattoos may soon be a revolutionary technology that could help monitor one's health. Scientists from Penn State University who developed the circuit sensor tattoos were able to print circuits directly onto skin without the use of heat. The electronic body art doubles as a sensor that tracks an individual's biometric readings such as heartbeat, body temperature and blood oxygen levels.

As technology has seen much evolution from watches to electrodes and smart gadgets, wearable sensors are now gradually making their way into everyday life to provide more accurate and precise measurements.

According to the study published in the journal ACS Applied Materials and Interfaces , one of its authors, Dr. Ling Zhang said:

"In this article, we report a simple yet universally applicable fabrication technique with the use of a novel sintering aid layer to enable direct printing for on-body sensors."

The new wearable technology was conceptualised and built with the help of scientists at the Harbin Institute of Technology in China.

Although biosensing "tattoos" are not so much a novel idea. Engineers have earlier developed something similar. However, this required too much heat to be applied on human skin which was deemed unsafe.

Typically, to do this, a technician would need high temperatures to allow metallic components of sensors to bond together and mould onto the skin. The new technique now enabled researchers to lower the temperature for sintering which could reach up to 300C down to room temperature which is about 20-22C.

In an article on UPI, scientists were able to stick the device onto skin with the newly developed layer made out of polyvinyl alcohol paste and calcium carbonate. It only required the use of a hairdryer running on cool settings to mould it onto the skin surface.

The circuit sensor tattoo was tested to monitor body temperature, blood oxygen levels, heart rhythms as well as humidity. It can be removed prior to a shower without damaging the skin and can be reused and stuck again after a bath.

"That's especially important for people with sensitive skin, like the elderly and babies. The device can be useful without being an extra burden to the person using it or to the environment.", Dr. Cheng said.

Scientists are hopeful this technology can also be designed to track symptoms associated with Covid-19 infection in the near future.