It was recently announced that researchers from Northwestern University and the University of Illinois at Urbana-Champaign have developed “tattoo electronics”. These are wireless electronics so flexible and thin they can be applied to the skin and forgotten.
According to the release, the high-performance epidermal electronic system mounts directly onto the skin with the ease, flexibility and comfort of a temporary tattoo. The system could be used for monitoring brain, heart and muscle tissue activity; wound measurement and treatment; biological and chemical sensing; computer gaming and covert communications.
The challenge for Huang and his colleagues was to make the thickness and stiffness of the electronic system similar to that of skin. The researchers accomplished this through a serpentine design of electronic nanoribbons. The circuits for the various components are fabricated as tiny wires. When mounted on lightweight and stretchable membranes, the wavy, snakelike shape allows the wires to bend, twist, scrunch and stretch while maintaining functionality.
The electronics also can be removed easily. They adhere to the skin the same way it is believed a gecko’s foot adheres temporarily to a surface: through an electrostatic phenomenon called the van der Waals force. Tape or glue is not necessary.
The system features electrophysiological and physical sensors and wireless power and communication modules. It is free of cumbersome wires, making it practical for use outside a research lab or clinic, in a natural environment. The researchers also show that their system’s EEG, ECG and EMG recordings are comparable to signals collected using bulky commercial devices that require tape for mounting to the skin.
They also demonstrate their system’s potential for use in human-machine interfaces. The electronics can be mounted on a person’s throat and, after training, the system can translate the simple spoken commands “up,” “down,” “left” and “right” into directions to control the video game Sokoban. This capability could prove useful to patients with muscular or neurological disorders, such as amyotrophic lateral sclerosis, or ALS, who could use the electronic patches to communicate or interface with computers. Another demonstration shows the electronics can be integrated with commercially available temporary tattoos, if there is a desire to conceal the electronics.