Engineers are taking important steps toward a future in which skin-mounted electronics could monitor individuals in a natural environment and even offer the potential for human-computer interfacing — all with the flexibility and comfort of a temporary tattoo.
Researchers at the University of Illinois and Northwestern University recently developed a type of patch with a circuit that bends, wrinkles, and stretches with the mechanical properties of skin. The patches are mounted on a thin sheet of water-soluble plastic, then laminated to the skin with water, like a temporary tattoo.
All this was made possible through the researchers' development of a device geometry called filamentary serpentine, in which the circuits are fabricated as tiny, squiggled wires. When mounted on thin, soft rubber sheets, the wavy, snakelike shape allows them to bend, twist, scrunch, and stretch while maintaining functionality.
"The blurring of electronics and biology is really the key point here," said Northwestern University engineering professor Yonggang Huang. "All established forms of electronics are hard, rigid. Biology is soft, elastic. It's two different worlds. This is a way to truly integrate them."