A team of engineers from the University of Illinois at Urbana-Champaign and Northwestern University, Evanston, IL, have demonstrated thin, soft stick-on patches that stretch and move with the skin and incorporate commercial, off-the-shelf chip-based electronics, can support sophisticated wireless health monitoring.

The patches incorporate a unique microfluidic construction with folded wires to allow the patch to bend. (Credit: Felice Frankel)

The patches stick to the skin like a temporary tattoo and incorporate a unique microfluidic construction with wires folded like origami to allow the patch to bend and flex without being constrained by the rigid electronics components.

Their uses could include everyday health tracking, sending real-time updates to your cellphone or computer, and may even revolutionize clinical monitoring such as EKG and EEG testing, all without the use of bulky wires, pads, or tape.

The researchers did a side-by-side comparison with traditional EKG and EEG monitors and found the wireless patch performed equally to conventional sensors, while being significantly more comfortable for patients. Such a distinction is crucial for long-term monitoring, situations such as stress tests or sleep studies when the outcome depends on the patient’s ability to move and behave naturally, or for patients with fragile skin like premature newborns.

The multi-university team used soft microfluidic designs to address the challenge of integrating relatively big, bulky chips with the soft, elastic base of the patch. The patch is constructed of a thin elastic envelope filled with fluid. The chip components are suspended on tiny raised support points, bonding them to the underlying patch but allowing the patch to stretch and move.

One of the biggest engineering challenges was the design of the tiny wires connecting the electronics components. The serpentine-shaped wires are folded like origami, so that no matter which way the patch bends, twists, or stretches, the wires can unfold in any direction to accommodate the motion. Since the wires stretch, the chips don’t have to.

Skin-mounted devices can be placed on multiple parts of the body for a deeper set of information than would be possible with devices that are not well coupled with the skin. Future uses might even include the ability to detect motions associated with Parkinson’s disease at its onset or to catch other health conditions before experiencing pain, discomfort, and illness.”