Nanoengineers have combined a popular fad with medical observation. A tattoo-like electronic patch placed on the body can deliver signals about your heart, muscles, or brain to a computer.

The challenge was to imbed electronics into a flexible, comfortable, small patch that could be applied to the skin. The work of scientists, including John Rogers at the University of Illinois at Urbana Champaign combined with that of a group led by Northwestern University engineering professor Yonggang Huang produced the amazing results.

Huang explained: "The blurring of electronics and biology is really the key point here. 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." Huang appeared a video regarding "Stretchable Electronics" in late 2008.

Tricoder of 21st Century - Skin Electronics i.e. harmless patches for EEG, EMG and similar measurements
Tricoder of 21st Century – Skin Electronics i.e. harmless patches for EEG, EMG and similar measurements

The researchers used simple adaptations of techniques used in the semiconductor industry, so the patches can be scaled and easily manufactured. They employ a "transfer printing" fabrication process .Certain versions of the technology are being looked at for commercial use by mc10, a company Rogers co-founded. mc10 transforms rigid, planar electronics into new types of systems that can bend, stretch and wrap into novel form factors. They address military, consumer, and industrial uses in addition to medical applications.

The medical patches utilize a device geometry called filamentary serpentine, in other words they have turned electronic circuits into thin squiggly, flexible lines. The epidermal electronics include sensors, LEDs, transistors, radio frequency capacitors, wireless antennas, conductive coils, and even solar cells for power. The circuits rest on a thin, soft rubber sheet encased in a water-soluble protective polymer. The tattoo approach replaces conductive gel, and tape that can cause a rash and skin-penetrating pins or bulky wires that cause discomfort and inconvenience to the wearer. The patches move with the skin, stretching or twisting while remaining functional.

Tattoo records electrical activity of brain waves.  Photo Credit: John Rogers
Tattoo records electrical activity of brain waves.  Photo Credit: John Rogers

A frown won?t interfere with an EEG reading taken from the patch on a forehead. Bending the wrist won?t interfere with a patch placed there for an EMG reading. Currently, signals from the body are delivered to a computer by a thin wire. A wireless transmission is planned. Data from the body has been collected accurately for up to six hours. Devices have been worn up to 24 hours with no evident skin irritation. Since skin cells slough off regularly, the time a device will adhere to the body is limited according to Rogers.

Monitoring is just the beginning. The researchers foresee the devices being used to help control prosthetic limbs or to assist in treating muscle injuries by stimulating muscle contractions. They could even help people use their throat muscles as a means of communication beyond verbalizing.

For the self-conscious, or those who simply want to make a fashion statement, the epidermal electronics device can be designed as a fancy tattoo to make it undistinguishable as a medical appliance.