12/07/2012 10:42 am ET

Temporary Tattoo Gauges Body's Metabolic Stress

A temporary tattoo-like sensor that looks like a smiley face could help to monitor metabolic stress in the body, according to new research.

The sensor is applied just like a regular temporary tattoo -- where it's transferred onto the skin with a warm water-soaked paper towel -- and works to monitor metabolic stress in the body as a result of physical exertion, according to the research published in the journal Analyst.

The smiley face isn't just for looks -- the eyes of the face are actually electrodes, while the ears can be connected to a measuring device.

"We wanted a design that could conceal the electrodes," study researcher Vinci Hung, a Ph.D. candidate at the University of Toronto Scarborough, who worked on the sensor while at the University of California, San Diego, said in a statement. "We also wanted to showcase the variety of designs that can be accomplished with this fabrication technique."

The tattoo could have future uses for metabolic diseases, or to indicate when a person has overexerted his or herself, noted the researchers.