Blue medical sensor that measures pH level through skin. The "eyes" of the face are working electrodes that can be accessed any time to retreive data. (via University of Toronto Scarborough)
Temporary tattoos do not have much appeal for people past adolescence, but researcher Vinci Hung, from the University of Toronto Scarborough, has developed one that will catch the attention of athletes, coaches and physicians.
These temporary tattoos are just like the ones you get from the 25-cent machines. You wet the paper and stick them onto your skin. The difference is these contain solid-contact, ion-selective electrodes (ISEs) will eventually be manufactured out of different materials to detect different substances in the sweat secreted by skin. Substances such as sodium, potassium and magnesium can be indicative of different conditions like Addison’s disease (a metabolic disorder) and thus detecting them is oh much importance to medical or cosmetic researchers.
Currently, Hung, a PhD candidate in the department of Physical & Environmental Sciences at the University of Toronto Scarborough, has developed a potentiometric, temporary tattoo sensor that can quickly detect a wide range of pH changes in sweat or skin secretions. This particular application could alert athletes, trainers and coaches when someone is fatigued or dehydrated, and it could be used to tailor workout routines.
These devices are already used for these purposes. What makes Hung’s invention different is the size, flexibility and adhesiveness as opposed to the current big, bulky and difficult-to-wear devices. This first iteration is a smiley face, just a few centimeters across. The concealed electrodes are actually in the eyes, and the ears are contacts for measurement devices.
Hung and her team have developed a manufacturing method that can make a wide range of these stickers. This method involves conventional solid-contact polymer ISE production and uses a regular screen printer to print consecutive layers of silver, carbon modified with carbon fiber, insulating layers of different inks with the last layer of electropolymerized aniline composing the sensor’s surface. All of this is printed on a commercially available temporary tattoo paper.
Hung received help from professor Joseph Wang, an expert in nanoengineering and biosensor technology, when she was working at the University of California in San Diego. The article detailing her work was co-authored by Kagan Kerman, her PhD supervisor and professor of bio-analytical chemistry at the University of Toronto Scarborough. This piece is published in the Royal Society of Chemistry’s journal, Analyst.
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