Scientists identify low-cost production method for wearable skin patches

The discovery could see these new patches outperform traditional monitoring tools such as cardiac event monitors, according to the team; and they could also have a cosmetics use as they can monitor skin condition and hydration levels.

The cosmetics industry is no stranger to such technology with the likes of L’Oréal demonstrating how a wearable device could have a big future for thermal evaluations in a non-invasive manner​, as a skin patch it is looking into could be used to find out the condition of the skin at certain points.

The skin is, after all, our body’s largest organ and can actually communicate with us, says the French cosmetics maker, who says such information obtained can provide information and analysis of the effectiveness of active compounds and help development of products targeting specific issues.

“Developments in wireless technology will provide a path to continuous monitoring of skin properties and function using these concepts,”​ says L’Oréal.

Cost and time​

The stumbling block for such technology has been that producing patches is a lengthy and costly process, but scientists from the Cockrell School of Engineering at The University of Texas at Austin published a paper on their patent-pending process in Advanced Materials​, stating they may have found a solution.

Led by Assistant Professor Nanshu Lu, the team's manufacturing method aims to construct disposable tattoo-like health monitoring patches for the mass production of epidermal electronics, a popular technology that Lu helped develop in 2011.

The team's breakthrough is a repeatable ‘cut-and-paste’ method that cuts manufacturing time from several days to only 20 minutes as the team believe Lu’s method can be transferred to roll-to-roll manufacturing, which can reduce the cost significantly for mass production and the time it takes.

Process​

The two-step process starts with inexpensive, pre-fabricated, industrial-quality metal deposited on polymer sheets.

First, an electronic mechanical cutter is used to form patterns on the metal-polymer sheets, then, after removing excessive areas; the electronics are printed onto any polymer adhesives, including temporary tattoo films.

After producing the cut-and-pasted patches, the researchers tested them as part of their study, finding their newly fabricated patches picked up body signals that were stronger than those taken by existing medical devices, including an ECG/EKG, a tool used to assess the electrical and muscular function of the heart.

The team also found that their patch conforms almost perfectly to the skin, minimizing motion-induced false signals or errors.

While these patches have widespread medical applications they also have cosmetics relevance as they can track vital skin signs.

The UT Austin method is the first dry and portable process for producing these electronics, which, unlike the current method, does not require a clean room, wafers and other expensive resources and equipment.

Instead, the technique relies on freeform manufacturing, which is similar in scope to 3-D printing but different in that material is removed instead of added.