Wearable Skin-sensor

Widely known as a leader in innovation, our customer wanted to launch a stretchable, ultra-thin wearable skin sensor designed to measure UV exposure. The UV exposure sensor patch increases personal awareness and understanding of sun exposure and harmful UV rays by providing readings via a smartphone app. The UV patch is a transparent adhesive that measures approximately one square inch by 50 micrometers thick (half the thickness of an average strand of hair). Applied directly to the skin, the patch contains UV sensitive dyes that change color with sun exposure, while other squares remain the same for baseline comparison.

Accurate UV-level reading was of the utmost challenge, requiring the development of specialized inks and a bespoke manufacturing process to ensure that each production batch achieved a stable and predictable UV exposure performance. Our customer also required a manufacturing partner who could create fully functioning samples within three months and scale manufacturing quickly to meet global demand. Finally, our customer had specific requirements around the look and feel of the product, and packaging. Users had to love the patch to wear it.

PCH took on the challenge to Design For Manufacturing (DFM) this first-of-its-kind product, and to scale production for global launch.

The first challenge to solve was to create specialized inks that would result in the precision UV-level reading expected by our customer. PCH created pre-mixed inks, combining varying proportions of UV dyes and UV blocker for each sensitive square of the UV Patch.

The UV patch has a combination of reactive and control squares. Eight of the squares are reactive (UV sensitive). These combine a unique and special combination of UV dye and UV blocker required for accurate measurement via the app. In addition, there are six reference color squares, and each has a unique special combination of UV dye and UV blocker. Finally, there are four reference colors and background color squares required for accurate UV exposure reading from the app. The PCH team went through several builds to refine the UV sensitivity tolerances.

In addition to creating specialized inks, PCH designed and implemented an agile manufacturing process that enabled a flexible production line to achieve a stable and predictable UV exposure for each batch of patches.

For quality control, PCH set up 14 unique and successive printing stations so that each UV sensitive square would have a unique exposure rate. This was essential to achieve a precise UV reading via the app. PCH implemented quality control measures, using a ‘sun simulator’ to ensure that the UV exposure curve would remain stable and specific throughout the manufacturing process, or that there was a constant balance between UV dye ink and UV blocker ink.

We always think with the consumer in mind – we understand the product journey from the concept phase to the consumer out-of-box experience. Therefore, we were pleased to work with our customer to create packaging that was both functional and attractive, protecting the product from environmental conditions such as light, temperature and humidity, while appealing to customers.

The results of this partnership speak for themselves. By working closely with our customer throughout, and fast-tracking the production process, PCH delivered the samples and packaging within three months of the project start, enabling our partner to achieve a strong press launch at the Consumer Electronic Show (CES) in 2016 & 2018 (Special Edition). Our focus is always peace of mind, delivering projects on time and on budget.

The patch was widely covered in the press as a valuable product to help consumers better understand and take action against harmful UV sun exposure. Within two years, PCH manufactured over one million patches and the product continues to grow in popularity.