Tag Archives: ARM-based SAM4L MCU

Solar-powered batteries woven into fabric for wearables

A new generation of solar-powered wearable electronics could soon be hitting the streets, with batteries inconspicuously woven into clothing fibers or incorporated into watchbands.

Image Credit: Adafruit

As a recent article published in Nano Letters notes, electronic textiles have the potential to integrate smartphone functions into clothes, eyeglasses, watches and materials worn on the skin. Possibilities range from the practical – for example, allowing athletes to monitor vital signs – to the aesthetic, such as lighting up patterns on clothing.

However, the article identified current battery technology as the primary “bottleneck,” responsible for slowing progress toward the development of a wider range of flexible e-fabrics and materials. Indeed, a number of wearable electronic items, such as smartwatches and Google Glass, still require a charger with a cord.

To unlink smart technology from the wall socket, a research team headed by Taek-Soo Kim, Jung-Yong Lee and Jang Wook Choi had to rethink what materials are best suited for use in a flexible, rechargeable battery that’s also inexpensive.

Image Credit: Adafruit

Ultimately, the team decided to test unconventional materials, discovering that they could coat polyester yarn with nickel and carbon – using polyurethane as a binder and separator to produce a flexible battery that kept working even after being folded and unfolded many times. The researchers also managed to integrate lightweight solar cells to recharge the battery without disassembling it from clothing or requiring the wearer to plug in.

As we’ve previously reported on Bits & Pieces, analysts at ABI Research have determined that wearable wireless device revenues will grow to exceed $6 billion in 2018. Of the four segments tracked, sports, fitness and wellness are the largest, never dropping below 50% share of all device shipments over the forecast period.

Amulet Pendant: Powered by Atmel’s ARM-based SAM4L MCU.

“Fitness activity trackers are quickly gaining popularity in the market,” confirmed ABI Research senior analyst Adarsh Krishnan. “Different from other more single-use or event-centric devices, activity trackers monitor multiple characteristics of the human body including movement, calories burned, body temperature and sleep tracking.”