New Solar Powered Clothing Can Charge Portable Devices

EMTs and paramedics rely on portable electronic devices to perform their jobs, most of which rely on rechargeable batteries. What if there was a way to turn their clothing into wearable solar panels so the devices they count on could be recharged whenever they’re outside?

The Department of Homeland Security (DHS) Science and Technology Directorate (S&T), in partnership with Boston-based company Protect the Force and the University of Massachusetts Lowell, are developing a solar power charging fabric that can be worn by EMS personnel on the job.

Although the concept of solar power charging fabric sounds like science fiction, the reality is based on solid science.

“Solar power charging fabric is a collection of woven organic photovoltaic (OPV) wires, which convert light (solar energy), into electric energy,” explained S&T Program Manager Kimberli Jones-Holt. “The fabric is woven from single-filament (monofilament) threaded yarns, which are made from ultra-smooth stainless wires. These wires are coated with various photoactive layers and then wrapped with a copper secondary wire and subsequently encased with an ultraviolet (UV) curable resin covering.”

To create wearable clothing, the OPV filaments (PV yarn) are woven together with Nomex yarn to make a workable fabric. Nomex is often used in protective clothing due to its ability to withstand high temperatures, flame resistance, and no-drip, no-melt qualities. The ends of the OPV filaments are connected to electrical conductors (busbars) to collect the power generated by the resulting solar power charging fabric.

As for wearability? “The PV yarn is highly flexible and can be integrated into fabric quite easily,” Jones-Holt told EMS World. “Thanks to those unique characteristics, PV yarn can be woven into any desirable fabric patterns such as satin or twill structures, or any other cloth conventionally used in the textile industry.” This means that PV fabric has a very natural feeling, smooth texture, and high breathability, allowing it to be made into the standard duty uniforms worn by EMS personnel without any comfort or weight issues.

The electrical output of today’s solar power charging fabric is not large. Currently, a small swatch of solar power charging fabric, having a surface area of about 7.75 square inches, can generate 0.02 watts (20 mW) of power.

When a larger area of fabric is used to create an EMS shirt, the solar power delivered to a wearable battery/supercapacitor “would be sufficient enough to power a device like a glucometer that can be worn a week or two before needing charging,” said Jones-Holt. The current model would see the power storage device equipped with a USB port to connect to a glucometer or other rechargeable device.

As has already been the case with larger rigid solar panels, the solar energy harvesting/power conversion capacity of this fabric will likely increase as the technology evolves. But even now, the current version of this fabric “would provide EMS personnel with the ability to power small electronic devices such as glucometers, portable blood analyzers, and communication tools, depending on the amperage required by these devices,” Jones-Holt said. “As the technology progresses, the range of devices will expand as novel sensors and diagnostic technologies become mature enough and adaptable. Meanwhile, as the pool of portable diagnostic and communication tools increases, the need for a technology such as solar power charging fabric will increase.”

As revolutionary as solar power charging fabric may seem, its benefits are within our grasp. The science of the fabric itself has already been worked out, but the wearable solar power module technology is still evolving. Nevertheless, “we anticipate it could reach full maturity for use by EMS personnel and the first responder community within the next 1.5 years,” said Jones-Holt.

James Careless is a frequent contributor to EMS World.