We love energy harvesting here at ipXchange! When we come across a new PV cell manufacturer, we have to check it out, and when it’s this flexible, the design potential is vast. Engineers, meet Epishine!
At Embedded World 2024, ipXchange encountered some super-discrete, flexible solar cells from a disruptive manufacturer called Epishine. Eamon chatted to Marija to learn more, and she even showed us some reference designs that prove their efficiency and incognito integration potential.
Epishine’s flexible indoor solar cells
As Marija explains, Epishine produces its solar cells using a roll-to-roll process, making them extremely easy to manufacture. Epishine offers 8-, 6-, 4-, and 1-cell PV harvesters with remarkable performance in indoor applications.
Epishine’s solar cells can generate 22 µW/cm² at 500 lux, the typical level of light in an office. That said, they are able to generate electricity from as little as 1 lux. That’s a similar amount of light as the illumination from the full moon on a clear night! In terms of current, the 6-cell unit will produce around 150 µA in 500 lux.
Where can you use this technology?
In her hand, Marija holds an open-source asset tracker made in conjunction with RAKwireless. Epishine exchanged the 600-mAh battery for a solar energy harvesting system that uses an Epishine cell, some additional energy management/protection circuitry, and a much smaller 20-mAh battery. This extends the longevity of the tracker indefinitely, as opposed to having a battery life of 1 year. Sitting in 500 lux for 10 hours each day is enough to keep that battery topped up!
The flexibility of Epishine’s solar cells makes them great for installation on curved enclosures. Marija shows us a concept design for an earbud charging case, and as you can see, the solar cell is very discrete.
This technology is already being used for batteryless TV remote controls as shown by the background graphics.
Evaluating Epishine’s PV cells
Epishine has a development kit for testing its solar cells with an e-peas PMIC managing energy storage to an on-board supercapacitor that is capable of delivering up to 300 mA of output current. The included cell is the 50 x 50-mm 6-cell device that Marija shows us in the video.
If you have a commercial project and want to get connected with Epishine, follow the link below to ipXchange’s user-defined board page. There, you can fill in the form, and we’ll discuss your project with Epishine. We can even introduce you to other technology providers for your energy harvesting ecosystem.
Keep designing!